ANTIBODY-RESPONSE TO CORE, ENVELOPE AND NONSTRUCTURAL HEPATITIS-C VIRUS-ANTIGENS - COMPARISON OF IMMUNOCOMPETENT AND IMMUNOSUPPRESSED PATIENTS

Some immunosuppressed patients with hepatitis C virus infection do not have detectable levels of antibody to hepatitis C virus on second-gen eration enzyme immunoassay. Antibodies to the envelope and nonstructur al region 5 proteins have not been examined. Four groups of patients w ith hepatitis C virus infection were studied: (a) 20 immunocompetent p atients, (b) 15 hemodialysis patients, (c) 17 kidney transplant recipi ents and (d) 3 acute leukemia patients who underwent bone marrow trans plantation. Serum samples were tested for antibody to hepatitis C viru s with a second-generation enzyme immunoassay and multiantigen enzyme immunoassays and for hepatitis C virus RNA with a nested polymerase ch ain reaction assay. All the immunocompetent patients reacted to C25, C 22 and C33C; 90% reacted to nonstructural region 5 antigen and 80% rea cted to C100-3. Only 55% reacted against yeast-derived e1 and e2 antig ens, but all reacted against vaccinia virus-expressed N e1 and e2 anti gens, indicating that the envelope epitopes are conformational and gly cosylated. Sixty-five percent to 90% of dialysis and kidney transplant patients reacted to C25, C22 and N e1 and e2, but only 12% to 60% rea cted to C100-3, C33C and nonstructural region 5 antigen. Diminution or loss of reactivity to hepatitis C virus antigens was observed after k idney and bone marrow transplantation, with C25 and N e1 and e2 less a ffected. Our data suggest that incorporation of C25 and N e1 and e2 an tigens in the assay for antibody to hepatitis C virus would improve th e detection of hepatitis C virus infection in immunosuppressed patient s.