Rituximab desensitization in pediatric acute lymphoblastic leukemia with severe anaphylaxis.

INTRODUCTION: Hypersensitivity reactions (HSRs) to rituximab occur during the first infusion in 29% to 40% of patients. Commonly, these hypersensitivity reactions are the result of a release of cytokines, although IgE mediated reactions have also been reported. CASE REPORT: A 7-year-old female patient with diagnosis of CD-20 positive acute lymphoblastic B-cell leukemia was included in a pilot study that consisted of two doses of rituximab treatment in the induction to remission phase by the pediatric hematology service; 30 minutes after the first administration of 300 mg of rituximab the patient started with generalized rash, nausea, vomiting, tachycardia, dyspnea, foreign body sensation in throat, oxygen desaturation until 89% and hypotension; therefore, the infusion of rituximab was suspended, and intramuscular epinephrine was administered as well as intravenous hydrocortisone and chlorphenamine and supplemental oxygen supply with adequate resolution of symptoms. MANAGEMENT & OUTCOME: Intradermal skin testing with rituximab at the concentration 1 mg/ml (dilution 1:10), was positive. Desensitization to rituximab was indicated by our service with 4 bags - 16 steps protocol with an initial concentration dose of 1/1,000 of the total dose. The patient was premedicated 1 hour prior with intravenous chlorphenamine, methylprednisolone and ondansetron. Intravenous prophylactic fluids with normal saline solution were administered during the infusion. The procedure was carried out with close monitoring of vital signs in a course of 6.67 hours, without presenting hypersensitivity reactions. DISCUSSION: HSR to rituximab may be induced by the activation of mast cells and basophils. Desensitization protocols are developed when there is no alternative drug for the underlying condition.

Rapid desensitization to brentuximab vedotin after severe anaphylaxis in the treatment of refractory Hodgkin's lymphoma.

INTRODUCTION: Brentuximab vedotin is a monoclonal antibody drug conjugate used for the treatment of patients with Hodgkin lymphoma. Hypersensitivity reactions to brentuximab vedotin may include cutaneous, cardiovascular, respiratory, gastrointestinal and neurological signs and symptoms. CASE REPORT: We present the case of a 23-year-old Mexican female with stage IV progressive classical nodular sclerosing Hodgkin lymphoma who received multiple previous chemotherapy regimens. Brentuximab vedotin at 1.8 mg/kg (180 mg total dose), for 21-day cycles was indicated. Within 5 min of infusion of the 5th cycle of brentuximab, she developed severe anaphylaxis (hives, angioedema, diaphoresis, tachycardia, dyspnea, hypoxemia and loss of consciousness), which was successfully controlled with epinephrine, steroids and antihistamines.Management and outcome: Intradermal skin test at a concentration of 0.1 mg/ml was positive. Due to the severity of the symptoms and the lack of access to alternative treatments, we performed a desensitization protocol. A total of 180 mg of brentuximab was given in three bag solutions in 12 steps, with an initial concentration dose of 1/100 of the total dose in a course of 5.56 h with no hypersensitivity reactions. DISCUSSION: Severe anaphylaxis has been reported in 1.2% of patients receiving brentuximab vedotin. Patients who are treated by rapid drug desensitization with their first option therapy present a favorable survival rate with better cost-effectiveness in comparison to second-line treatment.