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


CONCLUSIONS
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.
Department of Medicine, Maulana Azad Medical College, New Delhi, India.
Purabi Deka
PD
Bose
Manash Pratim
MP
Sarma
Subhash
S
Medhi
Bhudev Chandra
BC
Das
Syed Akhtar
SA
Husain
Premashis
P
Kar
D000107:Acetylation; D000328:Adult; D000995:Antitubercular Agents / Q000009:adverse effects*; D001191:Arylamine N-Acetyltransferase / Q000235:genetics* / Q000378:metabolism; D056486:Chemical and Drug Induced Liver Injury / Q000201:enzymology / Q000208:ethnology / Q000235:genetics*; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics* / Q000378:metabolism; D004359:Drug Therapy, Combination; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D007194:India; D007438:Introns; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D016017:Odds Ratio; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
D000995:Antitubercular Agents; D019392:Cytochrome P-450 CYP2E1; D001191:Arylamine N-Acetyltransferase; C478900:NAT2 protein, human