Occult HCV infection in liver transplanted patients: frequency and consequences

AIM OF THE STUDY: Occult hepatitis C virus (HCV) infection (OCI) is a potential source of relapse after liver transplantation with subsequent graft damage. The aim of the study was to detect OCI in patients with living donor liver transplantation (LDLT) who achieved sustained virological response (SVR) after sofosbuvir-based antiviral treatment, and to detect risk factors associated with the development of OCI as well as to determine the effect of direct acting antiviral (DAA) therapy after liver transplantation. MATERIAL AND METHODS: 41 patients with living donor liver transplantation who did not receive DAAs before with recurrent HCV infection who achieved a SVR with sofosbuvir-based therapy for 12-24 weeks were recruited. These patients were tested for OCI by HCV-RNA in peripheral blood mononuclear cells (PBMNCs). Those patients with OCI were followed up every 6 months with alanine aminotransferase (ALT), aspartate aminotransferase (AST), and serum HCV-RNA by PCR for 2 years. RESULTS: 92.7% of treated patients achieved HCV SVR 12 weeks. OCI was detected in 4 patients. After follow-up for 18 months, 3 patients continued to have OCI, but one patient presented with progressive elevation of liver enzymes and developed overt HCV infection with positive HCV-RNA PCR in the serum. This patient was retreated with sofosbuvir 400 mg + ledipasvir 90 mg for 12 weeks with resultant negative HCV-RNA PCR in both serum and PBMNCs in addition to normalization of liver enzymes. CONCLUSIONS: Occult HCV infection is a potential source of HCV relapse after liver transplantation which should be investigated for in PBMNCs or liver biopsy.