virological characteristics of hepatitis c virus infection in chronic hemodialysis patients a crosssectional study detection of hepatitis c virus viremia hcv rna in serum of hemodialysis hd patients is crucial for documenting ongoing infection because the clinical and epidemiological importance of antihcv positivity is not clear hcv viremia was studied in 104 hd patients by reverse transcription polymerase chain reaction rt pcr using primers localized in the 5 noncoding region of the viral genome we used two different methods to detect hcv rna a direct pcr amplification of hcv rna from human serum and a standard rt pcr procedure requiring the rna extraction step there were 50 48 antihcv positive patients in this population twentytwo 211 out of 104 patients showed hcv rna in serum by standard rt pcr technique they belonged to the antihcv positive patient group whereas all antihcv negative patients were hcv rna negative prevalence of hcv rna was more than doubled when standard rt pcr was used compared to direct rt pcr protocol there was a good association between serum hcv rna and circulating antihcv antibodies tested by secondgeneration elisa and riba assays hcv viremia was not associated with either the presence or the absence of a particular riba antibody specificity ast and alt levels had no predictive value for hcv viremia because they were repeatedly normal in the majority of viremic patients 1622 73abstract truncated at 250 words