[Serum and articular immune complexes detection by the antibody-dependent cytotoxicity inhibition reaction in inflammatory rheumatological conditions and connective tissue disorders (author's transl)].

Detection of circulating and intra-articular soluble immune complexes, has been done in 28 rheumatoid arthritis, 8 mixed connective tissue diseases and 8 other connective tissue diseases. The method used, is based on a competition reaction in the antibody dependent lymphocytotoxicity reaction (ADC). In rheumatoid arthritis serum immune complexes were detected in 75% of the seropositive cases and 66% of the seronegative ones. The mean level of complexes is higher in the former form of the disease. In a given patient, the concentration of immune complexes in joint fluid, is higher than in serum. Immune complexes were present in the serum of 75% of patients with mixed connective tissue disease, but, here, at a concentration lower than in rheumatoid arthritis and systemic lupus erythematosus. It is proposed that measurement of serum immune complexes, can also be an interesting parameter in the follow-up of the patients.