The diagnostic significance of autoantibodies against cartilage components or their counterparts in destructive articular diseases.

In this work four different types of antibodies to collagens, membrane protein of chondrocytes (MP), cartilage matrix proteins (CMP) and heat shock proteins (HSP-s) were tested in order to find an available clinical laboratory method for diagnostic and monitoring purposes in patients suffering from osteoarthritis. From the point of view of diagnostic efficiency, the estimation of antibody level to MP seemed to be the best and as a supplementary method the determination of rheuma factor was recommended. The anticollagen antibody estimation is less sensitive, anti CMP antibodies are not detectable. In spite of immunological crossreaction between HSP and cartilage matrix component the antibody level against HSP has no correlation with osteoarthritis. The appearance of humoral reaction, antibodies against different cartilage specific collagens and chondrocyte membrane proteins, is an epiphenomenon, however as the supposed immune complexes, trapped in a cartilage, play an important role in the damage of cartilage which may explain the self-perpetuating and chronic nature of cartilage degradation on osteoarthritis.