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 infecte d with hepatitis C virus, yet the clinical course of liver disease is usual ly mild. We investigated whether the hepatitis C virus viral load is influe nced by the haemodialytic procedure and the type of dialyser. Methods. Hepatitis C virus-RNA levels were measured using a quantitative po lymerase chain reaction assay in predialysis blood from 51 hepatitis C viru s-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 membran es with low (cuprofan) or intermediate (cellulose acetate or diacetate) bio compatibility had higher pre-dialysis hepatitis C virus-RNA levels (p<0.05) compared to those dialysed with synthetic high-biocompatibility, high-perm eability polymeric membranes (polyacrylonitrile, polysulfone, polymethylmet hacrylate 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 p re-dialysis viral load. Patients with low pre-dialysis hepatitis C virus-RN A levels (<2.5x10(3) copies/ml) exhibited only minimal changes following th e procedure. Four patients with medium-high basal viral load switched from a low-biocompatibility/low-permeability to a high-biocompatibility/high per meability filter had a marked reduction of viraemia after three weeks, in o ne case followed by a new increase after return to the original filter. Conclusions. Haemodialysis with high-biocompatibility/high-permeability fil ters in hepatitis C virus-infected patients is associated with low blood le vels of hepatitis C virus-RNA. This finding may be of clinical relevance, e specially in patients listed for kidney transplantation.