Suppressive effect of a neutrophil elastase inhibitor on the development of collagen-induced arthritis.

A novel neutrophil elastase inhibitor, ONO-5046, was administered to BB/DR rats and DBA/1 mice immunized with type II collagen to study its effect on the development of collagen-induced arthritis (CA), an experimental model of human rheumatoid arthritis. ONO-5046 reduced the incidence as well as the severity of CA in both rats and mice. This suppressive effect on severity was correlated with improvement of the histological findings, particularly with reduced destruction of the articular cartilage. These results indicate that neutrophil elastase may play an important role in the pathogenesis of CA.