Background/aims: The detection of serum HCV nucleocapsid (core) antigen, besides being a valid alternative, by virtue of its low cost, to direct analysis of the virus in everyday transfusion practice, also aims to be employed in monitoring patients subjected to antiviral therapy. The verification of strict correlation between the two tests is the presupposition for such use.
Methodology: In a group of 112 HCV-positive subjects, we assessed blood transaminases, viremia (by PCR), and the circulating core antigen (by ELISA).
Results: Only 16 out of 112 patients were AgHCV-negative, with viremia levels in the 10(2) to 10(4) range; 96 patients were HCV-positive, as indicated both by viremia and by Ag detection (1.9 to 292.4pg/mL). Sensitivity of the ELISA test corresponds to 3.6x10(4) IU/mL of viral load. There is an evident aggregation of results in groups according to antigenemia classes and the corresponding viremia levels: <10pg/mL--10(4) IU/mL (6/96); up to 100pg/mL--10(5) IU/mL (55/96); 100-200pg/mL--10(6) IU/mL (31/96); and more than 200pg/mL--10(7) IU/mL (4/96).
Conclusions: AgHCV is correlated with elevation of ALT and high or medium-high viral loads. It can discriminate between ongoing and previous infection and is suitable for monitoring the pharmacological therapy in the presence of sufficiently high viral loads and for evaluating the onset of medium-long-term relapses. Neither the genotypes nor pharmacological therapy appear to affect the comparison of viremia with antigenemia. Moreover, this analysis is cheaper as compared with molecular techniques.