title: Serum IgM and IgA responses in influenza A infections.
abstract: Immunofluorescent serum IgM and/or a significant level of IgA antibody was detected in 87% of 39 cases of current or recent influenza A infection from two to 84 days after the onset of illness. Secondary IgM staining occurred in 5% of sera and a significant correlation was found between complement-fixing and class-specific antibodies. It was estimated that the immunofluorescent test could be diagnostic in 64% of single sera with levels of CF antibody between 32 and 256, and because anti-s antibody was detected in the IgM test this test did not differentiate primary and secondary influenza A infection.
mesh_terms: D000368:Aged; D000914:Antibodies, Viral / Q000032:analysis; D000917:Antibody Formation; D002478:Cells, Cultured; D003168:Complement Fixation Tests; D005455:Fluorescent Antibody Technique; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis*; D066298:In Vitro Techniques; D007251:Influenza, Human / Q000276:immunology*; D007668:Kidney; D007841:Latex Fixation Tests; D008875:Middle Aged
chemical_list: D000914:Antibodies, Viral; D007070:Immunoglobulin A; D007075:Immunoglobulin M