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.

Objective: To compare synovial fluid (SF) levels of oncostatin M (OSM), tumor necrosis factor alpha (TNFalpha), and interleukin-6 (IL-6) in patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and to determine which correlate best with SF levels of antigenic keratan sulfate (Ag KS), a marker of aggrecan catabolism, and pyridinium crosslinks, markers of the degradation of mature collagen molecules.

Methods: SF was drawn from the knee joints of patients with RA (n = 31) or OA (n = 31). Levels of Ag KS, D-pyridinoline (D-Pyr), pyridinoline (Pyr), OSM, TNFalpha, and IL-6 were measured by enzyme-linked immunosorbent assay.

Serum levels of hyaluronan, antigenic keratan sulfate, matrix metalloproteinase 3, and tissue inhibitor of metalloproteinases 1 change predictably in rheumatoid arthritis patients who have begun activity after a night of bed rest.

Objective: To evaluate whether and how moderate physical activity following a night of rest influences serum levels of matrix metalloproteinase 3 (MMP-3), tissue inhibitor of metalloproteinases 1 (TIMP-1), antigenic keratan sulfate (Ag KS), and hyaluronan (HA) in 10 normal subjects and 38 patients with rheumatoid arthritis (RA).

Methods: Blood was obtained from 20 RA patients before they arose from a night's sleep, and again 1 and 4 hours after they had begun to perform moderate physical activity. Another 18 RA patients remained in bed and blood was sampled at the same time periods.