COMPLETE FREUND ADJUVANT INDUCES AN EARLIER AND MORE SEVERE ARTHRITISIN MRL-LPR MICE

A study was performed on the effect of CFA on the spontaneous arthriti s of MRL-lpr mice. The development of swelling and erythema was monito red for 1 mo after injecting 13- to 14-wk-old mice intradermally with CFA, at which time the histopathology of the joints and serologic resp onses to extracellular matrix proteins were investigated. In a series of six experiments, 67 to 82% of mice showed early clinical evidence o f arthritis in contrast to the low percentage observed in control anim als. Similarly, the histopathologic analyses on the CFA-injected mice indicated a significantly higher frequency of advanced histopathologic alterations, characterized by cartilage erosion and pannus formation. The serologic evaluation of the adjuvant-injected mice demonstrated a significant enhanced antibody production to type I and type II collag ens, DNA, and the Mycobacterium tuberculosis-positive control. This re producible adjuvant-enhanced model of murine arthritis will be extreme ly useful in evaluating experimental therapeutic regimes as the arthri tis is initiated earlier and exhibits an enhanced frequency and severi ty compared with the spontaneous arthritis seen in MRL-lpr mice.