Serum levels of hepatitis C virus core antigen as a marker of infection and response to therapy.
OBJECTIVE
Hepatitis C virus (HCV) core antigen is a recently developed marker of hepatitis C infection. We compared the predictive power of HCV core antigen with reverse transcription polymerase chain reaction (RT-PCR) and branched DNA assay for HCV-RNA as markers of infection and response to interferon therapy.


METHODS
Four hundred and forty-four sera from 111 patients (65 men, 52 yr) with chronic hepatitis C, receiving ribavirin together with standard interferon (n = 61) or pegylated interferon (n = 50) were retrospectively investigated.


RESULTS
Pretreatment, RT-PCR, branched DNA (median 621,887 IU/ml), and HCV core antigen (median 57 pg/ml) gave positive results in 100%, 99%, and 94% of the sera; the correlation between HCV core antigen and branched DNA was 0.75. The median HCV RNA level among the 7 of 111 (6%) patients that had a negative core Ag result was 15,016 IU/ml. Pretreatment levels of HCV core antigen were significantly lower in the 41 patients with a sustained virological response than in the 39 relapsers and 31 nonresponders (17 pg/ml, 114 pg/ml, 58 pg/ml; p-value 0.005). Independently of treatment schedule, wk 12 more than 2 log(10) reduction of viremia or a negative result for HCV core antigen had 100% negative predictive value (NPV) for a response to therapy compared to 94% for negative RT-PCR. The positive predictive value (PPV) of HCV core antigen and branched DNA was only 47% and 48%.


CONCLUSIONS
In conclusion, the HCV core antigen is a less sensitive test of HCV viremia than HCV-RNA assays and is competitive with the bDNA assay as an early predictor of a nonresponse.
A.M. Migliavacca Center for Liver Disease, Department of Gastroenterology and Endocrinology, IRCCS Maggiore Hospital and University of Milan, Via Pace 9, 20122 Milan, Italy.
Roberta
R
Soffredini
Maria Grazia
MG
Rumi
Maria Luisa
ML
Parravicini
Guido
G
Ronchi
Ersilio
E
Del Ninno
Antonio
A
Russo
Massimo
M
Colombo
D000328:Adult; D015415:Biomarkers / Q000097:blood*; D015331:Cohort Studies; D016001:Confidence Intervals; D004359:Drug Therapy, Combination; D005260:Female; D018936:Hepatitis C Antigens / Q000032:analysis*; D019698:Hepatitis C, Chronic / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology*; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D011994:Recombinant Proteins; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012254:Ribavirin / Q000008:administration & dosage; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014758:Viral Core Proteins / Q000032:analysis / Q000276:immunology*
D015415:Biomarkers; D018936:Hepatitis C Antigens; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D014758:Viral Core Proteins; D012254:Ribavirin