[Non-allergic immediate hypersensitivity to Brentuximab vedotin in pediatrics: usefulness of skin testing to guide provocation testing].

Background: Hypersensitivity reactions to monoclonal antibodies represent a clinical challenge, especially when there are no equivalent therapeutic alternatives. Brentuximab vedotin (BV), an anti-CD30 monoclonal antibody indicated for relapsed Hodgkin lymphoma, has been associated with immediate hypersensitivity in 1.2% of cases.

Case report: An 11-year-old patient with relapsed Hodgkin lymphoma presented with grade 3 anaphylaxis (Brown scale) with hypotension, dyspnea, cough, wheezing, bipalpebral edema, conjunctival injection, nausea, and altered consciousness during the fifth cycle of chemotherapy with AVD (doxorubicin, vinblastine, and dacarbazine) + BV. Intramuscular epinephrine and fluid therapy were administered, with resolution of the condition. Laboratory Studies: BV skin tests performed 2 weeks after the event were negative. Outcome: Given the immediacy and severity of the event, and the need to continue treatment, a successful pharmacological challenge with AVD agents was performed. Subsequently, two cycles of BV desensitization were performed (cycles 6 and 7), using different protocols, without adverse reactions.

Conclusion: Although skin tests were negative, the clinical presentation was consistent with immediate non-allergic hypersensitivity. Desensitization allowed treatment to continue with adequate tolerance and without recurrence. Repeat skin tests are currently being considered 4 to 6 weeks after the index event; if negative, a BV challenge test is considered. Skin tests support safety prior to a controlled challenge. Desensitization is an effective strategy for continuing essential treatments in pediatric oncology.