['To examine the association between Fcγ receptor (FcγR) polymorphisms and the development of hypersensitivity reactions to adalimumab in patients with rheumatoid arthritis.', "Sixty-five patients receiving adalimumab were enrolled in the study. Genetic polymorphisms for FcγR3B were genotyped in FCGR3B NA1/2 alleles by real allelic discrimination assay. Clinical information and the occurrence of a hypersensitivity reaction to adalimumab were collected from the patients' charts.", 'A hypersensitivity reaction was observed in 12% of the patients. Clinical information obtained from patients with a reaction and those without were the same. The FCGR3B NA1/NA1, NA1/NA2, and NA2/NA2 alleles were found in 75%, 13%, and 13% of the patients with hypersensitivity reaction, respectively, and in 28%, 42%, and 30% of those without a hypersensitivity reaction, respectively (p\u2009=\u20090.04). Multivariate logistic regression analysis identified only the NA1/NA1 as an independent relevant factor for a hypersensitivity reaction to adalimumab (OR 7.7, p\u2009=\u20090.01).'] Is fcγ receptor 3B polymorphism associated with hypersensitivity reactions to adalimumab in Japanese patients with rheumatoid arthritis?