Hepatitis C virus-specific markers in pediatric patients with chronic hepatitis C.

Background: The study aimed to investigate hepatitis C virus (HCV) specific markers in chronically infected children. The main objective was to explore the patterns of marker variability.

Methods: HCV RNA, core antigen, anti-HCV IgM, and antibodies to individual viral proteins were detected using commercially available assays or experimental ELISA. RNA genotyping and recombination were performed by sequencing.

Results: HCV RNA and core antigen were detected in serum samples of all children (N.=100). Anti-HCV IgM, anti-NS4AB IgG, and anti-NS5A IgG were revealed less often than antibodies to core and NS3 proteins. To elucidate the cause of this finding, all subjects were divided into 4 groups differing in hepatitis duration. It was anti-NS4AB only whose detection depended on the infection duration. A trend was established that the longer the hepatitis duration, the more frequently anti-HCV IgM was observed. No significant impact of HCV RNA load and NS4A/NS4B amino acid substitutions on anti-NS4AB IgG detection was found. The increase HCV genotype 3 was observed among children infected after 2000. The earliest case of infection caused by HCV intergenotype recombinant RF1_2k/1b was identified in a child vertically infected in 1997.

Conclusions: HCV genotypes and subtypes were found to be variable virus specific markers in children infected in 1997-2015. Over the period, there has been a trend to change the dominant HCV subtype and appearance of recombinant RF1_2k/1b in children. Among humoral markers, anti-NS4AB revealing is depended on chronic hepatitis C duration, while for anti-HCV IgM, only a trend was established. The detection of anti-NS4AB can be helpful in assessing the duration of chronic hepatitis C.