GBV-C Protects against Liver Disease Progression in HIV-HCV Coinfected Individuals

GBV-C -- also sometimes called hepatitis G virus -- is related to hepatitis C virus (HCV), but causes no known liver disease. Several prior studies have shown that coinfection with GBV-C is associated with significantly slower HIV disease progression.

According to the results of a study reported in the December 2007 issue of Gastroenterology, GBV-C may also protect against liver disease progression in HIV positive individuals with hepatitis C virus (HCV) coinfection; findings were previously reported at 57th American Association for the Study of Liver Diseases (AALSD) in October 2006.

The study included 158 HIV-HCV coinfected patients, recruited between January 1996 and October 2005, who had never received interferon-based therapy for hepatitis C. Two serum specimens collected at least 18 months apart were tested for GBV-C RNA by reverse transcription-polymerase chain reaction (PCR) with NS5B gene primers and confirmed using E2 gene primers and sequencing. Antibodies to GBV-C E2 protein were also measured. Liver-related morbidity and mortality were assessed using patient medical records.

Results

• 57 study participants (36%) had detectable GBV-C RNA.

• 94 participants (59%) had evidence of prior exposure to GBV-C based on combined PCR and antibody results.

• Demographic characteristics were similar in the GBV-C positive and negative groups (nearly 90% white men, mean age about 35 years); 60% had HCV genotype 1.

• Both groups had similar HIV viral load and duration of HIV infection, but the patients with detectable GBV-C had a slightly higher CD4 cell count.

• 34 patients (21%) patients had evidence of cirrhosis, with 20 having compensated and 14 having decompensated cirrhosis.

• In a multivariate analysis, active GBV-C RNA was significantly associated with a reduction in the rate of both compensated and decompensated cirrhosis (hazard ratio 0.27; P = .03).

• GBV-C RNA was also associated with longer cirrhosis-free survival for patients with a given duration of HCV infection (P = .006).

• However, no significant effect on the rate of liver-related death or overall survival was observed.

Conclusion

Based on these findings, the study authors concluded, "In these HCV-HIV coinfected patients, GBV-C RNA was associated with a significant reduction in the severity of HCV-related liver disease."

Since GBV-C coinfection appears to have a beneficial effect on both HIV disease and HCV-related liver disease progression, some researchers have suggested that GBV-C might one day be used as a form of therapy.

01/25/08

Reference
MD Berzsenyi, DS Bowden, HA Kelly, and others. Reduction in hepatitis C-related liver disease associated with GB virus C in human immunodeficiency virus coinfection. Gastroenterology 133(6): 1821-1830. December 2007.