A Variant in PNPLA3 Associated With Fibrosis Progression but not Hepatocellular Carcinoma in Patients With Hepatitis C Virus Infection

Background & aims: A single nucleotide polymorphism (SNP) in the patatin-like phospholipase domain containing 3 gene (PNPLA3, rs738409) has been associated with fibrosis and development of hepatocellular carcinoma (HCC) in patients with nonalcoholic steatohepatitis, although its association with outcomes in patients with hepatitis C virus (HCV) infection is less clear. We evaluated the association between this SNP in PNPLA3 and fibrosis progression and development of HCC among HCV-infected patients.

Methods: We performed a secondary analysis of data from participants in the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial. Patients were randomly assigned to groups given weekly pegylated interferon or no further therapy for 3.5 y and then followed without further treatment until October 2009. Multivariate logistic regression was used to identify factors associated with fibrosis at baseline, fibrosis progression (defined as 2-point increase in Ishak score), and HCC development.

Results: Among 937 HCV patients with known PNPLA3 genotype, 384 (41.0%) had cirrhosis at baseline. The PNPLA3 CG/GG SNP at rs738409 was significantly associated with the presence of cirrhosis (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.34-2.30), after adjusting for age, sex, diabetes, and race. Among 493 patients without cirrhosis at baseline who had at least 1 follow-up biopsy, 142 had fibrosis progression. In multivariate analyses, fibrosis progression was associated with obesity (OR, 1.67; 95% CI, 1.11-2.51) and the PNPLA3 CG/GG genotype (OR, 1.70; 95% CI, 1.13-2.56). PNPLA3 genotype was not associated with HCC development (P = .85). Using these data to update prior meta-analysis results, the rs738409 SNP in PNPLA3 was not significantly associated with development of HCC in HCV-infected patients (OR 1.29; 95% CI, 0.97-1.99).

Conclusions: Based on data from the HALT-C trial, the PNPLA3 CG/GG SNP at rs738409 is associated with fibrosis progression but not development of HCC in patients with HCV infection.