Complete Freund's adjuvant suppresses the development and progression of pristane-induced arthritis in rats

The present study produced the novel finding that treatment with a nonarthritogenic dose of Complete Freund's adjuvant (CFA) before the onset of pristane-induced arthritis (PIA) could prevent the development of PIA. Surprisingly, treatment with nonarthritogenic and arthritogenic doses of CFA could almost cure the ongoing PIA. CFA treatment also suppressed pathological changes, such as inflammatory cell infiltration, pannus formation, bone destruction, and new bone formation. The lymph node cells of rats with PIA suppressed by CFA showed significantly increased mRNA expression of IFN-gamma but no significant changes in mRNA expression of IL-2, TNF-alpha, IL-4, and IL-5 compared with those of rats in the control groups. The possible mechanisms of the suppressive effect of CFA on the development and progression of PIA were discussed in terms of the anti-inflammatory roles of IFN-gamma, nitric oxide, and heat-shock protein-specific T cell responses. The present study found a new therapeutic implication for the treatment of rheumatoid arthritis.