Biological dynamics of viral load in hemodialysis patients with hepatitis C virus

The biological dynamics of hepatitis C virus (HCV) viremia in uremic patien ts with chronic infection have not been fully characterized. We prospective ly studied fluctuations of HCV-RNA in sera from 52 patients with end-stage renal disease who were undergoing maintenance hemodialysis (HD) and had chr onic HCV infection. We measured HCV viremia monthly over the course of 13 m onths with the branched-chain DNA(bDNA) signal amplification assay and pros pectively analyzed liver function, expressed by monthly serum aspartate (AS T) and alanine aminotransferase (ALT) determinations. We observed three dif ferent patterns of HCV viremia: (1) patients persistently positive by bDNA assay (persistent viremia; 23 of 52 patients; 44%), (2) individuals with al ternatively positive and negative results (intermittent viremia; 17 of 52 p atients; 33%), and (3) patients persistently negative by bDNA assay (12 of 52 patients; 23%), The HCV viral load over the follow-up was greater among patients with persistent compared with intermittent viremia (persistent, 31 .7 x 10(5) Eq/mL; range, 6.3 x 10(5) to 16.03 x 10(6) Eq/mL versus intermit tent, 10.4 x 10(5) Eq/mL; range, 1.1 x 10(5) to 9.4 x 10(6) Eq/mL; P = 0.00 01), In addition, patients with persistent viremia had over time greater AS T and/or ALT activities than the intermittent group (AST: persistent, 26.5 IU/L; range, 9.6 to 73.7 IU/L versus intermittent, 21.3 IU/L; range, 8 to 5 6.8 IU/L; P = 0.001 and ALT: persistent, 14.7 IU/L; range, 3.7 to 57.9 IU/L versus intermittent, 10.9 IU/L; range, 2.3 to 52.1 IU/L; P = 0.001). In th e group with persistent viremia, the mean difference between maximum and mi nimum values of HCV-RNA observed in each individual patient was 2.09 +/- 0. 7 natural logarithm (Log(n)) and in intermittent viremic patients, 1.55 +/- 1 Log(n) (P = 0.045), The HCV load at study entry (19.4 x 10(5) Eq/mL) was rather low and did not change versus the end of follow-up in all patients (P = not significant [NS]), In the entire group, the fluctuations in HCV-RN A levels over time between and within individuals were not significant (P = NS), No difference in variability of HCV-RNA values over time between pati ents infected with different HCV genotypes was seen. In conclusion, three d ifferent patterns of HCV viremia in HD over time were assessed; one third o f viremic patients had intermittent viremia, and those patients had less HC V-RNA, enzyme-linked immunosorbent assay, and aminotransferase activity tha n did patients with persistent HCV load. Larger fluctuations in HCV RNA lev els occurred in patients with persistent than with intermittent HCV viremia . However, the viremic HCV load was low and relatively stable over a 13-mon th follow-up in our population. Studies with longer observation periods are warranted to understand fully the natural history of HCV in these immunosu ppressed individuals. (C) 2000 by the National Kidney Foundation, Inc.