The role of cigarette smoking and liver enzymes polymorphisms in anti-tuberculosis drug-induced hepatotoxicity in Brazilian patients

Summary Tuberculosis (TB) is still a major health concern and side-effects related to the treatment, especially drug-induced hepatotoxicity (DIH), should be better investigated. In the present study, a possible association between anti-TB DIH and cigarette smoking, N-acetyltransferase 2 ( NAT2 ), Cytochrome P450 2E1 ( CYP2E1 ) and Cytochrome P450 3A4 ( CYP3A4 ) genotypes was studied in 131 TB Brazilian patients. The NAT2 and CYP3A4 genetic polymorphisms were determined using a polymerase chain reaction (PCR) direct sequencing approach and genetic polymorphisms of CYP2E1 gene were determined by restriction fragment length polymorphism (RFLP). The risk of anti-TB DIH was lower in rapid/intermediate acetylators when compared to slow acetylators (OR: 0.34, CI 95: 0.16–0.71; p