Most cases with antituberculosis drug-induced hepatitis have been attributed to isoniazid. Isoniazid is metabolized by hepatic N-acetyltransferase (NAT) and cytochrome P450 2E1 (CYP2E1) to form hepatotoxins. However, the role of CYP2E1 in this hepatotoxicity has not yet been reported. The aim of this study was to evaluate whether the polymorphism of the CYP2E1 gene is associated with antituberculosis drug-induced hepatitis. A total of 318 tuberculosis patients who received antituberculosis treatment were followed prospectively. Their CYP2E1 and NAT2 genotypes were determined using a polymerase chain reaction with restriction fragment length polymorphism method. Twenty-one healthy volunteers were recruited for CYP2E1 phenotype study using a chlorzoxazone test. Forty-nine (15.4%) patients were diagnosed to have drug-induced hepatotoxicity. Patients with homozygous wild genotype CYP2E1 c1/c1 had a higher risk of hepatotoxicity (20.0%; odds ratio [OR], 2.52) than those with mutant allele c2 (CYP2E1 c1/c2 or c2/c2, 9.0%, P ‫؍‬ .009). 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. After adjustment for acetylator status and age, the CYP2E1 c1/c1 genotype remained an independent risk factor for hepatotoxicity (OR, 2.38; P ‫؍‬ .017). Furthermore, under the administration of isoniazid, the volunteers with CYP2E1 c1/c1 genotype had higher CYP2E1 activity than those with other genotypes had and, hence, might produce more hepatotoxins. In conclusion, CYP 2E1 genetic polymorphism may be associated with susceptibility to antituberculosis drug-induced hepatitis. (HEPATOLOGY 2003;37:924-930.)

Airway inflammation is an important pathologic feature in chronic bronchitis, and we hypothesized that individuals with greater inflammatory responses may be more likely to acquire the disease. A polymorphism at -308 position of the tumor necrosis factor-alpha (TNF-alpha) gene has been described, with the rarer allele, TNF2, demonstrated to have higher inducibility in vitro. We investigated the distribution of this polymorphism in a case-control study. The genotype was determined in 42 male patients with chronic bronchitis, 42 sex-, age-, and smoking index-matched control subjects, and 99 random-sampled schoolchildren. We report here that the TNF2 allele is overrepresented in the patient group. The allele frequency of TNF2 is 5.1% in the schoolchildren, 2.4% in the control group, and 19% in the bronchitis group (p < 0.01). Carriage of the TNF2 allele confers a higher risk to the development of chronic bronchitis (odds ratio = 11.1, 95% CI = 2.89-42.57). The results demonstrate the important pathologic role of TNF-alpha in chronic bronchitis and suggest that greater inflammatory response may predispose an individual to this disease.

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