- Synovial fluid levels of tumor necrosis factor alpha and oncostatin M correlate with levels of markers of the degradation of crosslinked collagen and cartilage aggrecan in rheumatoid arthritis but not in osteoarthritis. Manicourt, D.H., Poilvache, P., Van Egeren, A., Devogelaer, J.P., Lenz, M.E., Thonar, E.J. Arthritis Rheum. (2000)