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.
Soffredini
Roberta
R
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.
Rumi
Maria Grazia
MG
Parravicini
Maria Luisa
ML
Ronchi
Guido
G
Del Ninno
Ersilio
E
Russo
Antonio
A
Colombo
Massimo
M
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