Increased limb involvement in murine collagen-induced arthritis following treatment with anti-interferon-gamma

Abstract

SUMMARY: We have tested the effect of administering H22, a hamster neutralizing MoAb to murine interferon-gamma (IFN-γ) in collagen-induced arthritis. Mice were initTtuni7ed with human type II collagen in adjuvant on day 1 and boosted with soluble collagen on day 21. H22 was administered (250 μg. intraperitoneally) either during the induction of arthritis (on days 0, 6, 13 and 20) or around the time of discase manifestation (on days 21, 28, 35 and 42). Control mice received either an isotypc-matched non-neutralizing MoAb or saline. Both treatment regimes gave sitnilar results. Treattncnt with H22 did not signifieantly affect the incidence of arthritis, time of onset, degree of oedetiia. histopathologi-cal severity, or level of anti-type II collagen IgG. However, a highly signiticanl increase (P < 0·01) in the number of limbs affected by arthritis was observed in the H22-treated group, irrespective of whether the antibody was administered during the induction of arthritis, or during the time of clinical manifcstalion of disease. From these results it was concluded that anti-IFN-γ treatment caused an inerease in the niitnber of arthritic lesions, but did not affect the severity of each individual lesion.