PATTERNS OF HEPATITIS-C VIREMIA IN PATIENTS RECEIVING HEMODIALYSIS

Objectives: Chronic hepatitis C virus (HCV) infection is common in pat ients who receive hemodialysis (HD). The aim of this study was to dete rmine the natural history of hepatitis C viremia and the clinical util ity of quantitation and genotyping of HCV in this population of patien ts. Methods: Consecutive sera from two groups of HD patients who were HCV RNA positive, a group of 33 patients treated with interferon alfa (5 MU, three times a week for 4 months) and a group of 31 untreated pa tients, were analyzed by qualitative polymerase chain reaction, quanti tative polymerase chain reaction, and a line probe assay for genotypin g. Results: Serum HCV RNA was detected continuously in 20 of 31 untrea ted patients (65%), and 11 patients (35%) showed a fluctuating pattern of viremia with virus-free intervals of up to 4 wk. Twenty-five of 33 patients (76%) treated with interferon alfa became HCV RNA negative d uring therapy; eight of these 25 patients had a breakthrough, which wa s transient in seven patients and persistent in one. Of the remaining 24 end-of-treatment responders, 17 relapsed after completion of therap y, and seven (21%) had a sustained response with undetectable serum HC V RNA for 1 yr of follow-up. Initial serum HCV RNA levels in HD patien ts were generally low (median, 1 x 10(5) genome eq/ml). Sustained resp onders had significantly lower median levels of viremia (4 x 10(4) eq/ ml) than relapsers and nonresponders (9 x 10(4) and 1.8 x 10(5) eq/ml, respectively). Genotyping revealed a predominance of genotype 1a (33% ) and 1b (48%). Conclusions: This study documents that fluctuating hep atitis C viremia with periods of undetectable HCV RNA is common and th at low viral load predicts a sustained response to interferon therapy in HD patients. Diagnosis of chronic hepatitis C and monitoring of int erferon therapy in HD patients should include initial HCV RNA quantita tion and repeated qualitative measurements of HCV RNA.