Synthesis of underpolymerized hyaluronic acid by fibroblasts cultured from rheumatoid and non-rheumatoid synovitis.

Fibroblast cultures were started from synovial tissue of normal controls and patients with seronegative and seropositive rheumatoid arthritis, juvenile rheumatoid arthritis and chronic non-rheumatoid synovitis. Glycosaminoglycan synthesis of the cultures was studied by metabolic labeling with 3H-glucosamine. Molecular weight of hyaluronic acid produced and secreted into culture medium by these fibroblast strains was studied by gel filtration in a Sepharose 2 B column. All fibroblast strains from joints with active inflammation produced hyaluronate with decreased molecular weight. The synthesis of underpolymerized hyaluronate thus appears to be a property of activated synovial fibroblasts common to rheumatoid and non-rheumatoid inflammation.