Figure 1.

 Treatment with MTX or albumin coupled MTX (MTX-HSA) suppresses cartilage invasion and perichondrocytic cartilage degradation in the SCID mice model of human RA. SCID mice were co-implanted subcutaneously with human cartilage and RA SF. Thereafter, they were treated with intraperitoneal injections twice weekly of 0.9% NaCl (control, n = 5), or 1 mg/kg MTX (n = 9), or 1 mg/kg MTX-HSA (n = 6). After 4 weeks of treatment, the implants were analysed histologically (fig 2), and cartilage invasion by SF as well as perichondrocytic cartilage degradation were scored (*p<0.05; **p<0.01; error bars represent SEM).