BACKGROUND: Hepatitis C virus (HCV) RNA can be detected in sera and peripheral blood mononuclear cells (PBMC) of patients undergoing chronic hemodialysis. However, the natural course of HCV infection in this group of patients is not fully known. Although the exact mechanism of HCV replication is not completely explained, there is evidence that HCV replicate through synthesis of complementary negative (-) RNA strand, whereas positive (+) RNA strand serves as a template. Thus, the detection of negative HCV-RNA strand can be regarded as a marker of ongoing viral replication.
MATERIAL AND METHODS: We investigated the prevalence of (+) and (-) strands of HCV-RNAs in sera and PBMC of 45 chronically hemodialyzed patients using PCR methods. We also determined HCV genotypes and their subtypes by Inno-LIPA method. RESULTS: Eight (17.8%) of analyzed patients were anti-HCV positive. In this group, we detected HCV-RNA (+) strands in sera and PBMC in 2 and 4 cases respectively, whereas HCV-RNA (-) ones were found in PBMC of 4 patients. Among the remaining 37 anti-HCV negative patients we found HCV-RNA positive strands in sera and PBMC in 2 and 3 cases respectively, whereas HCV-RNA negative strand was present in PBMC in one of them. 
CONCLUSIONS: Our results indicate that HCV actively replicate in PBMC in chronically hemodialyzed patients. In number of patients HCV-RNAs can be detected only in PBMC without concomitant presence of viremia or anti-HCV in sera. We did not find any correlation between genotypes of HCV and presence of HCV-RNAs strands in PBMC of the patients.

Keywords: HCV infection, Dialysis, positive and negative HCV-RNA strands