title: False-positive Rose-Waaler rheumatoid factor titre given by anti-ruminant IgM antibody.
abstract: An antibody against ruminant (goat, sheep, bovine) IgM is described which also cross-reacts with rabbit IgM. The antibody was found in the serum of a patient with adult coeliac disease and a selective IgA deficiency. This patient gave a false high Rose-Waaler rheumatoid factor titre due to the presence of the serum antibody to rabbit IgM that was capable of agglutinating rabbit antibody-sensitised erythrocytes.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000032:analysis; D002417:Cattle; D002446:Celiac Disease / Q000276:immunology; D003429:Cross Reactions; D005189:False Positive Reactions; D005260:Female; D006041:Goats; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D008875:Middle Aged; D011817:Rabbits; D012217:Rheumatoid Factor / Q000032:analysis*; D012756:Sheep
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007075:Immunoglobulin M; D012217:Rheumatoid Factor