Objective.–This study was undertaken to investigate the presence of autoantibodies against
the main cartilage proteoglycan, aggrecan, in systemic rheumatic disease sera, and to
identify substructure (s) responsible for the autoimmune response. Methods.–Sera were
obtained from 86 patients with various systemic rheumatic diseases, 14 with osteoarthritis
(OA), 18 with cancer and 40 healthy individuals. The presence of autoantibodies against
aggrecan was examined by a solid phase assay and by Western blotting, using …