High serum gamma-glutamyltransferase level after hepatitis C virus elimination is a risk factor for the development of hepatocellular carcinoma.

Aim: Gamma-glutamyltransferase (GGT) is known as an oxidative stress marker, induced by alcohol consumption and metabolic disorders, and is reported as a predictor of hepatocellular carcinoma (HCC) development after hepatitis C virus (HCV) elimination. However, it is not clear whether GGT serves simply as a surrogate marker for overlapping metabolic diseases or reflects HCV-specific carcinogenicity. We investigated the association between GGT and hepatocarcinogenesis after achieving a sustained viral response (SVR), accounting for drinking habits or diabetes, and examined predisposing factors associated with GGT levels after SVR.

Methods: This is a prospective, multicenter, and observational study using the database of 1001 patients after HCV eradication with direct-acting antiviral agents. The association of GGT at SVR with cumulative HCC development was examined in a multivariate analysis using Cox proportional hazard models after adjustment for covariates including alcohol and diabetes. The association between oxidative stress markers or genetic factors and GGT levels was analyzed.

Results: High GGT levels at SVR were associated with HCC development (HR] 2.38, 95% CI 1.10-5.17). This association was also significant when restricted to patients without alcohol consumption or diabetes (HR 8.38, 95% CI 2.87-24.47). GGT levels were correlated with serum growth differentiation factor 15 levels, a marker of mitochondrial dysfunction. Single-nucleotide polymorphisms of ZNF827 and GDF15 were associated with high GGT levels.

Conclusions: High GGT levels at SVR were associated with HCC development after accounting for alcohol consumption and diabetes. GGT levels are influenced by genetic predisposition and may reflect mitochondrial dysfunction after HCV eradication.