Purpose: Rituximab has been given after autologous hematopoietic cell transplantation for recurrent or refractory B-cell lymphoma with the goal of eradicating minimal residual disease. Our previous report showed that administration of two courses of rituximab after transplantation is feasible, with encouraging clinical outcomes after a short follow-up. However, neutropenia after the first or second post-transplantation rituximab treatment occurred in 52% of patients. We previously reported that polymorphisms of two immunoglobulin G Fc receptors predict rituximab response, presumably because of their role in antibody-dependent cellular cytotoxicity. In the current report, we determine whether FcgammaR polymorphisms are correlated with clinical outcomes in 33 patients with B-cell non-Hodgkin's lymphoma who received post-transplantation rituximab.
Patients and methods: Genomic DNA was used for FcgammaRIIIa V/F or the FcgammaRIIa H/R genotyping. The FcgammaR polymorphisms were then correlated with the incidence of rituximab-induced neutropenia, event-free survival (EFS), and overall survival (OS).
Results: The FcgammaRIIIa 158 V allele dose was correlated with a higher incidence of rituximab-induced neutropenia. The odds of neutropenia after the first or second post-transplantation rituximab increased three-fold with each V allele (robust z = 2.08, P = .038). The FcgammaRIIa polymorphism had no impact on rituximab-induced neutropenia. We did not observe a correlation of either FcgammaRIIIa or FcgammaRIIa polymorphism with EFS or OS.
Conclusion: The high affinity FcgammaRIIIa 158 V allele is associated with rituximab-induced neutropenia after autologous transplantation. This is a potential tool to identify a high-risk population for developing neutropenia after antibody therapy.