Genetic polymorphisms of manganese superoxide dismutase, NAD(P)H:quinone oxidoreductase, glutathione S-transferase M1 and T1, and the susceptibility to drug-induced liver injury

Background/Aims: Drug metabolizing enzymes may be related to drug-induced liver injury (DILI). Manganese superoxide dismutase (MnSOD), NAD(P)H:quinone oxidoreductase (NQO1), and glutathione S-transferase (GST) are important drug metabolizing enzymes. We aimed to elucidate the relationship between genetic polymorphisms of these enzymes and the susceptibility to DILI. Methods: A total of 115 patients with DILI and 115 drug-, sex-, and age-matched controls were enrolled. Their genetic polymorphisms of MnSOD, NQO1, GSTM1, and GSTT1 were assayed. Results: Sixty-three (54.8%) of DILI patients were incriminated to anti-tuberculosis drugs. Subjects with a mutant C allele (T/C or C/C genotype) of MnSOD had a higher risk of DILI than those with MnSOD T/T genotype, both in overall drugs studied (adjusted OR: 2.44, 95% C.I.: 1.38-4.30, P = 0.002), and in sub-category of anti-tuberculosis drugs (adjusted OR: 2.47, 95% C.I.: 1.13-5.39, P = 0.02). In addition, subjects carrying GSTM1 null genotype had increased risk of anti-tuberculosis DILI (adjusted OR: 2.23, 95% C.I.: 1.07-4.67, P = 0.03). Conclusions: The MnSOD mutant C allele may increase the susceptibility to DILI, and GSTM1 null genotype may be related to anti-tuberculosis drug-induced hepatotoxicity. Determination of the MnSOD and GSTM1 genotypes may help identify patients at high risk for DILI. (c) 2007 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.