Hypersensitivity reactions to mAbs: 105 desensitizations in 23 patients, from evaluation to treatment

Evaluation of a patient for desensitization. At the initial evaluation, patients with reactions that were not thought to be amenable to desensitization were excluded. Patients with symptoms suggestive of a Gell and Coombs type I HSR, including pruritus, urticaria, flushing, chest tightness, wheezing, nausea, dizziness, or neuromuscular symptoms, were evaluated by means of skin testing. If skin test results were positive, desensitization was offered. If skin test results were negative, the decision whether to offer desensitization was based on the severity of the initial reaction and clinical judgment.

Management of reactions during desensitization. The infusion was held for all reactions. Severe reactions were treated aggressively, as shown. Histamine H₁ and H₂ blockade was administered for all reactions. For flushing or airway symptoms, specific treatment was initiated, as depicted.

Severity of initial reactions and reactions during desensitization. A, The percentage of patients with mild, moderate, and severe reactions is presented by agent for the initial reaction, with the total number of patients for each agent shown in parentheses after the name of the agent. B, Reactions during desensitization were graded as mild, moderate, severe, or no reaction and are presented as a percentage of total desensitizations for a given agent. The number of desensitizations for each agent is shown in parentheses after the name of the agent.

Characteristics of initial reactions and reactions during desensitization. The characteristics of reactions are depicted by agent for the initial reaction (A) and for reactions during desensitization (B). Data in Fig 4, B, are expressed as percentages of the total desensitizations performed for each agent. CUT, Cutaneous; CV, cardiovascular; RESP, respiratory; THROAT, throat tightness, F/C, fever/chills; GI, gastrointestinal; NEURO, neurologic/muscular.

Timing of reactions during desensitization. The steps at which reactions occurred among 30 reactions during desensitization are shown as a percentage of all reactions. One patient with an extended protocol reacted in the final step, and this reaction was included under step 12.

Reactions over multiple desensitizations. The frequency of reactions at each desensitization number is presented. The number of patients who reached each number of desensitizations is indicated in parentheses.