Rheumatoid arthritis and osteoarthritis synovial fluid effects on primary human endothelial cell cultures

Since vascular proliferation may be important in the pathogenesis of rheumatoid arthritis (RA) and/or osteoarthritis (OA), this study examined the induction of angiogenesis by these synovial fluids (SF). Four of 11 (36%) RA and 2 of 6 (33%) OA SF caused early morphological changes in human endothelial cell cultures. SF from 7 of 11 (63%) RA and 4 of 8 (50%) OA patients resulted in the late formation of tabular networks morphologically resembling capillaries observed in vivo. Early morphological changes in cultures were associated with a significantly (p less than 0.05) longer duration of disease in patients with RA. Factors present in the SF of RA and OA patients may play a role in the excessive vascularization which often occurs in these arthropathies.