Detection of Occult Hepatitis C Virus Infection (OCI) in Bone Marrow Mononuclear Cells

Abstract

Background and aim: Occult HCV infection (OCI) diagnosis by cellular-PCR encourages further research for more understanding of extrahepatic tissues affection during non-viremias. OCI among Egyptians recruits more attention because of the convenient diagnostic tools and the availability of direct acting antivirals (DAAs). Our study aims to recognize HCV-infection of bone marrow mononuclear cells (BMMCs) in antiviral IgG-antibody seropositive nonviremic subjects. Subjects and Methodology: Our case control study included 70 subjects who were divided into three groups: - I: non-viremic IgG-seronegative controls (n=25), II: naive HCV-RNA viremic IgG-seropositive controls (n=15), III: naive non-viremic IgG-seropositive patients (n=30). Sera of all study subjects were screened for anti-HCV IgGantibodies by ELISA and for HCV-RNA by PCR. BMMCs and peripheral blood mononuclear cells (PBMCs) of all study populations were tested for HCV-RNA infections by cellular-PCR. Results and conclusions: HCV-RNA viremias were seen when bone-marrow is functioning (P<0.05), while nonviremias were common in bone-marrow failure (P<0.05). There was 100% concordant positivity between serum and cellular HCV-RNA-PCRs in viremic patients. HCV-BMMCs and PBMCs PCRs respectively added extra 20% (P=0.024) and 13.33% (P=0.119) as newly diagnosed infections compared to none by serum-PCR in IgG-antibody seropositive non-viremic subjects. Respectively, non-viremic population (n=55) showed 14.29% and 9.1% positive intra-mononuclear cells HCV-RNA infection in bone marrow (P=0.002) and peripheral blood (P=0.057) compared to serum PCR. In conclusion, consecutive screening of peripheral blood and bone marrow mononuclear cells for HCV-RNA detection by cellular-PCR recognizes naive OCI in IgG-seropositive non-viremic patients. Functioning bone marrow would be required for persistence of HCV-RNA viremia.