title: IgM-rheumatoid factors cross-reactive with IgG and a cell nuclear antigen: apparent 'masking' in original serum.
abstract: Fourteen out of fifteen IgM-rheumatoid factor (IgM-RF) preparations isolated from high-titred seropositive rheumatoid sera by affinity chromatography on immobilized human IgG have been shown to cross-react with a cell nuclear antigen, as manifest by positive immunofluorescent anti-nuclear antibody (ANA) staining on rat liver and kidney tissue sections. The cross-reacting ANA activity within isolated IgM-RF preparations was inhibitable by both human and rabbit IgG, as well as by isolated rat liver chromatin, and could be isolated from seropositive ANA-negative sera. It would appear that this cross-reacting ANA activity can be masked in the original seropositive serum and may often require purification of RF from serum for its manifestation.
mesh_terms: D000818:Animals; D000941:Antigens; D002467:Cell Nucleus / Q000276:immunology*; D003429:Cross Reactions; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D011817:Rabbits; D051381:Rats; D012217:Rheumatoid Factor
chemical_list: D000941:Antigens; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012217:Rheumatoid Factor