The effect of treatment with recombinant gamma-interferon on adjuvant-induced arthritis in rats

We have investigated the effects of recombinant rat gamma-interferon (rIFN gamma) on adjuvant-induced arthritis (AA). Lewis rats, inoculated in the left hind-paw with adjuvant (day 0), were given 10(5) U/rat of rIFN gamma daily (days 0 to 20), subcutaneously and intramuscularly on alternate days. rIFN gamma suppressed the secondary phase of swelling of both hind-paw on and after day 18 without influencing the earlier phases, both primary and secondary, of swelling. rIFN gamma also reduced the hind-paw bone lesions, the degree of splenomegaly, and the increase in erythrocyte sedimentation rate and plasma fibrinogen. These results indicate a new aspect of the regulatory role of IFN gamma in chronic inflammation.