Trimethoprim-sulfamethoxazole use is associated with improved lung function in pediatric asthma


      Pneumocystis, an opportunistic fungus, can induce inflammation and airway hyperresponsiveness similar to asthma in preclinical models. In patients with severe asthma, Pneumocystis colonization and immune responsiveness has been previously demonstrated. We sought to determine if pediatric patients with asthma that received trimethoprim-sulfamethoxazole, a hallmark therapy for Pneumocystis, would demonstrate improvement in lung function.


      In a retrospective case-control study design, the electronic medical record of Children’s Hospital of Pittsburgh was queried form 2010-2018 for patients receiving trimethoprim-sulfamethoxazole or clindamycin with one pulmonary function test. Patients were included if a diagnosis of asthma was present at the time of antibiotic exposure. Pulmonary function tests and ED visits for asthma exacerbation were the primary and secondary outcomes, respectively.


      Patients with asthma that received trimethoprim-sulfamethoxazole had improved FEV1 and FVC following treatment when compared to baseline pulmonary function tests. Additionally, patients receiving trimethoprim-sulfamethoxazole had improved lung function compared to the control group receiving clindamycin. Improvement in lung function was seen in patients independent of inhaled corticosteroid dose. Furthermore, trimethoprim-sulfamethoxazole, but not clindamycin, use was associated with a reduced number of emergency department visits for asthma the 12 months following administration.


      This retrospective study temporally associates the use of trimethoprim-sulfamethoxazole with improved lung function and decreased emergency department visits in children with asthma. Together, the current study demonstrates that treatment with trimethoprim-sulfamethoxazole, a standard therapy for Pneumocystis, is associated with improved asthma control. Prospective clinical evaluation of Pneumocystis-centered therapy in patients with asthma is warranted.