The clinical diagnostic significance of serum antichondrocyte membrane antibodies in osteoarthritis.

In osteoarthritic patients significantly elevated level of antibodies against human chondrocyte membrane extract was found by double solid phase ELISA which seemed to be more specific for the disease than the antibody level of collagen types II, IX and XI. Altogether 86 patients with a mean age of 53.6 years and a ratio of 25% men and 75% women suffering from severe hip joint osteoarthritis were studied in comparison with 44 control persons with a mean age of 35.8 years and identical sex distribution. The specificity of reacting antibodies was proved partly by inhibition test and partly by the fact that the ELISA reaction could be produced only by proteins of the membrane extract bound to collagen (II) after affinity chromatography. The diagnostic importance of the methods is striking, in view of the lack of any other objective laboratory tests for the disease.