title: Persistence of a positive test for IgM antibodies to hepatitis A virus in late convalescent sera.
abstract: We had the opportunity to carry out a long-term follow up of 15 patients with viral hepatitis Type A. The serum IgM response to hepatitis A virus (HAV) was investigated with a commercially available kit (HAVAB-M). IgM antibodies were detected in all specimens collected during the acute phase of the disease and during early convalescence (first 3 months). However, there was a clear decrease in the "sample-to-cutoff" ratio (s/co ratio) after the first 2 months. Serum samples were available from six patients 30 to 32 months after onset of illness. Two of these were positive for IgM anti-HAV, but the s/co ratios were low. These results point to the need for careful evaluation of the diagnosis of acute or recent viral hepatitis Type A when low s/co ratios are obtained.
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis*; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006506:Hepatitis A / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D008297:Male; D011863:Radioimmunoassay
chemical_list: D000914:Antibodies, Viral; D007075:Immunoglobulin M