The risk of ATDILI was significantly increased with the following genotypes: <i>CYP2E1 Rsa</i>I<i>/Pst</i>I c1/c1 (OR=1.39, 95% CI 1.06 to 1.83), <i>NAT2</i> slow acetylator (OR=3.30, 95% CI 2.65 to 4.11) and <i>GSTM1</i> null (OR=1.30, 95% CI 1.12 to 1.52).
This study suggests that the slow acetylator profile [odds ratio (OR): 3.02; 95% confidence interval (CI): 1.82-5.00; P<0.001], genotypes carrying the c2 variant (OR: 2.16; 95% CI: 1.33-3.51; P=0.002) or the A4 variant of CYP2E1 (OR: 2.13; 95% CI: 1.06-4.29; P=0.050), and female sex (OR: 1.94; 95% CI: 1.20-3.14; P=0.006) were independent predictor variables for ATDH.
Our results suggest that a serum concentration of isoniazid over 3.69 mg l<sup>-1</sup> and a combined genotype CYP2E1 DraI(C/D)/slow acetylator are major risk factors for IIH.
If CYP2E1 c1/c2 or c2/c2 genotype combined with rapid acetylator status was regarded as the reference group, the risk of hepatotoxicity increased from 3.94 for CYP2E1 c1/c1 with rapid acetylator status to 7.43 for CYP2E1 c1/c1 with slow acetylator status.