Studies of hyaluronic acid in rheumatoid arthritis.

It has previously been shown that in most joint diseases changes occur in the hyaluronic acid in the joint fluid. In diseased fluids the hyaluronic acid has a considerably lower degree of polymerization than in normal fluids or in uncomplicated traumatic effusions (Sundblad, 1953). The hyaluronic acid changes are especially marked in rheumatoid arthritis. We recently demonstrated (Sundblad, Egelius, and Jonsson, 1954) that the clinical response to the intra-articular injection of hydrocortisone is regularly accompanied by an often complete restoration to normal of the hyaluronic acid changes. It appeared to us that determination of the degree of polymerization of the hyaluronic acid might provide a convenient objective record of the effects of therapy in joint diseases. The present study includes comparative tests with hydrocortisone acetate, hydrocortisone tertiary-butylacetate and other forms of local or systemic therapy. A brief discussion of the nature of the hyaluronic acid changes and their relation to certain clinical and laboratory data is also given.