IGM ANTIBODY TO A HEPATITIS-C VIRUS CORE PEPTIDE (CP14) FOR MONITORING ACTIVITY OF LIVER-DISEASE IN PATIENTS WITH ACUTE OR CHRONIC HEPATITIS-C

Antibodies to the hepatitis C virus (HCV) core of various immunoglobul in classes were determined by enzyme immunoassays with three synthetic peptides, CP14 (amino acids 5-40 of the core protein), CP10 (5-23), a nd CP9 (39-74). in 735 patients with chronic type C liver disease, ant i-CP14, anti-CP10, and anti-CPS of IgG class were detected in 99%, 94% , 82%, respectively; those of IgM class in 86%, 69%, and 39%; and thos e of IgA class in 56%, 40%, and 4%. Thus anti-CP14 was more prevalent than anti-CP10 or anti-CPS in every immunoglobulin class. The prevalen ce of IgM anti-CP14 was much higher (P < 0.001) in patients (116/135 o r 86%) than in asymptomatic carriers of HCV (13/39 or 33%). In seven p atients with acute hepatitis C, IgM anti-CP14 continued to decrease in two in whom hepatitis resolved, but increased in five in whom hepatit is once resolved and then exacerbated. IgM anti-CP14 was followed in 3 0 patients with chronic hepatitis C during 24 weeks while they receive d recombinant interferon alpha-2a. IgM anti-CP14 decreased remarkably within 8 weeks in all of them. Thereafter, it continued to decrease in nine patients who responded to interferon and lost HCV RNA from circu lation, but started to increase in five non-responders who continued t o have high titers of HCV RNA, In the remaining 16 patients in whom HC V RNA decreased once and then increased, IgM anti-CP14 continued to de crease till 20 weeks and then increased. These results indicate that I gM anti-CP14 reflects the activity of liver disease, and is useful in following the outcome of patients with acute hepatitis C and in monito ring the response to interferon in patients with chronic hepatitis C. (C) 1994 Wiley-Liss, Inc.