Genetic polymorphism of the inhibitory IgG Fc receptor FcgammaRIIb is not associated with clinical outcome in patients with follicular lymphoma treated with rituximab

Leuk Lymphoma. 2009 May;50(5):723-7. doi: 10.1080/10428190902829441.


Polymorphisms of activating FcgammaRIIIa (CD16) and FcgammaRIIa (CD32a) have been found to predict rituximab response, probably because of the relative efficiency of different FcgammaR variants in performing antibody-dependent cellular cytotoxicity. The inhibitory FcgammaRIIb (CD32b) has an opposing effect on effector cells. Here, we examined whether an FcgammaRIIb 232 isoleucine (I)/threonine (T) polymorphism predicts rituximab response in 101 patients with follicular lymphoma. Eighty-four patients were 232 I/I, 15 were 232 I/T and two were 232 T/T. The response rate was similar among the three groups. The 2-year progression free survival (PFS) and median time to progression (TTP) were not different between I/I and I/T groups. The TTP was not determined in T/T group because of small number of patients. The FcgammaRIIIa 158 V/V and FcgammaRIIa 131 H/H genotypes continued to emerge as independent predictors for higher response rate and longer TTP. This study is the first to determine whether inhibitory FcgammaRIIb play a role in rituximab's anti-tumor effect in humans.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Murine-Derived
  • Disease Progression
  • Female
  • Genotype
  • Humans
  • Lymphoma, Follicular / diagnosis
  • Lymphoma, Follicular / drug therapy*
  • Male
  • Middle Aged
  • Pharmacogenetics / methods
  • Polymorphism, Genetic*
  • Predictive Value of Tests*
  • Prognosis
  • Receptors, IgG / genetics*
  • Retrospective Studies
  • Rituximab
  • Treatment Outcome


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Murine-Derived
  • Fc gamma receptor IIB
  • Receptors, IgG
  • Rituximab