Hyaluronan: Clinical perspectives of an old polysaccharide

Abstract

The polysaccharide hyaluronan (hyaluronic acid) has been known since 1934. It has been detected in all vertebrate organs and fluids studied. The highest concentrations are found in loose connective tissues. For a long time hyaluronan was regarded as an inert filling material between the cells and attracted little attention. It was first used in clinical practice around 1970 for the treatment of joints in race horses and today intra-articular hyaluronan is given to patients with osteoarthritis. In 1980 hyaluronan also became a common device in intraocular surgery. In the last 15 years it has become apparent that hyaluronan is not at all an inert biological material. It is essential in foetal development; it binds specifically both to ceil surface proteins (receptors) and other matrix components; and its synthesis is activated in inflammatory conditions and during cell proliferation. New techniques to determine hyaluronan have revealed that it accumulates in blood and other body fluids during various pathological conditons and that it can be used for diagnostic purposes. Abnormal accumulation of hyaluronan in tissues may cause functional disturbances. This Minisymposium deals with the clinical consequences of our new knowledge.