SUBCUTANEOUS ADMINISTRATION OF HYALURONAN REDUCES THE NUMBER OF INFECTIOUS EXACERBATIONS IN PATIENTS WITH CHRONIC-BRONCHITIS

Hyaluronan (HA) is a high molecular weight glycosaminoglycan found in large amounts in the skin, joints, and other organs. Previous studies have shown that HA stimulates neutrophil functions both in vitro and i n vivo. The object of this study was to test the hypothesis that HA ad ministration subcutaneously might reduce the number of bacterial infec tions in humans with an increased susceptibility to such infections. F or this purpose we have studied 29 patients with chronic bronchitis an d recurrent acute exacerbations of their disease. The patients were ra ndomly separated into two groups. One group had HA for 6 mo followed b y 6 mo of placebo, and the other group started with placebo treatment followed by HA. The treatment periods occurred during two consecutive winter periods. HA-treated patients had significantly fewer acute exac erbations (p = 0.01) than did placebo-treated patients. Likewise the c onsumption of antibiotics and other signs of bacterial infections were reduced. In the crossover study the placebo-treated patients again ha d much higher numbers of acute exacerbations than did the HA-treated p atients (p < 0.0001). It is concluded that HA reduces the number of in fectious exacerbations in patients with chronic bronchitis, possibly b y enhancing cellular host defense mechanisms. HA is a new endogenous s ubstance that can be used to stimulate host defense reactions and redu ce the need of antibiotics. Before being recommended for clinical use, however, our results should be confirmed by further studies.