[Distribution of immunoglobulin classes in joint capsules in osteoarthritis (arthrosis) and chronic polyarthritis]

The distribution of the various classes of immunoglobulins (IG) in synovial membranes in rheumatoid arthritis (RA) and in osteoarthritis (OA) is analyzed. Both plasma cells and extravascular deposits of immunoglobulins are stained using class-specific antisera and the peroxidase-antiperoxidase technique. It can be shown that the local humoral immune response in RA-Synovialitis occurs at a higher level than that of OA; inflammatory infiltrates are denser and plasma cells are activated to a higher degree which is evident in the greater intensity of cytoplasmic staining. While there is no difference in the relation between singular classes of IG in these two groups of diseases, the fraction of plasma cells synthesizing an immunoglobulin is greatly elevated in RA-Synovialitis and there is a correlation of this to the morphological degree of RA-Synovialitis. This applies even more to extravascular deposits of IG with rheumatoid-factor-activity. The determination and staining of extravascular immunoglobulins with a polyvalent anti-human-serum or with antisera specific for the gamma, alpha, and mu-antigens of heavy chains as well as the demonstration of rheumatoid-factor activity of these IG constitute a possibility to histochemically discriminate between RA-Synovialitis and OA-induced synovialitis. In OA, intensely stained areas of IG with rheumatoid-factor-activity located extravascularly are never found.