2016, Number 3
Alerg Asma Inmunol Pediatr 2016; 25 (3)
Rituximab desensitization: case report of a pediatric patient on a conditioning regime for stem cell transplant
Esparza-Carrillo D, Rodríguez-González M, Azamar-Jácome AA, Venegas-Montoya E, Falck-Fuentes CA, López-Hernández G, Ramírez-Uribe N, Mendoza-Hernández DA
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ABSTRACTWe present the case of an eight-year-old female girl with the diagnosis of Fanconi’s anemia. The patient is going through the process of a stem cell transplant. The donor in this case is the father; it is a haploidentic, peripheral blood transplant with selective cell depletion with a CD 34+ marker. Donor specific antibodies (DSA) against HLA are positive, so a conditioning protocol with rituximab is prescribed. Thirty minutes after the first rituximab infusion (dose received 50 mg at infusion rate of 100 mL/h) the patient presents with an anaphylactic reaction: sudden onset of wheezing, shortness of breath, prolonged capillary refill, weak pulses and fever. The use of rituximab is considered essential in this patient given the high risk of primary graft failure, so it is decided to use a rapid desensitization protocol as described by Castell and Hong aiming to achieve a transitory tolerance by administering a drug with a previous type 1 hypersensitivity reaction. The procedure is performed under strictly supervised conditions. The infusion is administered in 12 steps, with 3 solutions, each of these with a dilution of 1:100, 1:10 and the usual dilution. The rate of infusion is augmented gradually. Before the infusion the patient is treated with montelukast, acetyl salicylic acid and cloropiramine. The total dose of 375 mg/m2BS/do is administered without hypersensitivity reactions. The patient successfully receives four complete doses of rituximab as prescribed, all of these infusions administered under the same protocol of rapid desensitization. There were no adverse effects nor allergic reactions reported. Conclusion: Monoclonal antibodies are highly effective therapies with a high specifity and affinity for a protein or target molecule. Rituximab is used in desensitization protocols in patients undergoing haploidentic stem cell transplant who are positive for donor specific antibodies anti-HLA, thus reducing the risk of primary graft failure. Rituximab use is limited by the hypersensitivity reactions caused by it, with anaphylaxis being the most serious of them. Using rapid desensitization protocols as described in this case the drug can be administered safely thus eliminating the need to use therapeutic alternatives that could have serious adverse effects or be less effective. Rapid desensitization procedures should be individualized to the clinical presentation of previous reactions and to the existing protocols. These procedures should be performed under expert supervision. This is the first pediatric case reporting successful rituximab desensitization.