OBJECTIVETo investigate the potential of hepatitis C virus (HCV) antibody measurement as a clinical approach to determine the infection status and potential for spontaneous-resolution among patients with HCV mono-infection and HCV/human immunodeficiency virus (HIV) co-infection.

METHODSA total of 340 individuals who tested positive for serum anti-HCV antibodies and/or serum anti-HW antibodies were enrolled for study in 2009 from a single village in central China. Markers of liver function (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) and infection (anti-HCV antibodies, CD4⁺ T cell counts, HCV genotype, and HCV viral load) were measured at baseline and follow-up (in July 2012). At follow-up,the subjects were grouped according to ongoing HCV mono-infection (n=129), ongoing HCV/HIV co-infection (n=98), spontaneously resolved (SR)-HCV in mono-infection (n=65), and SR-HCV in HCV/HIV co-infection (n=48) for statistical analysis.

RESULTSAlmost all of the subjects in the ongoing HCV mono-infection group showed high levels of HCV antibodies (S/CO more than or equal to 10), but the majority of the subjects in the SR-HCV in mono-infection group and in the ongoing HCV/HIV co-infection group. The SR-HCV mono-infection group showed a remarkable decrease in HCV antibodies from 2009 (HIV:7.75 ± 3.8; HIV+:7.61 ± 3.47) to 2012 (HIV:5.51 ± 3.67; HIW:4.93 ± 3.35) (HIV:t =10.67, P less than 0.01; HIV+:t =9.52, P less than 0.01). The ongoing HCV/HIV co-infection group showed a positive correlation between HCV antibodies S/CO ratio and CD4⁺ T cell count (r=028, P=0.008). In the ongoing HCV mono-infection group,the levels of HCV antibodies were significantly higher in individuals infected with HCV-1b than in those with HCV-2a (14.74 ± 1.68 vs.14.08 ± 1.44, t=2.20, P=0.03). In the ongoing HCV/HIV co-infection group, the numbers of subjects with elevated (more than 40 U/L) liver function markers were significantly different according to the HCV genotype infection:HCV-1b:ALT, 25/42 vs.16/56 (x²=9.45, P=0.002); HCV2a:AST, 28/42 vs.18/56 (x²=11.49, P=0.001). The HCV RNA positive rate was significantly higher in subjects with high HCV antibody cutoff values (S/CO more than or equal to 10) than in those with low HCV antibody (S/CO less than 10) (HIV:128/151 vs.1/43, x²=102.11, P less than 0.01; HIV+:88/98 vs.10/48, x²=69.44, P less than 0.01), regardless of HIV co-infection. Significantly more subjects in the ongoing HCV mono-infection group had elevated (more than 40 U/L) ALT or AST than the subjects in the SR-HCV mono-infection group with high levels of HCV antibody (S/CO more than or equal to 10) (ALT:57/128 vs.2/23, x²=10.52, P=0.001; AST:57/128 vs.0/23, x²=16.45, P less than 0.01).

CONCLUSIONSerum HCV antibody levels, in combination with other clinical information such as liver function and HIV infection status, may aid in the preliminarily evaluation of an individual's HCV infection status and likelihood for spontaneous resolution. Low levels of HCV antibody (S/CO less than 10) may indicate a better chance of SR-HCV, after ruling out the possibility of suffering from immunosuppressive diseases such as HIV infection.