Antibody- and genome-based identification of recent HCV infection.

The diagnosis of recent HCV infection remains challenging due to the absence of serological markers specific to the early phase of infection. Clinical follow-up and seroconversion to anti-HCV immunoglobulin (Ig)G, detection of viral RNA and changes in levels of blood biomarkers associated with liver pathology provide circumstantial evidence of recent HCV infection. Studies based on anti-HCV IgG avidity, antigen-specific antibody profiling, HCV viral load fluctuations and signature changes in the HCV genome show potential to discriminate recent from persistent HCV infection.

Laboratory diagnostics for hepatitis C virus infection.

Identification of prevalent infection by hepatitis C virus (HCV) is based serologically on detecting anti-HCV immunoglobulin G, using immunoassays, immunoblot assays, and, more recently, immunochromatography-based rapid tests. None discriminate between active and resolved HCV infection. Tests for detecting HCV RNA identify active HCV infection but are costly.

Distinguishing acute from chronic hepatitis C virus (HCV) infection based on antibody reactivities to specific HCV structural and nonstructural proteins.

Currently available serological assays for detection of antibodies to hepatitis C virus (HCV) cannot reliably discriminate acute from chronic HCV infection. We developed a multiplexed, flow-cytometric microsphere immunoassay to measure anti-HCV-IgG reactivities to the core, NS3, NS4, and NS5 HCV recombinant proteins and applied it to 99 serum samples from 24 anti-HCV seroconverters and 141 anti-HCV-IgG and HCV RNA-positive plasma specimens from chronically infected people. Differences in the geometric means or means of signal/cutoff ratios between the two sample sets were statistically significant for all the antigens tested.