Low levels of hepatitis C virus RNA in blood of infected patients under maintenance haemodialysis with high-biocompatibility, high-permeability filters

Background. Patients undergoing maintenance haemodialysis are often infected with hepatitis C virus, yet the clinical course of liver disease is usually mild. We investigated whether the hepatitis C virus viral load is influenced by the haemodialytic procedure and the type of dialyser. Methods. Hepatitis C virus-RNA levels were measured using a quantitative polymerase chain reaction assay in predialysis blood from 51 hepatitis C virus-infected patients dialysed with different membranes. Paired pre- and post-dialysis measurements were also obtained in 18 patients. Results. Patients dialysed using cuprammonium-regenerated cellulose membranes with low (cuprofan) or intermediate (cellulose acetate or diacetate) biocompatibility had higher pre-dialysis hepatitis C virus-RNA levels (p<0.05) compared to those dialysed with synthetic high-biocompatibility, high-permeability polymeric membranes (polyacrylonitrile, polysulfone, polymethylmethacrylate or polycarbonate). Hepatitis C virus-RNA levels were unrelated to the duration of haemodialysis and the presence of abnormal transaminases. A significant reduction (p=0.04) of serum hepatitis C virus-RNA levels was observed after a single haemodialysis, particularly in patients with high pre-dialysis viral load. Patients with low pre-dialysis hepatitis C virus-RNA levels (<2.5x10(3) copies/ml) exhibited only minimal changes following the procedure. Four patients with medium-high basal viral load switched from a low-biocompatibility/low-permeability to a high-biocompatibility/high permeability filter had a marked reduction of viraemia after three weeks, in one case followed by a new increase after return to the original filter. Conclusions. Haemodialysis with high-biocompatibility/high-permeability filters in hepatitis C virus-infected patients is associated with low blood levels of hepatitis C virus-RNA. This finding may be of clinical relevance, especially in patients listed for kidney transplantation.