Hepatitis G virus infection in patients transplanted for cryptogenic cirrhosis: Red flag or red herring?

Background. The significance of hepatitis G (HGV) infection in liver transplant recipients is not known. We set out to determine the pre- orthotopic liver transplantation (OLT) prevalence, the pre- and postoperative vital titers of HGV, and the allograft histology in patients infected with HGV who underwent OLT for cryptogenic cirrhosis. Methods. HGV RNA was measured using a research-based branched DNA assay. The assay used a target- specific probe set that was based on the 5'-untranslated region of the HGV genome. Allograft histology was assessed with protocol liver biopsies in all patients who survived longer than 6 months. Results. The preoperative prevalence of HGV infection in recipients transplanted for cryptogenic cirrhosis was 28%. Thirty-seven percent (12 of 33) of recipients who had serum available in the first postoperative month had HGV infection. Mean HGV RNA levels were 9.8 (±4.2) (vital molecular equivalents/mlx10⁶) before OLT and 37.5 (±10.7) at 1 year after OLT. In 4 of the 11 cryptogenic recipients in whom HGV RNA was detectable in the first postoperative month, HGV RNA fell to undetectable levels at the most recent follow-up (mean 70 months). Of the five cryptogenic recipients who continue to have measurable HGV RNA, three have unexplained hepatitis histologically. Conclusions. These fining suggest the following. 1) The prevalence of HGV infection in patients undergoing OLT for cryptogenic cirrhosis is about 25%. 2) In recipients persistently infected with HGV, mean HGV RNA titers increase after OLT. 3) HGV RNA becomes undetectable in about one third of recipients who had detectable HGV RNA in the first month after OLT. 4) Hepatitis of uncertain etiology occurs in 60% (3 of 5) of persistently HGV-infected cryptogenic recipients.