Effect of CF101 and prophylactic or therapeutic MTX treatment on AIA rats. Rats were injected subcutaneously at the tail base with 100 μl of a suspension composed of incomplete Freund's adjuvant and 10 mg/ml heat killed Mycobacterium tuberculosis. (a) Clinical score. Combined treatment with MTX (prophylactic treatment) + CF101 yield significantly lower values than treatment with each of the agents alone; also, all treatments yielded lower scores than control group. (b) The clinical score with combined therapeutic MTX treatment + CF101 was significantly lower than that in the other groups. (c, d) Morphopathological score. In AIA animals complete distruction of the cartilage and the bone, as well as severe inflammation in the hind paws, was noted. Treatment with a combination of MTX and CF101 preserved the normal features of the paw. AIA, adjuvant-induced arthritis; MTX, methotrexate.