Rheumatoid arthritis and collagen antibodies.

By using the complement fixation test, antibodies against collagen were examined. Pronase-solubilized insouble collagen served as antigen (20 degrees, 24 hours, collagen: enzyme ratio 10:1). Of 79 patients suffering from rheumatoid arthritis, the presence of collagen antibodies was demonstrated in 8 cases. 56 patients with degenerative joint disease served as the control group, in which collagen antibodies were detected in only one single patient.