Impact of Fc gamma-receptor polymorphisms on the response to rituximab treatment in children and adolescents with mature B cell lymphoma/leukemia
Abstract
Recent studies in adult lymphoma patients have indicated a correlation between polymorphisms of Fc gamma-receptors (Fc gamma Rs, encoded by the respective FCGR genes) and the response to rituximab treatment. In vitro, cells expressing Fc gamma RIIIa-158V mediate antibody-dependent cellular cytotoxicity (ADCC) more efficiently than cells expressing Fc gamma RIIIa-158F.
The impact of the FCGR2A-131HR polymorphism is unclear. In this study, the FCGR polymorphisms FCGR3A-158VF and FCGR2A-131HR were analyzed in pediatric patients with mature aggressive B cell non-Hodgkin lymphoma/leukemia (B-NHL).
Pediatric patients received a single dose of rituximab monotherapy. Response was evaluated on day 5 followed by standard chemotherapy for B-NHL.
Among 105 evaluable patients, a response to rituximab was observed in 21 % of those homozygous for Fc gamma RIIa-131RR (5/24) compared to 48 % of patients who were HH and HR Fc gamma RIIa-131 allele carriers (18/34 and 21/47, respectively; p = 0.044). Among patients with the FCGR3A-158 polymorphism, those homozygous for the FF genotype had a significantly favorable rituximab response rate of 59 % (22/37) compared to 32 % in patients who were Fc gamma RIIIa-158VV and Fc gamma RIIIa-VF allele carriers (2/9 and 20/59, respectively; p = 0.022).
A stringent phase II response evaluation of children and adolescents with B-NHL after one dose of rituximab monotherapy showed a significant association between the rituximab response rate and FCGR polymorphisms. These findings support the hypothesis that FCGR polymorphisms represent patient-specific parameters that influence the response to rituximab.