Fcγ receptor IIIb polymorphism and use of glucocorticoids at baseline are associated with infusion reactions to infliximab in patients with rheumatoid arthritis

Objective: Infusion reaction is a major adverse event in patients with rheumatoid arthritis (RA) treated with infliximab. The possible factors including Fcγ receptor (FcγR) polymorphism associated with the development of infusion reactions in patients with RA receiving infliximab were prospectively examined. Methods: 96 patients with RA were enrolled and scheduled to receive infliximab at a dose of 3 mg/kg at weeks 0, 2 and 6 and every 8 weeks thereafter. Genetic polymorphisms for FcγR were examined in FCGR3A 176F/V and FCGR3B NA1/2 alleles by allele-specific PCR analysis. Results: An infusion reaction was observed in 17 patients (18%) during 52 weeks of treatment with infliximab. The FCGR3B NA1/NA1 genotype was found in 75% of the patients with infusion reactions and in only 37% of those without (p=0.01), whereas the FCGR3A 176F/V genotype was equally distributed in the patients with or without infusion reactions. Glucocorticoids were used in 53% of the patients who developed an infusion reaction and in 80% of those without an infusion reaction (p=0.02). A multivariable logistic regression model showed that the FCGR3B NA1/NA1 genotype and use of glucocorticoids at baseline could be used as independent predictive factors for infusion reactions (OR 6.1 (95% CI 1.9 to 24.3) and OR 0.26 (95% CI 0.08 to 0.84), respectively). The presence of anti-infliximab antibody during infliximab treatment was also associated with infusion reactions. Conclusion: FCGR3B NA1/NA1 genotype, use of glucocorticoids and the presence of anti-infliximab antibody accounted for nearly all patients with RA who developed infusion reactions.