Figure 4

Arthritis and cartilage damage in the knee joint on day 28 of prolonged arthritis. Mice received intra-articular injection on day 0 and three repeated intravenous boosts with antigen or PBS on days 7, 14, 21. (A–F) Representative histologic sections of knee joints from wild-type (WT) and transgenic (TG) mice treated with mBSA (AIA) and from non-arthritic wild-type control mice (CTR). Both inflammatory activity and cartilage damage were similar in TG and WT mice. (A–C) Haematoxylin and eosin staining. Arrows show synovitis and soft tissue inflammation. Bars = 100 μm. (D–F) Toluidine blue staining. Arrows show proteoglycan loss of articular cartilage. Bars = 100 μm. (G-H) Histopathology scores (G single, H total) in mBSA treated mice (AIA) on day 28 post intra-articular injection and three flare-up reactions. The knee joints of all mice were assessed as described in Materials and Methods. Bars show the mean ± SEM. Findings in arthritic wild-type and transgenic mice for single scores were compared by Mann–Whitney test. Total scores were compared between the 4 groups with adjustment for 4 parallel tests (α* = 0.0125). NS = not significant.