Type II collagen-induced arthritis. Studies with purified anticollagen immunoglobulin.

Immunization of rats with native bovine type II collagen results in a polyarthritis by day 21 in approximately 40% of the rats. Sera of these rats contained anticollagen IgG, principally IgG2a. Small amounts of IgG2b were also detected, but IgG1 and IgG2c were absent. By enzyme-linked immunosorbent assay, the paw tissue of these polyarthritic rats was shown to contain anticollagen IgG, the principal subclass being IgG2a, with minor amounts of IgG2b. Immunofluorescence examination of the paws from polyarthritic rats demonstrated deposition of both IgG and C3 on the articular surface. Passive transfer of disease was accomplished by injection of affinity-purified anticollagen immunoglobulin into naive recipients; paw swelling and histopathologic changes were detected 24 hours after transfer, and by immunofluorescence techniques IgG and C3 deposits were demonstrable on the articular cartilage. On passive transfer, neutrophils invaded the joint space and became juxtaposed to the surface of the articular cartilage. Passive transfer of the disease with anticollagen immunoglobulin was unsuccessful after rats were decomplemented with cobra venom factor; immunofluorescence demonstrated IgG but not C3 on the articular cartilage of these decomplemented rats. In rats decomplemented with cobra venom factor, neutrophils did not accumulate in the joint and erosion of articular cartilage was not detected.