FcγRIIa polymorphism and clinical response to rituximab in non-Hodgkin lymphoma patients

Rituximab is a chimeric monoclonal antibody that specifically targets the CD20 surface marker expressed in neoplastic B-lymphoid cells. Combined with chemotherapy or alone, in maintenance/consolidation, it is used for the treatment of non-Hodgkin lymphoma (NHL). The role of a polymorphism in a specific Fc gamma receptor gene, FcγRIIa, in the clinical outcome of patients with NHL was investigated in this study. We characterized DNA samples from 64 non-Hodgkin lymphoma patients treated with rituximab using a polymerase chain reaction–restriction fragment length polymorphism method. The FcγRIIa HH genotype was significantly correlated with complete response to rituximab compared to the R allele (P=0.028). In terms of overall or event-free survival, no difference was found according to FcγRIIa alleles. We hypothesize that the HH genotype increases the affinity of the FcγRIIa receptor, not only for naturally occurring IgG2, but also to ameliorate connection with chimeric IgG1 rituximab, contributing to a genetic individual profile of great interest in clinical onco-hematology.