Correlation between increased hyaluronan localized in arthritic synovium and the presence of proliferating cells. A role for macrophage-derived factors.
OBJECTIVE
To determine whether the increased levels of circulating hyaluronan seen in patients with arthritis also occur locally.


METHODS
Biopsy specimens of normal synovium and synovium from patients with various arthropathies were studied using histochemical and immunohistochemical staining procedures, to determine the tissue distribution of hyaluronan and infiltrating cells.


RESULTS
Hyaluronan was found in increased concentrations in inflamed tissues, and was co-localized in sites containing Ki-67+ cells. In vitro analyses showed that macrophage-released factors increased hyaluronan production by fibroblasts. Hydrocortisone inhibited this in vitro production of hyaluronan.


CONCLUSIONS
Edema and swelling seen in inflamed joints may be due to the presence of large amounts of hyaluronan. One possible mechanism of action of corticosteroids in the alleviation of acute joint inflammation may occur via the inhibition of hyaluronan production.
Wells
A F
AF
Department of Biology, University of South Florida, Tampa 33620.
Klareskog
L
L
Lindblad
S
S
Laurent
T C
TC
D001168:Arthritis / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism*; D007592:Joint Diseases / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D009000:Monocytes / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism; D013583:Synovial Membrane / Q000378:metabolism*; D013585:Synovitis / Q000473:pathology; D014018:Tissue Distribution
D006820:Hyaluronic Acid