BACKGROUND The significance of immunoglobulin (Ig) M antibody to hepatitis C virus (HCV) core antigen was studied in 60 patients with HCV infection after orthotopic liver transplantation (OLT) diagnosed by polymerase chain reaction.

RESULTS One year after liver transplantation, 29/60 (48%) patients had chronic hepatitis on graft biopsy. The presence of anti-HCV core IgM one month (p=0.004) and 12 months (p=0.003) after OLT was positively correlated with recurrence of chronic hepatitis. The positive predictive value of anti-HCV core IgM detected one month after transplantation was 0.88. A significant relationship was observed between severity of graft disease and presence of anti-HCV core IgM 12 months after transplantation. The mean Knodell score was 8.9 in anti-HCV core IgM positive patients compared with 3.6 in those who were anti-HCV core IgM negative (p=0.001). The presence of IgM anti-HCV did not correlate with serum HCV RNA level or HCV genotype.

CONCLUSION We confirm that the presence of anti-HCV core IgM after OLT is a marker of HCV induced graft damage. The recurrence and severity of HCV hepatitis in patients undergoing OLT for HCV cirrhosis is related to the presence of anti-HCV core IgM after liver transplantation. These findings have diagnostic relevance and confirm that measurement of IgM anti-HCV core may help to better monitor the treatment of HCV recurrence after transplantation.