The Journal of Allergy and Clinical Immunology - Articles in Press

Delayed-onset adenosine deaminase deficiency: Strategies for an early diagnosis - Corrected Proof

2012-05-14

Adenosine deaminase (ADA) deficiency is a well-known cause for severe combined immunodeficiency (SCID). However, hypomorphic mutations in the ADA gene can lead to a different immunodeficiency with variable phenotype including signs of immune dysregulation. Early diagnosis and therapeutic management often remain a challenge. We report on 2 ADA-deficient patients with delayed-onset (P1) and late-onset phenotype (P2) illustrating these difficulties and describe how newborn screening could have facilitated early diagnosis in one of these patients.

T- and B-cell defects in a novel purine nucleoside phosphorylase mutation - Corrected Proof

Raz Somech, Atar Lev, Amos J. Simon, Suhair Hanna, Amos Etzioni — 2012-05-14

Two autosomal recessive genetic disorders of the purine salvage pathway, including adenosine deaminase and purine nucleoside phosphorylase (PNP) deficiencies, are associated with immunodeficiency. In PNP deficiency, the hallmark pathophysiology is the accumulation of deoxyguanosine triphosphate toxic metabolites, particularly in lymphocytes. Consequently, T-cell development is impaired, and there is variable B-cell dysfunction. Increased risk of autoimmune disorders (eg, hemolytic anemia, thrombocytopenia, neutropenia, and thyroiditis) is a characteristic of PNP deficiency, and it is seen in approximately one third of the cases. Autoimmune features may be recognized clinically before the onset or identification of immunodeficiency. Characterization of the B-cell immunodeficiency in PNP deficiency is still incomplete, and it is mainly attributed to impaired T-cell function resulting in autoimmune phenomena. Serum immunoglobulin levels can be normal to near-normal, but the production of specific T-cell–dependent antibodies is reduced. A similar combination of effects is likely to be operative in patients with delayed onset or partial adenosine deaminase deficiency who also show variable residual B-cell function and autoimmunity. The diagnosis of PNP is usually suggested by a low level of serum uric acid, supported by reduced PNP activity and confirmed by molecular gene analysis. Normally, T-cell maturation in the thymus and B-cell maturation in the bone marrow progress through distinct stages that are defined phenotypically by the expression of their specific receptors (T-cell receptors [TCRs] and B-cell receptors [BCRs], respectively). This process, which involves DNA rearrangement, results in the formation of normal numbers of functional and mature cells that carry coding joints in their rearranged fragments. Stable by-product circles, known as TCR excision circles (TRECs) or the kappa-deleting recombination excision circles (KRECs), are created during the excision of the DNA fragments in T and B cells, respectively. These signal joint circles, which are present solely in newly derived thymic or bone marrow cells and not in replicating cells during mitosis, allow indirect quantification of thymic and bone marrow output. In contrast, cells containing only coding joints may reflect the peripheral replication history of the lymphocyte subsets. Taken together, the ratio between genomic coding joints and signal joints in these cells reflects both peripheral cell divisions in response to antigen exposure and the export of new T cells from the thymus and B cells from the bone marrow. Simultaneous quantification of TRECs and KRECs, which contain the required signal joint rearrangement in patients with primary immunodeficiency after bone marrow transplantation, was recently proposed for monitoring the appearance of newly derived thymic and bone marrow cells. The amounts of TRECs and KRECs are determined by real-time quantitative PCR. Reactions are performed by using genomic DNA extracted from patients' PBMCs and PCRs that contain specific primers and probes as previously described in detail.

Allergen specificity of IgG4-expressing B cells in patients with grass pollen allergy undergoing immunotherapy - Corrected Proof

2012-05-14

Background: Serum IgG4 responses to allergen immunotherapy are well documented as blocking allergen binding to receptor-bound IgE on antigen-presenting cells and effector cells, but the molecular characteristics of treatment-induced IgG4, particularly in relation to expressed antibody, are poorly defined.Objectives: We aimed to clone and express recombinant IgG4 from patients receiving grass pollen immunotherapy using single B cells to obtain matched heavy- and light-chain pairs.Methods: IgG4+ B cells were enriched from blood samples taken from 5 patients receiving grass pollen immunotherapy. Matched heavy- and light-chain variable-region sequences were amplified from single IgG4+ B cells. Variable regions were cloned and expressed as recombinant IgG4. Binding analysis of grass pollen–specific IgG4 was performed by using surface plasmon resonance. Functional assays were used to determine IgE blocking activity. In a separate experiment grass pollen–specific antibodies were depleted from serum samples to determine the proportion of grass pollen–specific IgG4 within total IgG4.Results: Depletion of grass pollen–specific antibodies from serum led to a modest reduction in total IgG4 levels. Matched heavy- and light-chain sequences were cloned from single IgG4+ B cells and expressed as recombinant IgG4. We identified an IgG4 that binds with extremely high affinity to the grass pollen allergen Phl p 7. Furthermore, we found that a single specific mAb can block IgE-mediated facilitated allergen presentation, as well as IgE-mediated basophil activation.Conclusion: Although increases in IgG4 levels cannot be wholly accounted for within the allergen-specific fraction, allergen immunotherapy might result in the production of high-affinity allergen-specific blocking IgG4.

Parasites and allergic disease: Another piece of the puzzle - Corrected Proof

Robert K. Bush — 2012-05-14

Immunity to parasitic infections principally involves innate and adaptive TH2 responses and is accompanied by the development of IgE antibodies to parasite antigens. Epidemiologic and experimental studies suggest that helminth infections can modulate allergic disease, but cross-reactivity between helminth antigens and allergens that induce human allergic disease has been described. Tropomyosin from filarial parasites can induce IgE antibodies that cross-react with house dust mite allergens, and similarly, IgE responses to tropomyosins from Ascaris species cross-react with cockroach allergens.

Role of nicotinic receptors and acetylcholine in mucous cell metaplasia, hyperplasia, and airway mucus formation in vitro and in vivo - Corrected Proof

2012-05-11

Background: Airway mucus hypersecretion is a key pathophysiologic feature in a number of lung diseases. Cigarette smoke/nicotine and allergens are strong stimulators of airway mucus; however, the mechanism of mucus modulation is unclear.Objectives: We sought to characterize the pathway by which cigarette smoke/nicotine regulates airway mucus and identify agents that decrease airway mucus.Methods: IL-13 and γ-aminobutyric acid type A receptors (GABAARs) are implicated in airway mucus. We examined the role of IL-13 and GABAARs in nicotine-induced mucus formation in normal human bronchial epithelial (NHBE) and A549 cells and secondhand cigarette smoke–induced, ovalbumin-induced, or both mucus formation in vivo.Results: Nicotine promotes mucus formation in NHBE cells; however, the nicotine-induced mucus formation is independent of IL-13 but sensitive to the GABAAR antagonist picrotoxin. Airway epithelial cells express α7-, α9-, and α10-nicotinic acetylcholine receptors (nAChRs), and specific inhibition or knockdown of α7- but not α9/α10-nAChRs abrogates mucus formation in response to nicotine and IL-13. Moreover, addition of acetylcholine or inhibition of its degradation increases mucus in NHBE cells. Nicotinic but not muscarinic receptor antagonists block allergen- or nicotine/cigarette smoke–induced airway mucus formation in NHBE cells, murine airways, or both.Conclusions: Nicotine-induced airway mucus formation is independent of IL-13, and α7-nAChRs are critical in airway mucous cell metaplasia/hyperplasia and mucus production in response to various promucoid agents, including IL-13. In the absence of nicotine, acetylcholine might be the biological ligand for α7-nAChRs to trigger airway mucus formation. α7-nAChRs are downstream of IL-13 but upstream of GABAARα2 in the MUC5AC pathway. Acetylcholine and α7-nAChRs might serve as therapeutic targets to control airway mucus.

Intravenous immunoglobulin attenuates airway inflammation through induction of forkhead box protein 3–positive regulatory T cells - Corrected Proof

2012-05-07

Background: Intravenous immunoglobulin (IVIG) is a frequently used disease-modifying therapy for a large spectrum of autoimmune and inflammatory conditions, yet its mechanisms of action are incompletely understood. Using a robust murine model of antigen-driven allergic airways disease, we have demonstrated that IVIG markedly improves ovalbumin (OVA)–induced airway hyperresponsiveness characterized by 4- to 6-fold enhancement in regulatory T (Treg) cells in pulmonary and associated lymphoid tissues.Objective: We sought to determine whether IVIG induces antigen-specific Treg cells and to address cellular interactions that lead to induction of Treg cells by IVIG.Methods: C57Bl/6 mice were sensitized and challenged by means of intranasal OVA exposure. IVIG or albumin control was administered 24 hours before challenge. Treg cells were tracked by using green fluorescent protein (GFP)-forkhead box protein 3 (Foxp3) knock-in reporter mice (Foxp3GFP), and Treg cell and dendritic cell (DC) phenotypes and activities were elucidated by using coculture and flow cytometry.Results: IVIG therapy of OVA-sensitized and OVA-challenged mice induced antigen-specific forkhead box protein 3 (Foxp3)–positive Treg cells from non-Treg cell precursors. The induced Treg cells home specifically to the lungs and draining lymph nodes and have greatly potentiated suppressive activity compared with that seen in Treg cells purified from control mice. Induction of Treg cells is mediated by tolerogenic DCs generated after IVIG exposure. Compared with albumin-treated, OVA-exposed mice, IVIG-primed DCs express altered Notch ligands, including increased Delta-4 and reduced Jagged-1 levels, reflecting decreased TH2 polarization. Furthermore, IVIG-primed DCs can stimulate Treg cell differentiation from uncommitted Foxp3−CD4+ T cells ex vivo, and adoptive transfer of IVIG-primed DCs abrogates airway hyperresponsiveness and induces Treg cells.Conclusion: The anti-inflammatory effects of IVIG therapy can be mediated by the immunomodulation of DCs, creating a bridge that induces antigen-specific, highly suppressive Treg cells.

Modulation of FcεRI-dependent mast cell response by OX40L via Fyn, PI3K, and RhoA - Corrected Proof

2012-05-07

Background: The interaction of mast cells (MCs) with regulatory T cells through the OX40 ligand (OX40L):OX40 axis downregulates FcεRI-dependent immediate hypersensitivity responses both in vitro and in vivo. Little is known on OX40L-mediated intracellular signaling or on the mechanism by which OX40L engagement suppresses MC degranulation.Objective: We explored the role of OX40L engagement on IgE/antigen-triggered MCs both in vitro and in vivo.Methods: The soluble form of OX40 molecule was used to selectively trigger OX40L on MCs in vitro and was used to dissect OX40L contribution in an in vivo model of systemic anaphylaxis.Results: OX40L:OX40 interaction led to the recruitment of C-terminal src kinase into lipid rafts, causing a preferential suppression of Fyn kinase activity and subsequent reduction in the phosphorylation of Gab2, the phosphatidylinositol 3-OH kinase regulatory subunit p85, and Akt, without affecting the Lyn pathway. Dampening of Fyn kinase activity also inhibited RhoA activation and microtubule nucleation, key regulators of MC degranulation. The in vivo administration of a blocking antibody to OX40L in wild-type mice caused enhanced immediate hypersensitivity, whereas the administration of soluble OX40 to regulatory T-cell–depleted or OX40-deficient mice reduced MC degranulation.Conclusions: The engagement of OX40L selectively suppresses Fyn-initiated signals required for MC degranulation and serves to limit immediate hypersensitivity. Our data suggest that soluble OX40 can restore the aberrant or absent regulatory T-cell activity, revealing a previously unappreciated homeostatic role for OX40L in setting the basal threshold of MC response.

African ancestry and lung function in Puerto Rican children - Corrected Proof

2012-05-07

Background: Puerto Rican and African American subjects share a significant proportion of African ancestry. Recent findings suggest that African ancestry influences lung function in African American adults.Objective: We sought to examine whether a greater proportion of African ancestry is associated with lower FEV1 and forced vital capacity (FVC) in Puerto Rican children independently of socioeconomic status, health care access, or key environmental/lifestyle factors.Methods: We performed a cross-sectional case-control study of 943 Puerto Rican children aged 6 to 14 years with (n = 520) and without (n = 423) asthma (defined as physician-diagnosed asthma and wheeze in the prior year) living in Hartford, Connecticut (n = 383), and San Juan, Puerto Rico (n = 560). We estimated the percentage of African racial ancestry in study participants using genome-wide genotypic data. We tested whether African ancestry is associated with FEV1 and FVC using linear regression. Multivariate models were adjusted for indicators of socioeconomic status and health care and selected environmental/lifestyle exposures.Results: After adjustment for household income and other covariates, each 20% increment in African ancestry was significantly associated with lower prebronchodilator FEV1 (−105 mL; 95% CI, −159 to −51 mL; P < .001) and FVC (−133 mL; 95% CI, −197 to −69 mL; P < .001) and postbronchodilator FEV1 (−152 mL; 95% CI, −210 to −94 mL; P < .001) and FVC (−145 mL; 95% CI, −211 to −79 mL; P < .001) in children with asthma. Similar but weaker associations were found for prebronchodilator and postbronchodilator FEV1 (change for each 20% increment in African ancestry, −78 mL; 95% CI, −131 to −25 mL; P = .004) and for postbronchodilator FVC among children without asthma.Conclusions: Genetic factors, environmental/lifestyle factors, or both correlated with African ancestry might influence childhood lung function in Puerto Rican subjects.

High titers of IgE antibody to dust mite allergen and risk for wheezing among asthmatic children infected with rhinovirus - Corrected Proof

2012-05-07

Background: The relevance of allergic sensitization, as judged by titers of serum IgE antibodies, to the risk of an asthma exacerbation caused by rhinovirus is unclear.Objective: We sought to examine the prevalence of rhinovirus infections in relation to the atopic status of children treated for wheezing in Costa Rica, a country with an increased asthma burden.Methods: The children enrolled (n = 287) were 7 through 12 years old. They included 96 with acute wheezing, 65 with stable asthma, and 126 nonasthmatic control subjects. PCR methods, including gene sequencing to identify rhinovirus strains, were used to identify viral pathogens in nasal washes. Results were examined in relation to wheezing, IgE, allergen-specific IgE antibody, and fraction of exhaled nitric oxide levels.Results: Sixty-four percent of wheezing children compared with 13% of children with stable asthma and 13% of nonasthmatic control subjects had positive test results for rhinovirus (P < .001 for both comparisons). Among wheezing subjects, 75% of the rhinoviruses detected were group C strains. High titers of IgE antibodies to dust mite allergen (especially Dermatophagoides species) were common and correlated significantly with total IgE and fraction of exhaled nitric oxide levels. The greatest risk for wheezing was observed among children with titers of IgE antibodies to dust mite of 17.5 IU/mL or greater who tested positive for rhinovirus (odds ratio for wheezing, 31.5; 95% CI, 8.3-108; P < .001).Conclusions: High titers of IgE antibody to dust mite allergen were common and significantly increased the risk for acute wheezing provoked by rhinovirus among asthmatic children.

Genome-wide association study of the age of onset of childhood asthma - Corrected Proof

2012-05-04

Background: Childhood asthma is a complex disease with known heritability and phenotypic diversity. Although an earlier onset has been associated with more severe disease, there has been no genome-wide association study of the age of onset of asthma in children.Objective: We sought to identify genetic variants associated with earlier onset of childhood asthma.Methods: We conducted the first genome-wide association study of the age of onset of childhood asthma among participants in the Childhood Asthma Management Program (CAMP) and used 3 independent cohorts from North America, Costa Rica, and Sweden for replication.Results: Two single nucleotide polymorphisms (SNPs) were associated with earlier onset of asthma in the combined analysis of CAMP and the replication cohorts: rs9815663 (Fisher P = 2.31 × 10−8) and rs7927044 (P = 6.54 × 10−9). Of these 2 SNPs, rs9815663 was also significantly associated with earlier asthma onset in an analysis including only the replication cohorts. Ten SNPs in linkage disequilibrium with rs9815663 were also associated with earlier asthma onset (2.24 × 10−7 < P < 8.22 × 10−6). Having 1 or more risk alleles of the 2 SNPs of interest (rs9815663 and rs7927044) was associated with lower lung function and higher asthma medication use during 4 years of follow-up in CAMP.Conclusions: We have identified 2 SNPs associated with earlier onset of childhood asthma in 4 independent cohorts.

Ascaris sensitization is associated with aeroallergen sensitization and airway hyperresponsiveness but not allergic disease in urban Africa - Corrected Proof

Michael Levin, Rudzani Muloiwa, Peter Le Souëf, Cassim Motala — 2012-05-04

Conflicting reports have been published on the association between ascaris sensitization and sensitization to aeroallergens, airway hyperresponsiveness (AHR), and allergic diseases such as asthma, rhinitis, and eczema. We report on the relationship between ascaris-specific IgE and IgE sensitization to aeroallergens, AHR, and allergic diseases in a previously described cohort of black African subjects living in a periurban environment in which both worms and atopy abound.

In moderate-to-severe asthma patients monitoring exhaled nitric oxide during exacerbation is not a good predictor of spirometric response to oral corticosteroid - Corrected Proof

2012-05-04

Background: The importance of monitoring exhaled nitric oxide (NO) in asthma remains controversial.Objective: To measure exhaled NO, postnebulized albuterol/ipratropium spirometry, and Asthma Control Test (ACT) during asthma exacerbation requiring 8- to 10-day tapering oral corticosteroid in nonsmoking patients with moderate-to-severe asthma on moderate-dose inhaled corticosteroid and long-acting β2-agonist but not maintenance oral corticosteroid.Methods: After measuring the fraction of exhaled NO (Feno [ppb]) at 50, 100, 150, and 200 mL/s, the total Feno at 50 mL/s (ppb), large central airway NO flux (J′awNO [nL/s]), and peripheral small airway/alveolar NO concentration (CANO [ppb]) were calculated and corrected for NO axial back-diffusion. Outpatient exacerbation required the patient with asthma to be afebrile with normal chest x-ray and white blood cell count.Results: Group 1 included 17 patients (6 men) with asthma, age 52 ± 12 years, studied at baseline, during 18 exacerbations with abnormal Feno at 50 mL/s, J′awNO, and/or CANO, and post 8- to 10-day tapering 40 mg prednisone (recovery). Baseline: IgE, 332 ± 243 Kμ; total blood eosinophils, 304 ± 266 cells/μL; body mass index, 28 ± 6; ACT, 16 to 19; and FEV1, 2.5 ± 0.7 L (86% ± 20% predicted); exacerbation: FEV1, 1.7 ± 0.4 L (60% ± 17%) (P < .001); recovery: FEV1, 2.5 ± 0.7 L (85% ± 13%) (P < .001). Group 2 included 11 (7 men) similarly treated patients with asthma, age 49 ± 14 years, studied at baseline, during 15 exacerbations with normal Feno at 50 mL/s, J′awNO, and CANO. Baseline: IgE, 307 ± 133 Kμ; total blood eosinophils, 296 ± 149 cells/μL; body mass index, 28 ± 6; ACT, 16 to 19; and FEV1, 2.7 ± 0.9 L (71% ± 12% predicted); exacerbation: FEV1, 1.7 ± 0.6 L (54% ± 19%) (P < .006); recovery: FEV1, 2.7 ± 0.9 L (70% ± 14%) (P = .002). On comparing group 1 versus group 2, there was no significant difference for baseline IgE, eosinophils, body mass index, and ACT and similar significant (≤.006) decrease from baseline in FEV1 (L) during exacerbation and similar increase (≤.006) at recovery.Conclusions: Increased versus normal exhaled NO during outpatient exacerbation in patients with moderate-to-severe asthma on inhaled corticosteroid and long-acting β2-agonist but not maintenance oral corticosteroid does not preclude a robust clinical and spirometric response to tapering oral prednisone.

The IL6R variation Asp358Ala is a potential modifier of lung function in subjects with asthma - Corrected Proof

2012-05-03

Background: The IL6R single nucleotide polymorphism (SNP) rs4129267 has recently been identified as an asthma susceptibility locus in subjects of European ancestry but has not been characterized with respect to asthma severity. The SNP rs4129267 is in linkage disequilibrium (r2 = 1) with the IL6R coding SNP rs2228145 (Asp358Ala). This IL6R coding change increases IL-6 receptor (IL-6R) shedding and promotes IL-6 transsignaling.Objectives: We sought to evaluate the IL6R SNP rs2228145 with respect to asthma severity phenotypes.Methods: The IL6R SNP rs2228145 was evaluated in subjects of European ancestry with asthma from the Severe Asthma Research Program (SARP). Lung function associations were replicated in the Collaborative Study on the Genetics of Asthma (CSGA) cohort. Serum soluble IL-6R levels were measured in subjects from SARP. Immunohistochemistry was used to qualitatively evaluate IL-6R protein expression in bronchoalveolar lavage cells and endobronchial biopsies.Results: The minor C allele of IL6R SNP rs2228145 was associated with a lower percent predicted FEV1 in the SARP cohort (P = .005), the CSGA cohort (P = .008), and in a combined cohort analysis (P = .003). Additional associations with percent predicted forced vital capacity (FVC), FEV1/FVC ratio, and PC20 were observed. The rs2228145 C allele (Ala358) was more frequent in severe asthma phenotypic clusters. Elevated serum soluble IL-6R levels were associated with lower percent predicted FEV1 (P = .02) and lower percent predicted FVC (P = .008) (n = 146). IL-6R protein expression was observed in bronchoalveolar lavage macrophages, airway epithelium, vascular endothelium, and airway smooth muscle.Conclusions: The IL6R coding SNP rs2228145 (Asp358Ala) is a potential modifier of lung function in subjects with asthma and might identify subjects at risk for more severe asthma. IL-6 transsignaling might have a pathogenic role in the lung.

Over- and underestimated parameters in severe Hymenoptera venom–induced anaphylaxis: Cardiovascular medication and absence of urticaria/angioedema - Corrected Proof

Johanna Stoevesandt, Johannes Hain, Andreas Kerstan, Axel Trautmann — 2012-05-03

Background: Severe anaphylaxis in Hymenoptera venom allergy has been associated with a number of risk factors including elevation of baseline serum tryptase (BST), older age, concomitant diseases, and concurrent medication.Objective: The aim of this study was to evaluate indicators and risk factors for severe anaphylaxis due to Hymenoptera field stings with an emphasis on details related to the sting reaction and concurrent medication.Methods: In this single-center observational cohort study, we included 657 consecutive patients fulfilling the criteria for venom immunotherapy. Severity of sting-induced anaphylaxis was analyzed in relation to patient-specific risk factors (age and sex, preexisting cardiopulmonary conditions, cardiovascular medication) and details related to the sting reaction (culprit insect, localization of the sting, time interval to onset of symptoms, and presence or absence of cutaneous involvement). BST was determined in a subgroup of patients with moderate to severe anaphylaxis.Results: Four significant indicators and risk factors of severe anaphylaxis were identified (P < .001): (1) elevation of BST, (2) absence of urticaria or angioedema during anaphylaxis, (3) time interval of less than 5 minutes from sting to onset of symptoms, and (4) senior age. The absence of urticaria/angioedema is significantly related to BST elevation (P = .02). No relationship could be established between the severity of anaphylaxis and comorbidities or concurrent cardiovascular medication.Conclusions: Absence of urticaria/angioedema is an indicator of severe anaphylaxis and possibly mastocytosis, requiring determination of BST. Study data do not provide evidence for an aggravation of sting-induced anaphylaxis by concurrent beta-blockade or angiotensin-converting enzyme inhibition.

Responses to ragweed pollen in a pollen challenge chamber versus seasonal exposure identifies allergic rhinoconjunctivitis endotypes - Corrected Proof

2012-05-03

Background: The level of concordance between allergic symptoms induced on exposure to pollen in a pollen challenge chamber (PCC) versus the natural season is unknown.Objective: We sought to test the hypothesis that the symptom levels of allergic rhinoconjunctivitis elicited after out-of-season exposure to short ragweed in a PCC and during the natural season for giant ragweed pollen are highly correlated.Methods: Thirty-one ragweed-sensitive participants recorded symptoms for 15 days during the natural giant ragweed season in San Antonio, Texas. Twenty-six of these participants were challenged to short ragweed pollen in a PCC for 3 hours per day for up to 4 days.Results: In the PCC participants were dichotomized into those in whom low versus high levels of symptoms developed slowly or rapidly (ie, slow/low vs rapid/high). Each successive exposure visit associated with a progressive increase in symptom levels that approximated those experienced during the natural season. Hierarchic clustering identified 3 endotypes: endotypes I and II reflected concordantly low (n = 7) versus high (n = 14) total symptom scores (TSSs) in both the natural season and the PCC, respectively. Accordingly, the correlation between the TSSs recorded in the natural season and in the PCC for these 21 participants was very high. Although participants with endotype III (n = 5) had greater TSSs in the natural season than in the PCC, the degree of correlation between the TSSs remained high.Conclusions: Our findings affirm our hypothesis, underscore the high cross-reactivity between distinct pollens, and highlight the utility of the PCC to identify novel allergy endotypes that might have contrasting mechanistic underpinnings and potentially therapeutic responses.

TH17 deficiency in human disease - Corrected Proof

Douglas R. McDonald — 2012-05-03

The differentiation of naive T cells into distinct subsets of effector T cells is critical for effective immunity against a wide variety of infectious agents in the environment. Activation of innate immune responses by Candida species through pattern-recognition receptors directs the subsequent development of naive T cells into TH17 cells, which are essential for effective mucosal immunity against fungi. Thorough analyses of cohorts of patients with unusual susceptibility to chronic mucocutaneous candidiasis resulting from TH17 deficiency have confirmed the role of TH17 cells and TH17 cytokines in human host defense against Candida species and have provided valuable insights into the complex process of TH17 cell development.

Oral immunotherapy induces local protective mechanisms in the gastrointestinal mucosa - Corrected Proof

2012-05-03

Background: Oral immunotherapy (OIT) is a promising treatment for food allergy. Studies are needed to elucidate mechanisms of clinical protection and to identify safer and potentially more efficacious methods for desensitizing patients to food allergens.Objective: We established a mouse model of OIT to determine how the dose or form of antigen may affect desensitization and to identify mechanisms of desensitization.Methods: Increasing doses of egg white or ovomucoid as OIT were administered orally to sensitized mice. The impact of OIT on anaphylaxis elicited by oral allergen challenge was determined. Allergen-specific antibody and cytokine responses and mast cell and basophil activation in response to OIT were measured. Gene expression in the small intestine was studied by microarray and real-time PCR.Results: OIT resulted in desensitization but not tolerance of mice to the allergen. OIT did not result in desensitization of systemic effector cells, and protection was localized to the gastrointestinal tract. OIT was associated with significant changes in gene expression in the jejunum, including genes expressed by intestinal epithelial cells. Extensively heated ovomucoid that does not trigger anaphylaxis when given orally to sensitized mice was as efficacious as native ovomucoid in desensitizing mice.Conclusions: OIT results in clinical protection against food-induced anaphylaxis through a novel mechanism that is localized to the intestinal mucosa and is associated with significant changes in small intestinal gene expression. Extensively heating egg allergen decreases allergenicity and increases safety while still retaining the ability to induce effective desensitization.

Aspirin as a cause of pancreatitis in patients with aspirin-exacerbated respiratory disease - Corrected Proof

Donald D. Stevenson, Andrew A. White, Ronald A. Simon — 2012-05-03

Hoyte et al presented 3 cases of acute pancreatitis appearing in patients with aspirin-exacerbated respiratory disease (AERD) who recently underwent aspirin challenge/desensitization. The editors of the Journal of Allergy and Clinical Immunology invited us to review drug-induced pancreatitis and to comment on these cases.

Allergic airway disease is unaffected by the absence of IL-4Rα–dependent alternatively activated macrophages - Corrected Proof

2012-05-02

Background: Markers of alternatively activated macrophages (AAMs) are upregulated in the lungs of asthmatic patients and in mice with allergic airway disease. AAMs are thought to contribute to the pathogenesis of allergic airway disease by virtue of their decreased NO production and increased production of proline and polyamines, which are important in the synthesis of connective tissues such as collagen.Objective: We aimed to define the role of AAMs in the pathogenesis of allergic airway disease.Methods: The IL-4 receptor alpha (IL-4Rα) gene is genetically abrogated in macrophages in LysMcreIL-4Rα−/lox mice, which therefore have impaired IL-4/IL-13 activation of AAMs through IL-4R types 1 and 2. Responses of LysMcreIL-4Rα−/lox mice and IL-4Rα−/lox littermate controls were examined in ovalbumin- and house dust mite–induced allergic airway disease.Results: IL-4Rα expression was shown to be efficiently depleted from alveolar macrophages, interstitial macrophages, and CD11b+MHCII+ inflammatory macrophages. Although the expression of markers of AAMs such as Ym-1, arginase and found in inflammatory zone 1 was decreased in macrophages of LysMcreIL-4Rα−/lox mice in chronic ovalbumin-induced allergic airway disease, airway hyperreactivity, TH2 responses, mucus hypersecretion, eosinophil infiltration, and collagen deposition were not significantly reduced. LysMcreIL-4Rα−/lox mice and littermate controls also developed similar responses in acute ovalbumin- and house dust mite–induced allergic airway disease.Conclusion: Our results suggest that the presence of AAMs in allergic airway disease may be only an association, as a result of the increased TH2 responses present during disease, and that IL-4Rα–dependent AAMs do not play an important role in the pathology of disease.

Effect of secondhand smoke on asthma control among black and Latino children - Corrected Proof

2012-05-02

Background: Among patients with asthma, the clinical effect and relative contribution of maternal smoking during pregnancy (in utero smoking) and current secondhand smoke (SHS) exposure on asthma control is poorly documented, and there is a paucity of research involving minority populations.Objectives: We sought to examine the association between poor asthma control and in utero smoking and current SHS exposure among Latino and black children with asthma.Methods: We performed a case-only analysis of 2 multicenter case-control studies conducted from 2008-2010 with similar protocols. We recruited 2481 Latino and black subjects with asthma (ages 8-17 years) from the mainland United States and Puerto Rico. Ordinal logistic regression was used to estimate the effect of in utero smoking and current SHS exposures on National Heart, Lung, and Blood Institute–defined asthma control.Results: Poor asthma control among children 8 to 17 years of age was independently associated with in utero smoking (odds ratio [OR], 1.5; 95% CI, 1.1-2.0). In utero smoking through the mother was also associated with secondary asthma outcomes, including early-onset asthma (OR, 1.7; 95% CI, 1.1-2.4), daytime symptoms (OR, 1.6; 95% CI, 1.1-2.1), and asthma-related limitation of activities (OR, 1.6; 95% CI, 1.2-2.2).Conclusions: Maternal smoking while in utero is associated with poor asthma control in black and Latino subjects assessed at 8-17 years of age.

Accurate oral food challenge requires a cumulative dose on a subsequent day - Corrected Proof

2012-05-02

Food allergy remains a major problem, not only in terms of an accurate diagnosis to determine the clinically relevant allergen but also to avoid unnecessary or even harmful elimination diets. Oral food challenges are the gold standard in the diagnostic workup of suspected food-related symptoms. Since we observed that some of our oral food challenges were positive only on the day after a cumulative dose had been given, we aimed to investigate the percentage of this kind of positive reaction. A further end point was whether differences between the various foods would be seen.

Ovomucoids IgE is a better marker than egg white–specific IgE to diagnose boiled egg allergy - Corrected Proof

2012-05-02

The oral food challenge (OFC) is the most reliable method to confirm a primary food allergy diagnosis. However, because of the risk of severe allergic reactions during the OFC, physicians are interested in a noninvasive predictor of the outcome. Sampson and Ho and Komata et al have reported predicting OFC outcomes on the basis of specific IgE (sIgE) titers.

Inhibitory human antichimeric antibodies to rituximab in a patient with pemphigus - Corrected Proof

Luisa Lunardon, Aimee S. Payne — 2012-04-30

Rituximab is a chimeric mouse-human IgG1 mAb that targets CD20, a transmembrane protein expressed on B cells. It has demonstrated success in 2 prospective case series in pemphigus, a potentially fatal blistering disease caused by autoantibodies to desmoglein skin adhesion proteins. The production of human antichimeric antibodies (HACAs) to the murine fragments of rituximab has previously been described in pemphigus and other autoimmune disease patients, although a direct functional effect of these HACAs has not been reported. Here we describe a pemphigus patient treated with rituximab who developed inhibitory IgG HACAs associated with infusion reactions and lack of therapeutic response (ie, complete or partial remission of disease).

Comparative dietary therapy effectiveness in remission of pediatric eosinophilic esophagitis - Corrected Proof

2012-04-30

Background: Eosinophilic esophagitis is a chronic, immune-mediated inflammatory disorder that responds to dietary therapy; however, data evaluating the effectiveness of dietary therapeutic strategies are limited.Objective: This study compared the effectiveness of 3 frequently prescribed dietary therapies (elemental, 6-food elimination, and skin prick and atopy patch–directed elimination diets) and assessed the remission predictability of skin tests and their utility in directing dietary planning.Methods: A retrospective cohort of proton-pump inhibitor–unresponsive, non–glucocorticoid-treated patients with eosinophilic esophagitis who had 2 consecutive endoscopic biopsy specimens associated with dietary intervention was identified. Biopsy histology and remissions (<15 eosinophils/high-power field) after dietary therapy and food reintroductions were evaluated.Results: Ninety-eight of 513 patients met the eligibility criteria. Of these 98 patients, 50% (n = 49), 27% (n = 26), and 23% (n = 23) received elemental, 6-food elimination, and directed diets, respectively. Remission occurred in 96%, 81%, and 65% of patients on elemental, 6-food elimination, and directed diets, respectively. The odds of postdiet remission versus nonremission were 5.6-fold higher (P = .05) on elemental versus 6-food elimination diets and 12.5-fold higher (P = .003) on elemental versus directed diets and were not significantly different (P = .22) on 6-food elimination versus directed diets. After 116 single-food reintroductions, the negative predictive value of skin testing for remission was 40% to 67% (milk, 40%; egg, 56%; soy, 64%; and wheat, 67%).Conclusion: All 3 dietary therapies are effective; however, an elemental diet is superior at inducing histologic remission compared with 6-food elimination and skin test–directed diets. Notably, an empiric 6-food elimination diet is as effective as a skin test–directed diet. The negative predictive values of foods most commonly reintroduced in single-food challenges are not sufficient to support the development of dietary advancement plans solely based on skin test results.

A self-regulation intervention can improve quality of life for families with food allergy - Corrected Proof

2012-04-30

Food allergy (FA) affects 3.9% to 8% of children. Children with FA and families have a lower quality of life (QoL) and might have maladaptive coping strategies. Such psychological aspects of living with children with FA are overlooked in traditional FA education, which instead focuses on anaphylaxis management and avoidance measures. Our group has extensive experience with interventions using the theory of self-regulation that can improve QoL in families with chronic illness. Self-regulation states that a crucial element for health-related behavioral change is engagement of the patient. Self-regulation boosts one's confidence toward completing a specific activity through observational and active learning to promote sequential steps of targeted behavioral changes. A self-regulation education model allows parents to (1) acknowledge their concern, (2) discuss the likelihood the concern might occur and critically appraise potential barriers, and (3) contemplate a coping mechanism.

IL-4 receptor polymorphisms predict reduction in asthma exacerbations during response to an anti–IL-4 receptor α antagonist - Corrected Proof

2012-04-30

Background: This is the first large pharmacogenetic investigation of the inflammatory IL-4/IL-13 pathway in patients with moderate-to-severe asthma. We analyzed genomic DNA from participants in a 12-week placebo-controlled efficacy trial of pitrakinra (1, 3, or 10 mg twice daily), a novel IL-4/IL-13 pathway antagonist (Clinicaltrials.gov NCT00801853).Objectives: The primary hypothesis for this analysis is that amino acid changes in the 3′ end of the IL-4 receptor α gene (IL4RA) or closely proximal variants would predict reductions in asthma exacerbations for subjects randomized to pitrakinra therapy.Methods: Nineteen IL4RA single nucleotide polymorphisms (SNPs) were tested in 407 non-Hispanic white subjects for association with the primary clinical end point of asthma exacerbations and changes in secondary end points for asthma symptom scores.Results: The most consistent pharmacogenetic associations were observed for the correlated tagging SNPs rs8832 and rs1029489 in the IL4RA 3′ untranslated and proximal regions, respectively. Subjects homozygous for the rs8832 common G allele randomized to pitrakinra (placebo group nonsignificant) had decreased asthma exacerbations and decreased nocturnal awakenings and activities limited by asthma. There was also a significant pitrakinra dose-response relationship (placebo/1 mg/3 mg/10 mg) for exacerbations in subjects homozygous for the common allele in rs1029489 (P = .005) and rs8832 (P = .009) and the intronic SNPs rs3024585, rs3024622, and rs4787956 (P = .03).Conclusion: This study demonstrates a significant pharmacogenetic interaction between anti–IL-4 receptor α therapy and IL4RA gene variation, identifying an asthma subgroup that is more responsive to therapy with this antagonist.

Molecular mimicry between cockroach and helminth glutathione S-transferases promotes cross-reactivity and cross-sensitization - Corrected Proof

2012-04-27

Background: The extensive similarities between helminth proteins and allergens are thought to contribute to helminth-driven allergic sensitization.Objective: The objective of this study was to investigate the cross-reactivity between a major glutathione-S transferase allergen of cockroach (Bla g 5) and the glutathione-S transferase of Wuchereria bancrofti (WbGST), a major lymphatic filarial pathogen of humans.Methods: We compared the molecular and structural similarities between Bla g 5 and WbGST by in silico analysis and by linear epitope mapping. The levels of IgE, IgG, and IgG4 antibodies were measured in filarial-infected and filarial-uninfected patients. Mice were infected with Heligmosomoides bakeri, and their skin was tested for cross-reactive allergic responses.Results: These 2 proteins are 30% identical at the amino acid level with remarkable similarity in the N-terminal region and overall structural conservation based on predicted 3-dimensional models. Filarial infection was associated with IgE, IgG, and IgG4 anti–Bla g 5 antibody production, with a significant correlation between antibodies (irrespective of isotype) to Bla g 5 and WbGST (P < .0003). Preincubation of sera from cockroach-allergic subjects with WbGST partially depleted (by 50%-70%) anti–Bla g 5 IgE, IgG, and IgG4 antibodies. IgE epitope mapping of Bla g 5 revealed that 2 linear N-terminal epitopes are highly conserved in WbGST corresponding to Bla g 5 peptides partially involved in the inhibition of WbGST binding. Finally, mice infected with H bakeri developed anti-HbGST IgE and showed immediate-type skin test reactivity to Bla g 5.Conclusion: These data demonstrate that helminth glutathione-S transferase and the aeroallergen Bla g 5 share epitopes that can induce allergic cross-sensitization.

Amplification of Toll-like receptor–mediated signaling through spleen tyrosine kinase in human B-cell activation - Corrected Proof

2012-04-27

Background: B cells are activated by combined signals through the B-cell receptor (BCR) and CD40. However, the underlying mechanisms by which BCR signals synergize with Toll-like receptor (TLR) signaling in human B cells remain unclear.Objective: We sought to elucidate a role of spleen tyrosine kinase (Syk), a key molecule of BCR signaling, in TLR-mediated activation of human B cells.Methods: Human naive and memory B cells were stimulated with combinations of anti-BCR, soluble CD40 ligand, and CpG. Effects of the Syk inhibitors on several B-cell functions and expression of TLR9, TNF receptor–associated factors (TRAFs), and phospho–nuclear factor κB in B cells were assessed.Results: Activation of BCR synergized with CD40- and TLR9-mediated signals in driving robust proliferation, cell-cycle progression, expression of costimulatory molecules, cytokine production, and immunoglobulin production of human B-cell subsets, especially memory B cells. However, the Syk inhibitors remarkably abrogated these B-cell functions. Notably, after stimulation through all 3 receptors, B-cell subsets induced marked expression of TLR9, TRAF6, and phospho–nuclear factor κB, which was again significantly abrogated by the Syk inhibitors.Conclusion: Syk-mediated BCR signaling is a prerequisite for optimal induction of TLR9 and TRAF6, allowing efficient propagation of TLR9-mediated signaling in memory B cells. These results also underscore the role of Syk in aberrant B-cell activation in patients with autoimmune diseases.

Long-term safety and asthma control measures with a budesonide/formoterol pressurized metered-dose inhaler in African American asthmatic patients: A randomized controlled trial - Corrected Proof

2012-04-27

Background: Information surrounding the long-term safety of combination inhaled corticosteroid/long-acting β2-adrenergic agonist medications in African American asthmatic patients is limited.Objective: We sought to assess safety and asthma control with a budesonide/formoterol pressurized metered-dose inhaler (pMDI) versus budesonide over 1 year in African American patients.Methods: This 52-week, randomized, double-blind, parallel-group, multicenter, phase 3B safety study (NCT00419952) was conducted in 742 self-reported African American patients 12 years or older with moderate-to-severe asthma previously receiving medium- to high-dose inhaled corticosteroids. After 2 weeks using a 320 μg twice-daily budesonide pMDI, patients were randomized 1:1 to 320/9 μg twice-daily budesonide/formoterol pMDI or 320 μg twice-daily budesonide pMDI.Results: Both treatments were well tolerated. Asthma exacerbation incidence and rate (per patient-treatment year) were lower with budesonide/formoterol versus budesonide (incidence, 7.7% vs 14.0% [P = .006]; rate ratio, 0.615 [P = .002]). Time to first asthma exacerbation was longer (P = .018) with budesonide/formoterol versus budesonide. The most common adverse events, regardless of study drug relationship, were headache (9.5% and 7.7%), nasopharyngitis (6.9% and 8.0%), sinusitis (4.0% and 6.3%), and viral upper respiratory tract infection (5.8% and 4.4%) for budesonide/formoterol and budesonide, respectively. Serious adverse events occurred in 12 and 15 patients, respectively; none were considered drug related. No substantial or unexpected patterns of abnormalities were observed in laboratory, electrocardiographic, or Holter monitoring assessments. Hospitalization caused by asthma exacerbation occurred in 0 and 4 patients in the budesonide/formoterol and budesonide groups, respectively. Pulmonary function and asthma control measures generally favored budesonide/formoterol.Conclusions: In this population budesonide/formoterol pMDI was well tolerated over 12 months, with a safety profile similar to that of budesonide; the asthma exacerbation rate was reduced by 38.5% versus budesonide.

Glandular mast cells with distinct phenotype are highly elevated in chronic rhinosinusitis with nasal polyps - Corrected Proof

2012-04-25

Background: Although chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is characterized by TH2 inflammation, the role of mast cells is poorly understood.Objective: The objective of this study was to investigate the presence, localization, and phenotype of mast cells in patients with CRS.Methods: We collected nasal tissue and nasal lavage fluid from patients with CRS and control subjects. We analyzed mRNA for the mast cell proteases tryptase, chymase, and carboxypeptidase A3 by using real-time PCR and measured mast cell protease proteins by using ELISA, immunohistochemistry, and immunofluorescence.Results: Tryptase mRNA was significantly increased in nasal polyps (NPs) from patients with CRSwNP (P < .001) compared with uncinate tissue from patients with CRS or control subjects. Tryptase protein was also elevated in NPs and in nasal lavage fluids from patients with CRSwNP. Immnohistochemistry showed increased numbers of mast cells in epithelium and glands but not within the lamina propria in NPs. The mast cells detected in the epithelium in NPs were characterized by the expression of tryptase and carboxypeptidase A3 but not chymase. Mast cells expressing all the 3 proteases were abundant within the glandular epithelium of NPs but were not found in normal glandular structures.Conclusions: Herein we demonstrated a unique localization of mast cells within the glandular epithelium of NPs and showed that mast cells in NPs have distinct phenotypes that vary by tissue location. Glandular mast cells and the diverse subsets of mast cells detected may contribute to the pathogenesis of CRSwNP.

The effect of montelukast, budesonide alone, and in combination on exercise-induced bronchoconstriction - Corrected Proof

2012-04-25

Current guidelines recommend regular inhaled corticosteroids (ICS) or alternatively cysteinyl leukotriene (CysLT) modifiers for the treatment of asthma. The CysLT pathway has been shown to be important in the pathophysiology of exercise-induced bronchoconstriction (EIB). However, the protection against EIB by CysLT modifiers alone is reported to be between 40% and 50% with considerable between-subject variability. The rate of nonresponders across studies varies between 18% and 40%, highlighting the heterogeneity in the mechanisms underlying EIB. Alternatively, ICS are potent anti-inflammatory agents that are highly effective in asthma, including alleviating EIB but without any notable effect on the CysLT pathway. These 2 agents have been directly compared only in 2 published trials using low- or high-dose ICS and showing conflicting results. There are no data on medium-dose ICS and their combination with CysLT modifiers in EIB. Such information will extend our knowledge on the dose-response effect of ICS and its role in managing EIB.

STAT6 and LRP1 polymorphisms are associated with food allergen sensitization in Mexican children - Corrected Proof

2012-04-25

Food allergy, affecting up to 8% of children in the United States, is most often mediated by allergen-specific IgE antibodies in the blood. Food allergen sensitization is an intermediate phenotype measured by specific IgE blood tests or skin prick tests (SPTs) and used in the diagnosis of food allergy. Despite family history being a risk factor, no genetic variants have been conclusively identified for food sensitization or clinical food allergy. By using the Mexico City Childhood Asthma Study, we examined associations between food sensitization (based on SPTs) and single nucleotide polymorphisms (SNPs) spanning 5 autosomal candidate genes reviewed by Hong et al (CD14 [cluster of differentiation 14], IL10, IL13, SPINK5 [serine peptidase inhibitor, Kazal type 5 isoform], and STAT6 [signal transducer and activator of transcription 6]).

Protection from childhood asthma and allergy in Alpine farm environments—the GABRIEL Advanced Studies - Corrected Proof

2012-04-25

Background: Studies on the association of farm environments with asthma and atopy have repeatedly observed a protective effect of farming. However, no single specific farm-related exposure explaining this protective farm effect has consistently been identified.Objective: We sought to determine distinct farm exposures that account for the protective effect of farming on asthma and atopy.Methods: In rural regions of Austria, Germany, and Switzerland, 79,888 school-aged children answered a recruiting questionnaire (phase I). In phase II a stratified random subsample of 8,419 children answered a detailed questionnaire on farming environment. Blood samples and specific IgE levels were available for 7,682 of these children. A broad asthma definition was used, comprising symptoms, diagnosis, or treatment ever.Results: Children living on a farm were at significantly reduced risk of asthma (adjusted odds ratio [aOR], 0.68; 95% CI, 0.59-0.78; P < .001), hay fever (aOR, 0.43; 95% CI, 0.36-0.52; P < .001), atopic dermatitis (aOR, 0.80; 95% CI, 0.69-0.93; P = .004), and atopic sensitization (aOR, 0.54; 95% CI, 0.48-0.61; P < .001) compared with nonfarm children. Whereas this overall farm effect could be explained by specific exposures to cows, straw, and farm milk for asthma and exposure to fodder storage rooms and manure for atopic dermatitis, the farm effect on hay fever and atopic sensitization could not be completely explained by the questionnaire items themselves or their diversity.Conclusion: A specific type of farm typical for traditional farming (ie, with cows and cultivation) was protective against asthma, hay fever, and atopy. However, whereas the farm effect on asthma could be explained by specific farm characteristics, there is a link still missing for hay fever and atopy.

Promoter polymorphisms in CHI3L1 are associated with asthma - Corrected Proof

2012-04-25

Increased expression of the glycoprotein Chitinase-3-like-1 (CHI3L1) gene has been associated with cancers, autoimmune diseases, and chronic inflammatory conditions such as asthma (reviewed in Coffman). Asthma patients have a strong upregulation of YKL-40, the protein encoded by CHI3L1, in the airway epithelium and alveolar macrophages. The levels of YKL-40 have been shown to be genetically regulated by the single nucleotide polymorphism (SNP) rs4950928; however, the data remain controversial. In a genome-wide association study, CHI3L1 was found to be a susceptibility gene for asthma, bronchial hyperresponsiveness, and reduced lung function. In relation to asthma, the causal SNP was -131 C→G (rs4950928) in the promoter region of CHI3L1. By contrast, the rs4950928 G allele, and not the C allele, was shown to be associated with asthma in Danish.

Imidazoquinoline Toll-like receptor 8 agonists activate human newborn monocytes and dendritic cells through adenosine-refractory and caspase-1–dependent pathways - Corrected Proof

2012-04-23

Background: Newborns have frequent infections and manifest impaired vaccine responses, motivating a search for neonatal vaccine adjuvants. Alum is a neonatal adjuvant but might confer a TH2 bias. Toll-like receptor (TLR) agonists are candidate adjuvants, but human neonatal cord blood monocytes demonstrate impaired TH1-polarizing responses to many TLR agonists caused by plasma adenosine acting through cyclic AMP. TLR8 agonists, including imidazoquinolines (IMQs), such as the small synthetic 3M-002, induce adult-level TNF from neonatal monocytes, but the scope and mechanisms of IMQ-induced activation of neonatal monocytes and monocyte-derived dendritic cells (MoDCs) have not been reported.Objective: We sought to characterize IMQ-induced activation of neonatal monocytes and MoDCs.Methods: Neonatal cord and adult peripheral blood monocytes and MoDCs were cultured in autologous plasma; levels of alum- and TLR agonist–induced cytokines and costimulatory molecules were measured. TLR8 and inflammasome function were assayed by using small interfering RNA and Western blotting/caspase-1 inhibitory peptide, respectively. The ontogeny of TLR8 agonist–induced cytokine responses was defined in rhesus macaque whole blood ex vivo.Results: IMQs were more potent and effective than alum at inducing TNF and IL-1β from monocytes. 3M-002 induced robust TLR pathway transcriptome activation and TH1-polarizing cytokine production in neonatal and adult monocytes and MoDCs, signaling through TLR8 in an adenosine/cyclic AMP–refractory manner. Newborn MoDCs displayed impaired LPS/ATP-induced caspase-1–mediated IL-1β production but robust 3M-002–induced caspase-1–mediated inflammasome activation independent of exogenous ATP. TLR8 IMQs induced robust TNF and IL-1β in whole blood of rhesus macaques at birth and infancy.Conclusions: IMQ TLR8 agonists engage adenosine-refractory TLR8 and inflammasome pathways to induce robust monocyte and MoDC activation and represent promising neonatal adjuvants.

Development of atopic dermatitis according to age of onset and association with early-life exposures - Corrected Proof

2012-04-23

Background: Environmental factors can affect the development of atopic dermatitis, and this was described to be already effective during pregnancy and in early life. An important early postnatal exposure is nutrition, although its association with allergic disease remains unclear.Objective: We sought to determine prospectively whether early postnatal exposures, such as the introduction to complementary food in the first year of life, are associated with the development of atopic dermatitis, taking into account the reverse causality.Methods: One thousand forty-one children who participated in the Protection Against Allergy–Study in Rural Environments birth cohort study were included in the current study. Atopic dermatitis was defined by a doctor's diagnosis reported by the parents of children up to 4 years of age, by questionnaires, and/or by positive SCORAD scores from 1 year of age and according to the age of onset within or after the first year of life. Feeding practices were reported by parents in monthly diaries between the 3rd and 12th months of life.Results: The diversity of introduction of complementary food in the first year of life was associated with a reduction in the risk of having atopic dermatitis with onset after the first year of life (adjusted odds ratio for atopic dermatitis with each additional major food item introduced, 0.76; 95% CI, 0.65-0.88). The introduction of yogurt in the first year of life also reduced the risk for atopic dermatitis (adjusted odds ratio, 0.41; 95% CI, 0.23-0.73).Conclusion: As early-life exposure, the introduction of yogurt and the diversity of food introduced in the first year of life might have a protective effect against atopic dermatitis.

The public health benefits of air pollution control - Corrected Proof

Jinghong Li, Gary Ewart, Monica Kraft, Patricia W. Finn — 2012-04-23

The US Congress is currently engaged in a debate regarding restriction of Environmental Protection Agency (EPA) authority under the Clean Air Act. The discussion has been focused on the cost to business to comply with the Clean Air Act and the potential negative effect on employment. As heath care professionals, we believe it is necessary to review some of the facts since the Clean Air Act was initiated and the role of the Clean Air Act in the future.

TH2 cytokines increase kallikrein 7 expression and function in patients with atopic dermatitis - Corrected Proof

2012-04-23

Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disorder characterized by a TH2 environment and epidermal barrier dysfunction. A primary defect in the epidermal barrier has been proposed as the initial event in the development of AD because loss-of-function mutations in the filaggrin gene are associated with AD. Excessive protease activity is another characteristic abnormality affecting the epidermal barrier in patients with AD. Human tissue kallikreins (KLKs) are secreted serine proteases encoded by 15 genes located on chromosome 19, and in the skin KLK5 and KLK7 are known as major serine proteases. These proteases degrade corneodesmosome proteins, such as desmoglein 1, desmocollin 1, and corneodesmosin, leading to desquamation. KLK8 and KLK14 also have been shown to be involved in skin desquamation. Although KLK5, KLK8, and KLK14, trypsin-like serine proteases, cleave the carboxyl side of arginine or lysine, KLK7, a chymotrypsin-like serine protease, cleaves the carboxyl side of tyrosine or phenylalanine. An increase in KLK expression has been reported in the epidermis in patients with AD, and the increase in KLK7 expression is prominent among KLKs. An association between genetic variations of KLK7 and AD have been also reported. Patients with Netherton syndrome who have a defect in lymphoepithelial Kazal-type related inhibitor (LEKTI), a serine protease inhibitor that could control excessive KLK activity, have AD-like lesions. Correspondently, the overexpression of human KLK7 in murine epidermis results in chronic itchy dermatitis, which is similar to that seen in patients with chronic AD. These findings suggest that an increase in KLK7 expression is involved in AD pathogenesis, although the regulation of KLK expression in patients with AD has not been fully studied.

Local allergic rhinitis: Concept, pathophysiology, and management - Corrected Proof

2012-04-20

Local allergic rhinitis (LAR) is a localized nasal allergic response in the absence of systemic atopy characterized by local production of specific IgE (sIgE) antibodies, a TH2 pattern of mucosal cell infiltration during natural exposure to aeroallergens, and a positive nasal allergen provocation test response with release of inflammatory mediators (tryptase and eosinophil cationic protein). Although the prevalence remains to be established, a number of patients previously given a diagnosis of nonallergic rhinitis or idiopathic rhinitis are now being classified as having LAR. Culprit allergens responsible include house dust mite, grass and olive pollens, and many others. For the diagnosis of LAR, neither skin prick testing nor determination of the presence of serum sIgE antibodies is useful, and a nasal allergen provocation test is needed to identify the culprit allergen or allergens. In a certain proportion of cases, local sIgE can be detected, and conjunctivitis, asthma, or both can be associated. Whether patients with LAR will have systemic atopy in the future is a matter of debate. Further studies are needed for examine the prevalence of this phenomenon in different areas, to improve the diagnostic methods to better identify these patients, and to develop therapeutic approaches, including the use of immunotherapy.

Amish children living in Northern Indiana have a very low prevalence of allergic sensitization - Corrected Proof

2012-04-19

The prevalence of allergic sensitization has increased in most developed counties over the past century. In the United States, the third National Health and Nutrition Examination Survey found 54.3% of the study population to have evidence of allergic sensitization. European studies have shown similar findings. In contrast to these studies of increasing prevalence, there are now a number of studies demonstrating that certain populations have a significantly lower prevalence of allergic sensitization and a lower prevalence of asthma. Children who reside on traditional Swiss farms are among those with a low prevalence of allergic sensitization.

Does diversity of environmental microbial exposure matter for the occurrence of allergy and asthma? - Corrected Proof

Dick Heederik, Erika von Mutius — 2012-04-16

This review describes the recent literature on microbial exposures and protective effects for asthma and atopy. Certain microorganism-associated molecular patterns have been identified as agents that might influence the development of the immune system, which in turn leads to protective effects for asthma and atopy. Endotoxins from gram-negative bacteria were the first agents associated with a reduced risk for asthma and atopy. In later studies, β(1→3)glucans, extracellular polysaccharides, and muramic acid from, respectively, molds and gram-positive bacteria were associated with a reduced risk of allergy and asthma separately in rural and urban populations. These results already suggested that not just one but several independent microbial signals from gram-negative and gram-positive bacteria, as well as molds, might play a role in explaining the protective effects. Recently, the diversity of microbial exposure has been associated with such a reduced risk in farmers’ children. Surprisingly, the diversity of both fungal and bacterial exposure seemed to have protective effects. These results open new areas of research and create complex challenges. Methodological issues, such as environmental exposure characterization and assessment and elucidation of potential underlying mechanisms, are discussed because these aspects have a major influence on how microbial diversity can be studied in future studies in relation to protective effects for asthma and atopy.

Tolerance induction with T cell–dependent protein antigens induces regulatory sialylated IgGs - Corrected Proof

2012-04-16

Background: Under inflammatory conditions, T cell–dependent (TD) protein antigens induce proinflammatory T- and B-cell responses. In contrast, tolerance induction by TD antigens without costimulation triggers the development of regulatory T cells. Under both conditions, IgG antibodies are generated, but whether they have different immunoregulatory functions remains elusive.Objective: It was shown recently that proinflammatory or anti-inflammatory effector functions of IgG molecules are determined by different Fc N-linked glycosylation patterns. We sought to examine the Fc glycosylation and anti-inflammatory quality of IgG molecules formed on TD tolerance induction.Methods: We administered chicken ovalbumin (OVA) with or without costimulus to mice and analyzed OVA-reactive IgG Fc glycosylation. The anti-inflammatory function of differentially glycosylated anti-OVA IgGs was further investigated in studies with dendritic cell cultures and in an in vivo model of allergic airway disease. Additionally, we analyzed the Fc glycosylation pattern of birch pollen–reactive serum IgGs after successful allergen-specific immunotherapy in patients.Results: Stimulation with TD antigens under inflammatory conditions induces plasma cells expressing low levels of α2,6-sialyltransferase and producing desialylated IgGs. In contrast, plasma cells induced on tolerance induction did not downregulate α2,6-sialyltransferase expression and secreted immunosuppressive sialylated IgGs that were sufficient to block antigen-specific T- and B-cell responses, dendritic cell maturation, and allergic airway inflammation. Importantly, successful specific immunotherapy in allergic patients also induced sialylated allergen-specific IgGs.Conclusions: Our data show a novel antigen-specific immunoregulatory mechanism mediated by anti-inflammatory sialylated IgGs that are formed on TD tolerance induction. These findings might help to develop novel antigen-specific therapies for the treatment of allergy and autoimmunity.

Case-control admixture mapping in Latino populations enriches for known asthma-associated genes - Corrected Proof

2012-04-16

Background: Polymorphisms in more than 100 genes have been associated with asthma susceptibility, yet much of the heritability remains to be explained. Asthma disproportionately affects different racial and ethnic groups in the United States, suggesting that admixture mapping is a useful strategy to identify novel asthma-associated loci.Objective: We sought to identify novel asthma-associated loci in Latino populations using case-control admixture mapping.Methods: We performed genome-wide admixture mapping by comparing levels of local Native American, European, and African ancestry between children with asthma and nonasthmatic control subjects in Puerto Rican and Mexican populations. Within candidate peaks, we performed allelic tests of association, controlling for differences in local ancestry.Results: Between the 2 populations, we identified a total of 62 admixture mapping peaks at a P value of less than 10−3 that were significantly enriched for previously identified asthma-associated genes (P = .0051). One of the peaks was statistically significant based on 100 permutations in the Mexican sample (6q15); however, it was not significant in Puerto Rican subjects. Another peak was identified at nominal significance in both populations (8q12); however, the association was observed with different ancestries.Conclusion: Case-control admixture mapping is a promising strategy for identifying novel asthma-associated loci in Latino populations and implicates genetic variation at 6q15 and 8q12 regions with asthma susceptibility. This approach might be useful for identifying regions that contribute to both shared and population-specific differences in asthma susceptibility.

Novel severe wheezy young children phenotypes: Boys atopic multiple-trigger and girls nonatopic uncontrolled wheeze - Corrected Proof

2012-04-16

Background: Recurrent wheezing during infancy is a heterogeneous disorder that has been associated with early-onset asthma.Objective: To identify phenotypes of severe recurrent wheezing and therapeutic approaches.Methods: We performed cluster analysis with 20 variables of 551 children with active asthma, younger than 36 months old, and enrolled in the Trousseau Asthma Program.Results: We identified 3 independent clusters of children with wheezing. Cluster 1, mild episodic viral wheeze (n = 327), consisted of children with wheezing related only to colds (71%), mild disease (76%), and mainly normal chest x-ray results. Cluster 2, nonatopic uncontrolled wheeze (n = 157), was characterized by moderate to severe disease (91%), uncontrolled wheezing despite high doses of inhaled corticosteroids (55%), parents with asthma, and increased levels of ferritine. Cluster 3, atopic multiple-trigger wheeze (n = 67), included more children with multiple-trigger wheeze (68%) than did clusters 1 or 2; eczema (75%); a positive result from the Phadiatop Infant test (90%); increased levels of IgE, IgA, and IgG; and abnormal results from chest x-rays. In separate analysis, 1 parameter for boys (increased total level of IgE) and 2 parameters for girls (wheezing severity and increased total level of IgE) properly classified 90% of boys and 83% of girls in the appropriate cluster. Significant associations were found between overcrowding, molds and cockroaches at home, and atopic multiple-trigger wheeze and between day-care attendance and nonatopic uncontrolled wheeze in other parts.Conclusion: We identified different phenotypes of recurrent wheezing in young children by using cluster analysis with usual variables. These phenotypes require confirmation in longer, follow-up studies.

Effects of ultraviolet light on human serum 25-hydroxyvitamin D and systemic immune function - Corrected Proof

2012-04-16

Background: Many immune-mediated diseases are associated with low levels of vitamin D and sunlight. UV light or supplementation with vitamin D can increase regulatory T-cell activity and prevent animal models of autoimmune disease. Increasing population vitamin D levels may therefore alleviate the burden of human immune-mediated disease.Objective: To determine the responses of circulating 25-hydroxyvitamin D [25(OH)D] levels, regulatory T-cell numbers, and immune function to UV light exposure in patients being treated for skin disease.Methods: Twenty-four subjects with skin disease from the North of Scotland were recruited between December and March. At baseline, and after 2 and 4 weeks of narrowband UV light exposure, we measured peripheral blood 25(OH)D level, numbers of regulatory T cells (CD4+CD25hiFoxP3+), and T-cell proliferative and cytokine responses to anti-CD3/CD28 stimulation.Results: Median (interquartile range) narrowband UV-B received during the study was 39.1 (30.9) as standard erythema dose, comparable to a quarter of the median summer sunlight exposure received locally. This increased the 25(OH)D level from a mean ± SD of 34 ± 17 nmol/L to 58 ± 16 nmol/L after 2 weeks and 78 ± 19 nmol/L after 4 weeks. The mean proportion of circulating regulatory T cells increased from 0.5% to 1.6% CD3+ cells, which significantly correlated with the increased 25(OH)D level. UV treatment was also followed by reduced proliferative and IL-10 responses to anti-CD3/CD28 independent of the 25(OH)D level.Conclusion: Narrowband UV light reduces systemic immune responsiveness via the induction of regulatory T cells. Light and 25(OH)D levels may affect particular immune functions independently. The levels of serum 25(OH)D over which these effects are apparent should guide future interventions.

Mast cell TNF receptors regulate responses to Mycoplasma pneumoniae in surfactant protein A (SP-A)−/− mice - Corrected Proof

2012-04-16

Background: Mycoplasma pneumoniae (Mp) frequently colonizes the airways of patients with chronic asthma and likely contributes to asthma exacerbations. We previously reported that mice lacking surfactant protein A (SP-A) have increased airway hyperresponsiveness (AHR) during M pneumoniae infection versus wild-type mice mediated by TNF-α. Mast cells (MCs) have been implicated in AHR in asthma models and produce and respond to TNF-α.Objective: Determine the contribution of MC/TNF interactions to AHR in airways lacking functional SP-A during Mp infection.Methods: Bronchoalveolar lavage fluid was collected from healthy and asthmatic subjects to examine TNF-α levels and M pneumoniae positivity. To determine how SP-A interactions with MCs regulate airway homeostasis, we generated mice lacking both SP-A and MCs (SP-A−/−KitW-sh/W-sh) and infected them with M pneumoniae.Results: Our findings indicate that high TNF-α levels correlate with M pneumoniae positivity in human asthmatic patients and that human SP-A inhibits M pneumoniae–stimulated transcription and release of TNF-α by MCs, implicating a protective role for SP-A. MC numbers increase in M pneumoniae–infected lungs, and airway reactivity is dramatically attenuated when MCs are absent. Using SP-A−/−KitW-sh/W-sh mice engrafted with TNF-α−/− or TNF receptor (TNF-R)−/− MCs, we found that TNF-α activation of MCs through the TNF-R, but not MC-derived TNF-α, leads to augmented AHR during M pneumoniae infection when SP-A is absent. Additionally, M pneumoniae–infected SP-A−/−KitW-sh/W-sh mice engrafted with TNF-α−/− or TNF-R−/− MCs have decreased mucus production compared with that seen in mice engrafted with wild-type MCs, whereas burden was unaffected.Conclusion: Our data highlight a previously unappreciated but vital role for MCs as secondary responders to TNF-α during the host response to pathogen infection.

Patchy eosinophil distributions in an esophagectomy specimen from a patient with eosinophilic esophagitis: Implications for endoscopic biopsy - Corrected Proof

2012-04-16

Eosinophilic esophagitis (EoE) is characterized by patchy infiltration into the esophagus by eosinophils, inflammatory leukocytes not found in the healthy esophagus. The pathologic diagnosis can be difficult because the degree of eosinophil infiltration varies greatly within the esophagus, leading to possible underdiagnosis if the tissue is sampled insufficiently. When clinical suspicion for EoE is high, consensus practice requires sampling at 4 to 5 sites throughout the esophagus. However, five 2 mm biopsy specimens represent less than 0.7% of the 20- to 25-cm-long esophageal mucosa and might result in underdiagnosis of EoE if mucosal eosinophilia is particularly patchy. Here we report the analysis of a unique full circumferential esophagectomy specimen from a patient with known EoE who underwent a partial esophagectomy for a concomitant early-stage esophageal adenocarcinoma. We obtained serial cross-sections of the esophagus and mapped eosinophil density across the entire esophageal epithelium. We performed statistical analysis of the data with a Monte Carlo simulation to predict the number of biopsy specimens required to make a diagnosis of EoE in patients with variable eosinophil densities.

Is cat-keeping the main determinant of new-onset adulthood cat sensitization? - Corrected Proof

2012-04-12

We read with interest the article from Olivieri et al showing that acquiring a cat in adulthood increases the risk of new-onset sensitization to cat allergens. Similar studies had been performed in pediatric populations only so far. Despite this, other limitations to the study should be considered in addition to those already acknowledged by authors, in our opinion.

Reply - Corrected Proof

2012-04-12

We thank Liccardi et al for their comments on our article dealing with new-onset cat sensitization in adults. We maintain that cat-keeping and allowing a cat in the bedroom are the main determinants of indoor cat allergen levels in the general European population, as shown by a previous European Community Respiratory Health Survey (ECRHS) study (reference 10 of our article). Cat allergen levels in the mattress were 200 times higher in cat-keeping homes (geometric mean, 61.4 μg/g; 95% CI, 48.4-77.9) with respect to never cat-keeping homes (geometric mean, 0.29 μg/g; 95% CI, 0.27-0.31). Moreover, log-transformed geometric mean of Fel d 1 was 10 times lower when the cat was not allowed inside the house and 4 to 5 times lower when the cat was not allowed inside the bedroom. Liccardi et al reported similar conclusions in a review.

Methacholine challenge test: Diagnostic characteristics in asthmatic patients receiving controller medications - Corrected Proof

2012-04-02

Background: The methacholine challenge test (MCT) is commonly used to assess airway hyperresponsiveness, but the diagnostic characteristics have not been well studied in asthmatic patients receiving controller medications after the use of high-potency inhaled corticosteroids became common.Objectives: We investigated the ability of the MCT to differentiate participants with a physician's diagnosis of asthma from nonasthmatic participants.Methods: We conducted a cohort-control study in asthmatic participants (n = 126) who were receiving regular controller medications and nonasthmatic control participants (n = 93) to evaluate the sensitivity and specificity of the MCT.Results: The overall sensitivity was 77% and the specificity was 96% with a threshold PC20 (the provocative concentration of methacholine that results in a 20% drop in FEV1) of 8 mg/mL. The sensitivity was significantly lower in white than in African American participants (69% vs 95%, P = .015) and higher in atopic compared with nonatopic (82% vs 52%, P = .005). Increasing the PC20 threshold from 8 to 16 mg/mL did not noticeably improve the performance characteristics of the test. African American race, presence of atopy, and lower percent predicted FEV1 were associated with a positive test result.Conclusions: The utility of the MCT to rule out a diagnosis of asthma depends on racial and atopic characteristics. Clinicians should take into account the reduced sensitivity of the MCT in white and nonatopic asthmatic patients when using this test for the diagnosis of asthma.