Quantification of serum HCV core antigen by a fluorescent enzyme immunoassay in liver transplant recipients with recurrent hepatitis C - Clinical andvirologic implications

Background Monitoring hepatitis C viremia may be useful in the management o f liver transplant patients with recurrent hepatitis C virus (HCV) infectio n The clinical utility of a newly described fluorescent enzyme immunoassay for the detection of serum HCV core antigen was evaluated, Methods. Serum samples prospectively collected from 57/63 consecutive patie nts transplanted for HCV-related end-stage liver disease were assayed for b oth serum HCV core antigen by fluorescent enzyme immunoassay and HCV RNA le vel using a branched chain DNA signal amplification assay, HCV genotype was determined by restriction fragment length polymorphism analysis based on 5 ' untranslated region. One-and 2-year annual protocol liver biopsies from t hese patients were graded for inflammation, fibrosis, and cholestasis Results. Serum HCV core antigen and HCV RNA were detected in a similar prop ortion of samples (256/281 vs, 260/281, P=NS), and there was an excellent c orrelation between assays (r(2)=0.905, P<0.0001) independent of HCV genotyp e. A conversion equation between HCV core antigen and HCV RNA was construct ed to estimate the HCV core antigen to RNA ratio to be around 231 to 1. Mea n serum HCV core antigen levels peaked initially at 3 months postransplant; but there was significant interpatient variation as to when peak levels oc curred. A high serum HCV core antigen level in the first 6 months was assoc iated with histological deterioration in terms of bridging fibrosis, cirrho sis, severe cholestasis, or retransplantation by 2-year follow-up, Conclusion. Determination of serum HCV core antigen level reflects HCV vire mia and may have clinical implications in liver transplant patients with HC V recurrence.