[Serologic diagnosis of acute hepatitis A. Refinement and evaluation of 3 methods of determining specific anti-HAV IgM].
A solid phase radioimmunoassay (RIA) procedure was developed and three methods for detection of IgM specific antibody to hepatitis A virus (anti-HAV IgM) were compared: triple antibody method, 2-MercaptoEthanol (2-ME) for IgM cleavage and Staphylococcal A Protein (StAP) for IgG absorption. Specificity and sensitivity of the tests were checked for evaluating acute and convalescent sera from 40 patients with serologically (seroconversion) diagnosed hepatitis A and 64 sera from patients with various acute viral diseases or with high titre of rheumatoid factor (RF). Specimens to be assayed for anti-HAV IgM were pretreated with 2-ME or StAP and tested by RIa using 125I labelled anti-HAV IgG. Triple antibody method showed to be more sensitive than other two methods giving false positive result in only one serum containing high levels of monoclonal RF. No significant difference in sensitivity and specificity was found between 2-ME and StAP procedure, but these methods were able to detect anti-HAV IgM for only two weeks after the onset of the disease, whereas triple antibody method gave positive results for at last seven weeks.
D000914:Antibodies, Viral / Q000032:analysis*; D006506:Hepatitis A / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D011863:Radioimmunoassay / Q000379:methods
D000914:Antibodies, Viral; D007075:Immunoglobulin M
Diagnosi sierologica dell'epatite acuta da virus a. Messa a punto e valutazione di tre metodiche per la determinazione delle igm specifiche anti-hav.