Glutathione S-Transferase M1 and T1 Gene Polymorphisms and the Outcome of Chronic Hepatitis C Virus Infection in Egyptian Patients

Association of Polymorphisms in the Glutathione S-Transferase Theta-1 Gene with Cirrhosis and Hepatocellular Carcinoma in Brazilian Patients with Chronic Hepatitis C

Oxidative stress contributes to hepatitis C virus (HCV)–induced liver damage. Host genetic factors may be involved in progression of HCV infection. The present study was conducted to determine the influence of glutathione S-transferase (GST)-M1 and T1 gene polymorphisms during different stages of HCV infection, including chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The study population comprised 190 patients (47 with chronic hepatitis, 83 with cirrhosis (without HCC), and 60 with HCC). GSTM1 and GSTT1 gene polymorphisms were analyzed via multiplex polymerase chain reaction. The GSTT1-null genotype was more commonly detected in patients with cirrhosis (n = 17; 20.5%) and HCC (n = 13; 21.7%) than those with chronic hepatitis (n = 3; 6.4%). The differences in GSTT1-null genotype frequencies were significant for cirrhosis vs. chronic hepatitis (odds ratio, OR, 3.778 (95% confidence interval, CI, 1.045–13.659); p = 0.043) and HCC vs. chronic hepatitis (OR, 4.057 (95% CI, 1.083–15.201); p = 0.038) groups. However, the incidence of individual GSTM1-null or combined GSTM1/GSTT1 double-null genotypes did not vary significantly between the groups. Our collective findings support the utility of the GSTT1-null genotype as a useful biomarker for liver disease progression in Brazilian patients with chronic hepatitis C.

Polymorphism of Glutathione S-transferase Genes and the Risk of Toxic Liver Damage in Petrochemical Workers

BACKGROUND

Exposure to numerous chemicals, including industrial ones, may result in liver damage. The body susceptibility to the environmental hazards largely depends on the activity of the enzymes in the xenobiotic detoxification system. Function abnormalities of such enzymes due to genetic variations would increase the risk of developing various diseases.

OBJECTIVE

To elucidate the relationship between polymorphism in glutathione S-transferase genes (GSTM1, GSTT1 and GSTP1) and the risk of toxic liver damage in a group of petrochemical workers.

METHODS

This study was conducted on 72 workers with toxic liver injury, 156 healthy workers, and 322 healthy individuals without history of occupational exposure to chemicals. Genotyping of the GSTP1 rs1695 gene polymorphism was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Polymerase chain reaction (PCR) was used to perform genotyping of the GSTM1 and GSTT1 genes polymorphism.

RESULTS

There was a significant difference in genotype frequencies of the GSTP1 rs1695 gene polymorphism among the groups studied. The distribution of Val/Val genotype of the GSTP1 rs1695 gene polymorphism had a higher incidence in healthy workers compared with patients with toxic liver damage (p=0.036). No significant association was found between the GSTM1 and GSTT1 polymorphisms and toxic liver damage.

CONCLUSION

The GSTP1 rs1695 gene polymorphism can play a protective role in the development of toxic liver damage in petrochemical workers.

The influence of polymorphic GSTM1 gene on the increased susceptibility of non-viral hepatic cirrhosis: evidence from observational studies

It is reported that glutathione S-transferase mu (GSTM1) polymorphism is associated with non-viral hepatic cirrhosis (HC). However, some studies showed different views. Therefore, in this paper, a meta-analysis was conducted to get a more comprehensive understanding of GSTM1 polymorphisms in non-viral HC susceptibility. The results showed that GSTM1 null was associated with the increased risk of non-viral HC (OR = 1.337, 95% CI 1.112–1.804, p = 0.005). Subgroup analysis of cirrhosis type revealed that GSTM1 null was a prominent risk factor for alcoholic HC (OR = 1.416, 95% CI 1.112–1.804, p = 0.005). Meanwhile, subgroup analysis of population indicated that the significant differences only existed in Asian population (OR = 1.719, 95% CI 1.212–2.438, p = 0.002). In hospital-based studies, patients with GSTM1 null were more likely in risk of HC (OR = 1.426, 95% CI 1.092–1.863, p = 0.009). Subgroup analysis using genotyping method showed a significant association between GSTM1 null genotype and HC occurrence in the studies employing the multiple PCR genotyping method (OR = 1.559, 95% CI 1.171–2.076, p = 0.002). Based on the results of this analysis, it was concluded that GSTM1 null genotype could increase the susceptibility of non-viral hepatic cirrhosis. In addition, alcohol intake, Asian ethnicity, sample source from hospital and multiple PCR genotyping method may also influence the susceptibility of hepatic cirrhosis.