Adverse reactions to azathioprine cannot be predicted by thiopurine S‐methyltransferase genotype in Japanese patients with inflammatory bowel disease

Abstract

The frequency of TPMT gene mutations is low among Japanese IBD patients. The incidence of adverse reactions to AZA was high, even in patients carrying wild-type TPMT. It is concluded that determination of TPMT genotype may not be useful in Japanese IBD patients to predict adverse reactions to AZA.