HIGH TITERS OF ANTIBODIES INHIBITING THE BINDING OF ENVELOPE TO HUMAN-CELLS CORRELATE WITH NATURAL RESOLUTION OF CHRONIC HEPATITIS-C

Most cases of hepatitis C virus (HCV) infection result in chronic dise ase; however, a very small fraction of patients naturally clear the vi rus and resolve chronic hepatitis. In an attempt to correlate immune r esponse with chronic disease resolution, we compared the antibody resp onse in patients with different outcomes of the infection. Antibody re sponses to HCV structural proteins were assessed in 34 patients origin ally diagnosed with acute hepatitis. Five cases resolved acute infecti on, 22 developed chronic hepatitis, and 7 naturally resolved chronic h epatitis C, To estimate HCV neutralizing antibodies we used the neutra lization of binding (NOB) assay, which evaluates inhibition of the env elope-2 protein binding to human cells, Enzyme-linked immunosorbent as say was used for the quantitative assessment of serum antibodies, The presence of HCV RNA was ascertained by reverse transcription-polymeras e chain reaction. In 6 of 7 patients naturally recovered from chronic hepatitis C, the emergence and the persistence (for more than 3 months ) of high serum titers (>1/600) of NOB antibodies coincided with virus clearance and clinical resolution of hepatitis, NOB antibody activity was observed in only 2 of 5 patients recovered from acute hepatitis C , Chronic patients who did not show any resolution during the course o f the study developed low or no NOB antibodies. Because of the correla tion between prolonged high NOB titers and natural resolution of chron ic hepatitis C, vaccination or passive immunization aimed at high tite rs of NOB antibodies may be valuable new therapeutic approaches for ch ronic hepatitis C.