Role of polymorphic N-acetyl transferase2 and cytochrome P4502E1 gene in antituberculosis treatment-induced hepatitis

• Published in: Journal of gastroenterology and hepatology Vol. 26; no. 2; pp. 312 - 318
• Main Authors: Bose, Purabi Deka, Sarma, Manash Pratim, Medhi, Subhash, Das, Bhudev Chandra, Husain, Syed Akhtar, Kar, Premashis
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Asia 01.02.2011; Wiley-Blackwell
• Subjects: Acetylation; acetylator status; Adult; Antitubercular Agents - adverse effects; antituberculosis treatment; Arylamine N-Acetyltransferase - genetics; Arylamine N-Acetyltransferase - metabolism; Biological and medical sciences; Chemical and Drug Induced Liver Injury - enzymology; Chemical and Drug Induced Liver Injury - ethnology; Chemical and Drug Induced Liver Injury - genetics; CYP2E1; CYP2E1 gene; Cytochrome P-450 CYP2E1 - genetics; Cytochrome P-450 CYP2E1 - metabolism; drug induced hepatitis; Drug Therapy, Combination; Drugs; Female; Gastroenterology. Liver. Pancreas. Abdomen; Gene Frequency; Gene polymorphism; Genetic factors; Genetic Predisposition to Disease; Genotyping; Hepatitis; hepatotoxicity; Humans; India; Introns; Isoniazid; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Logistic Models; Lung; Male; Medical sciences; Middle Aged; Mycobacterium; NAT2; Nutritional Status; Odds Ratio; Other diseases. Semiology; Phenotype; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Polymorphism, Single Nucleotide; Population studies; Promoter Regions, Genetic; Rifampin; Risk Assessment; Risk Factors; Time Factors; Tuberculosis; Hepatitis; Treatment; drug induced hepatitis; acetylator status; Enzyme; NAT2; Cytochrome P450; Gastroenterology; Digestive diseases; Hepatic disease; antituberculosis treatment; CYP2E1
• ISSN: 0815-9319; 1440-1746
• DOI: 10.1111/j.1440-1746.2010.06355.x

Background and Aim:  Antituberculosis drugs, isoniazid and rifampicin, in combination, are known to develop drug‐induced hepatotoxicity (DIH). A higher risk of DIH during antituberculosis treatment (ATT) has been reported in the Indian subcontinent compared to its Western counterparts. The role of genetic factors in a higher incidence of ATT hepatotoxicity in the Indian population is still unclear. The present study was aimed at investigating the role of the N‐acetyltransferase2 (NAT2) and cytochrome P4502E1 (CYP2E1) gene polymorphisms in ATT hepatotoxicity. Methods:  The study population included 218 pulmonary tuberculosis patients who were started on ATT and followed up for the occurrence of ATT‐induced hepatitis. The genetic polymorphisms of the NAT2 and CYP2E1 genes were studied by polymerase chain reaction–restriction fragment length polymorphism. Results:  The occurrence of DIH was 18.8% (41/218). There was a higher prevalence of NAT2 slow‐acetylator genotypes in DIH (70.73%) compared to non‐DIH (44.63%; P < 0.05). The frequency of the NAT2*5/*7 and NAT2*6/*7 genotypes was significantly higher in DIH than non‐DIH (19.51% vs 6.78%, and 19.51% vs 5.08%). No association of the CYP2E1 RsaI polymorphism could be demonstrated with DIH. However, the DraI C/D genotype of the CYP2E1 gene was mostly prevalent in DIH (85.37%), compared to non‐DIH (64.41%) (P < 0.05). Slow‐acetylator status and the CYP2E1 C/D or C/C genotype together showed a higher frequency in DIH (65.85%) compared to non‐DIH (28.81%) (P < 0.0001). Conclusion:  The study demonstrates for the first time a possible association between the DraI polymorphism of the CYP2E1 gene and the risk of ATT hepatotoxicity. The genotyping of the NAT2 and CYP2E1 genes could possibly identify the groups at highest risk of developing ATT‐induced hepatitis prior to medication.