title: NAT2 and  CYP2E1 polymorphisms associated with antituberculosis drug-induced hepatotoxicity in Chinese patients.
abstract: 1. The present study investigated the relationship between antituberculosis (anti-TB) drug-induced hepatotoxicity and genetic polymorphisms of two important drug-metabolizing enzymes involved in the metabolism of isoniazid, namely N-acetyltransferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1). 2. A polymerase chain reaction direct sequencing approach was used to detect genetic polymorphisms of the NAT2 and CYP2E1 genes in tuberculosis (TB) patients with (n = 101) or without (n = 107) anti-TB drug-induced hepatotoxicity. Associations between various genetic polymorphisms and anti-TB drug-induced hepatotoxicity were then determined. 3. Patients with NAT2 (282TT , 590AA and 857GA) alleles had an increased susceptibility to anti-TB drug-induced hepatotoxicity. The slow acetylator NAT2 genotypes (especially NAT2*6A/7B and NAT2*6A/6A) were risk factors for hepatotoxicity (odds ratio (OR) 9.57 (P < 0.001) for NAT2*6A/7B; OR 5.24 (P = 0.02) for NAT2*6A/6A). 4. The CYP2E1 genotype per se was not significantly associated with the development of anti-TB drug-induced hepatotoxicity. However, the combination of the CYP2E1 C1/C1 genotype with a slow acetylator NAT2 genotype increased the risk of anti-TB drug-induced hepatotoxicity (OR 5.33; P = 0.003) compared with the combination of a rapid acetylator NAT2 genotype with either a C1/C2 or C2/C2 genotype. 5. Thus, slow acetylators with the NAT2*6A/7B and NAT2*6A/6A genotypes combined with the C1/C1 CYP2E1 genotype may be involved in the pathogenesis of anti-TB drug-induced hepatotoxicity. 6. The present findings may be explained, in part, by changes in the metabolism of the anti-TB drug isoniazid induced via NAT2 and CYP2E1, a metabolic process known to produce hepatotoxic intermediates.
authors.affiliation: Institute of Tuberculosis Research, 309th Hospital of Chinese People's Liberation Army, Beijing, China.
authors.forename: Hui-Ru
authors.initials: HR
authors.lastname: An
authors.forename: Xue-Qiong
authors.initials: XQ
authors.lastname: Wu
authors.forename: Zhong-Yuan
authors.initials: ZY
authors.lastname: Wang
authors.forename: Jun-Xian
authors.initials: JX
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Liang
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000009:adverse effects*; D001191:Arylamine N-Acetyltransferase / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D056486:Chemical and Drug Induced Liver Injury / Q000453:epidemiology / Q000235:genetics*; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D019392:Cytochrome P-450 CYP2E1; D001191:Arylamine N-Acetyltransferase; C478900:NAT2 protein, human