Effect of post-treatment on joint swelling and lameness. Right knee joints of all sensitised rats were injected with antigen on Day 0. Treatment was commenced two days following arthritis induction. Knee widths (A, B) and gait scores (C, D) were then recorded for each rat and are displayed as a change in these parameters from point of treatment (Day 2). Treatment with the sPLA2I at both doses (5 and 10 mg/kg) resulted in a significant reduction in joint swelling (A) (P < 0.05; Days 3 to 14) and gait scores (C) (P < 0.05; Days 4, 10, 12). Treatment with the comparator drugs (leflunomide, infliximab and prednisolone) also resulted in significant reductions (P < 0.05) in joint swelling (B) and gait scores (D) although to a lesser extent than the sPLA2I (knee widths: leflunomide (Days 4 to 8), infliximab (Days 3 to 8), prednisolone (Day 10); gait scores: leflunomide (Days 6, 8), infliximab (Days 6 to 10),to prednisolone (Day 4)). Each data point represents the mean ± SEM.