REF:

E2201 (Microwell Plate)

INTENDED USE:

This kit is an enzyme-linked immunosorbent assay for qualitative detection of IgM-class antibodies to hepatitis C virus in human serum or plasma. It is intended for clinical diagnosis, management and follow-up of patients related to infection with hepatitis C virus.

SUMMARY:

Hepatitis C virus (HCV) is an envelope, single stranded positive sense RNA (9.5 kb) virus belonging to the family of Flaviviridae. Six major genotypes and series of subtypes of HCV have been identified. Isolated in 1989, HCV is now recognized as the major cause for transfusion associated non-A, non-B hepatitis. The disease is characterized with acute and chronic form although more than 50% of the infected individuals develop severe, life threatening chronic hepatitis with liver cirrhosis and hepatocelular carcinomas. Since the introduction in 1990 of anti-HCV screening of blood donations, the incidence of this infection in transfusion recipients has been significantly reduced. The first generation of HCV ELISAs showed limited sensitivity and specificity and was produced using recombinant proteins complementary to the NS4 (c100-3) region of the HCV genome as antigens. Second generation tests, which included recombinant / synthetic antigens from the Core c22) and nonstructural regions NS3 (c33c, c100-3) and NS4 (c100-3, c200) resulted in a remarked improvement in sensitivity and specificity. Clinical studies show that significant amount of HCV infected individuals develop antibodies to NS5 non-structural protein of the virus. For this, the third generation tests include antigens from the NS5 region of the viral genome in addition to NS3 (c200) and NS4 (c200) and the Core (c22). Third generation tests have improved sensitivity and shorten the time between infection with HCV and the appearance of detectable antibodies (window period) to 60 days.

IgM response to both the structural and non-structural antigens of HCV has been demonstrated and some studies indicated that detectable IgM response occurs on a majority of cases to the structural (core) antigen. IgM antibody against HCV core protein can be detected in accurately diagnosing HCV infectivity and viremia in blood. IgM anti-HCV core level is associated mainly with HCV genotype and secondly with liverdisease necroinflammatory activity. The emergence of HCV IgM may be of four types: (1) persistent positive type; (2) intermittent positive type; (3) transient positive type; (4) persistent negative type. Usually IgM responses type 1 and 2 indicates progressive liver damage. If the patients were of transient positive type, they would usually recover. Although there is a significant correlation between the levels of serum HCV IgM and ALT, no significant correlation occurre between the levels of serum ALT HCV IgG. Secretion of HCV IgM core antibodies after OLT seems associated with recurrence of HCV-associated liver disease and has diagnostic significance. It is useful and important for patients with chronic hepatitis C, to detect HCV IgM for estimating the extent of progressive liver damage and guiding the antiviral therapy.