Association of N-acetyltransferase 2 and cytochrome P450 2E1 gene polymorphisms with antituberculosis drug-induced hepatotoxicity in Western India
Version of Record online: 22 JUL 2013
© 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd
Journal of Gastroenterology and Hepatology
Volume 28, Issue 8, pages 1368–1374, August 2013
How to Cite
Gupta, V. H., Amarapurkar, D. N., Singh, M., Sasi, P., Joshi, J. M., Baijal, R., Ramegowda, P. H., Amarapurkar, A. D., Joshi, K. and Wangikar, P. P. (2013), Association of N-acetyltransferase 2 and cytochrome P450 2E1 gene polymorphisms with antituberculosis drug-induced hepatotoxicity in Western India. Journal of Gastroenterology and Hepatology, 28: 1368–1374. doi: 10.1111/jgh.12194
- Issue online: 22 JUL 2013
- Version of Record online: 22 JUL 2013
- Accepted manuscript online: 11 MAR 2013 08:54PM EST
- Manuscript Accepted: 27 FEB 2013
- Department of Science and Technology, Ministry of Science and Technology, Government of India. Grant Number: SR/S3/CE/11/2005
- drug-induced hepatotoxicity;
- genetic polymorphisms;
- slow acetylator;
- TB patients
Background and Aim
Tuberculosis (TB) is a major public health problem in India. Despite the treatment availability and monitoring, drug-induced hepatotoxicity (DIH) is a serious concern and can lead to discontinuation of treatment. Anti-TB DIH is well known and can aggravate because of pharmacokinetic and pharmacodynamic interactions. Genetic polymorphism in the drug-metabolizing enzyme genes is an important factor that predisposes certain fraction of the population to drug-induced toxicity. The purpose of this study was to assess the association of N-acetyltransferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1) gene polymorphism with anti-TB DIH in Western Indian population.
A prospective cohort study of 215 patients taking treatment against TB was performed. The NAT2 and CYP2E1 genotypes were determined using polymerase chain reaction and restriction fragment length polymorphism methods. Logistic regression model was used to calculate odds ratio at 95% confidence interval and their respective P values.
The risk of anti-TB DIH was significantly higher in slow acetylator (SA) than in intermediate and rapid acetylator of NAT2 genotypes (odds ratio: 2.3, P = 0.01). We also observed the homozygous point mutation at position 481, associated with higher risk of hepatotoxicity (P < 0.01). The major haplotype NAT2*4 seems to provide protection in DIH compared with non-DIH TB patients (P = 0.04). However, we did not find a significant association between CYP2E1 genotypes and anti-TB DIH.
Increased susceptibility to isoniazid (INH)-induced hepatotoxicity due to presence of NAT2 SA polymorphism was demonstrated in Western Indian population. NAT2 genotyping can therefore serve as an important tool for identifying patients predisposed to anti-TB DIH.