The use of hepatitis C viral RNA levels in liver tissue to distinguish rejection from recurrent hepatitis C

Persistence of hepatitis C virus (HCV) after orthotopic liver transplantati on is almost universal in HCV-infected patients. Histological examination o f liver biopsy specimens can be variable in distinguishing: between recurre nt hepatitis C and acute cellular rejection, The purpose of this study is t o determine whether hepatic HCV RNA levels can be used to distinguish rejec tion from recurrent HCV by determining whether hepatic HCV RNA levels corre late with histological characteristics and clinical course. Seventy-two bio psy specimens were evaluated from 36 liver transplant recipients with H(SV and elevated liver-related enzyme levels. Based on histological findings an d clinical response to therapy, patients were defined as belonging to 1 of 5 groups: (1) definite rejection, (2) probable rejection, (3) indeterminate findings, (4) probable HCV, and (5) definite HCV; Hepatic HCV RNA was quan tified using the Amplicor Monitor assay (Roche Diagnostic Systems Inc, Bran chburg, NJ). There was a difference across groups in HCV RNA levels (P =,04 6), The median H(SV RNA level was 10,695 copies/mg of tissue DNA in the def inite-HCV group compared with 1,024 copies/mg of tissue DNA in the definite -rejection group, Using pairwise comparisons, significant differences were found between definite HCV and definite rejection, probable HCV and definit e rejection, probable HCV and probable rejection, and probable HCV and inde terminate. Our finding support the following conclusions. (1) In liver tran splant recipients, hepatic HCV RNA levels are statistically greater in pati ents with recurrent HCV than rejection, although there is considerable over lap between groups. (2) Patients with low HCV RNA levels were unlikely to h ave recurrent HCV. (3) Patients with minima and indeterminate findings on b iopsy (group 3) had low HCV RNA levels.