The impact of Fc gamma receptor IIa and IIIa gene polymorphisms on the therapeutic response of rituximab in Egyptian adult immune thrombocytopenic purpura

ABSTRACTBackground: In chronic immune thrombocytopenic purpura (ITP), rituximab removes the harmful autoantibodies through antibody-dependent cellular cytotoxicity. The response to rituximab in ITP is variable; the effectiveness of rituximab is influenced by the process of activation of effector fragment C gamma receptors (FcγRs). Genetic factors may affect the response to rituximab.Objectives: The influence of FcγRIIa (H131R) and FcγRIIIa (V158F) gene polymorphisms on the response to rituximab in ITP.Methods: One hundred ITP patients were genotyped for FcγRIIa (H131R) and FcγRIIIa (V158F) gene polymorphisms using the polymerase chain reaction-restriction fragment length polymorphism assay. The response at the end of the third month was assessed by direct platelets count. Polymorphisms were analyzed in relation to the response.Results: The mean platelets count at end of weeks 1–4 of rituximab was statistically significantly higher in patients who achieved complete response (CR) than partial response or no...