title: Testing of bovine sera by ELISA for IgG, IgM and IgA rheumatoid factors.
abstract: Sera from 19 colostrum-deprived calves less than 1 week old, 24 colostrum-supplemented calves less than 1 week old, 36 3-5-month-old calves and 200 females greater than 9 months of age were tested by ELISA for the presence of IgM, IgG and IgA rheumatoid factors (RF). An increasing level of IgM- and IgG-RF with age was found. IgG-RF levels in the colostrum-supplemented calves were significantly higher than in the non-supplemented calves (p < 0.001). Individual IgG-RF values correlated with serum IgG levels, as determined by zinc sulphate turbidity testing (r=0.59, p < 0.01). No IgA-RF was detected. The cross-reactivity of IgM-RF with heterologous IgG was found to be greatest with rabbit IgG, followed by mouse and chicken IgG. The significance of rheumatoid factors in relation to diagnostic testing is discussed.
authors.affiliation: Veterinary Sciences Division, Department of Agriculture for Northern Ireland, Stormont, Belfast, UK. grahamda@dani.gov.uk
authors.forename: D A
authors.initials: DA
authors.lastname: Graham
authors.forename: K A
authors.initials: KA
authors.lastname: Mawhinney
authors.forename: B M
authors.initials: BM
authors.lastname: Adair
authors.forename: M
authors.initials: M
authors.lastname: Merza
mesh_terms: D000818:Animals; D002417:Cattle / Q000276:immunology*; D002645:Chickens; D003126:Colostrum / Q000276:immunology; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005260:Female; D007112:Immunity, Maternally-Acquired; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008623:Mercaptoethanol; D051379:Mice; D009391:Nephelometry and Turbidimetry; D011817:Rabbits; D012217:Rheumatoid Factor / Q000097:blood*; D013045:Species Specificity; D019287:Zinc Sulfate
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008623:Mercaptoethanol; D019287:Zinc Sulfate; D012217:Rheumatoid Factor