Collagen antibodies and collagen- anticollagen immune complexes in rheumatoid arthritis

Serum, synovial fluid and synovial fluid cells of 14 patients with classic rheumatoid arthritis and of 5 controls were investigated serologically in regard to rheumatoid factors and collagen antibodies and by immunofluorescence double staining in regard to localization of collagen and gammaglobulin in fluid cells. Three patterns of staining were observed: a) gammaglobulin inclusions, b) gammaglobulin and collagen in identical localization, c) collagen inclusions. While distinct staining for gammaglobulin appeared only in seropositive cases, collagen inclusions were only observed in RA, however in seropositive and seronegative cases. In 5 RA cases collagen and gammaglobulin were demonstrated additionally in such identical localization that conclusion in regard to collagen-anticollagen immune complexes seems justified. 9 of 14 RA cases had collagen antibodies, all cases were collagen antibody positive which had collagen and gammaglobulin in identical localization in same inclusions.