HEV IgM
Enzyme ImmunoAssay (ELISA) for the determination of IgM antibodies to Hepatitis E Virus in human plasma and sera.
Hepatitis E Virus or HEV is a recently discovered agent of enterically transmitted viral hepatitis. HEV is an unenveloped single-strand RNA virus structurally similar to Calicivirus and is found in the stool of infected patients.
HEV is a serious problem in many developing countries and its first outbreak was reported in 1955 in New Delhi, India. Hepatitis E has never been associated with chronic infection; however a high case-fatality rate has been found among pregnant women.
The cloning and sequencing of HEV genome have lead to the development of serological tests for the detection of anti HEV antibodies.
These tests are based on synthetic immunodominant antigens derived from conservative regions of the virus.
Tests for IgM are used to determine the nature of the infective agent in patients showing symptoms of hepatitis, in order to rule out the possibility of other most severe viral infections (HBV, HDV, HCV).
Microplates are coated with HEV-specific synthetic antigens encoding for conservative and immunodominant determinants derived from ORF2 and ORF3 of all the 4 subtypes.
The solid phase is first treated with the diluted sample and anti HEV IgM are captured, if present, by the antigens. After washing out all the other components of the sample, in the 2nd incubation bound anti-HEV IgM are detected by the addition of polyclonal specific anti hIgM antibodies, labelled with peroxidase (HRP).
The enzyme captured on the solid phase, acting on the substrate/chromogen mixture, generates an optical signal that is proportional to the amount of anti HEV IgM present in the sample. A cut-off value let optical densities be interpreted into anti-HEV IgM negative and positive results.
Neutralization of IgG anti-HEV and Rheumatoid Factor, carried out directly in the well, is performed in the assay in order to block such kind of interferences.
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