Adjuvant polyarthritis. III. Evidence in support of viral etiology.

Intraperitoneal administration of a relatively small volume (0.2 ml) of plasma obtained from Sindbis virus--infected animals containing approximately 480 units of interferon/ml effectively suppressed the development of adjuvant arthritis. Similarly, administration of interferon (624 units/rat/day, ip) prepared in vitro by exposing rat embryo fibroblast culture to poly I:C in the presence of cycloheximide also suppressed the development of adjuvant arthritis without affecting the humoral or the cell-mediated immune response. The findings provide circumstantial evidence to the speculation that a virus or a virus-like organism plays a role in the pathogenesis of this disease.