Figure 3
The disease visual score correlates with histological changes in the affected joints. (a) A representation of ankle joint in wild type mouse at 10 weeks of age showing no evidence of synovitis or bone erosion; (b) A representation of a non-inflamed ankle joint in Balb/c IL1ra-/- mouse at 10 weeks of age showing no evidence of synovitis and bone erosion; (c) A representation of inflamed ankle joint in Balb/c IL1ra-/- one week after appearance of visual swelling of the joint demonstrating extensive infiltration of the synovium by inflammatory cells and pannus, like synovial proliferation but no bone erosion; (d) A representation of inflamed ankle joint in Balb/c IL1ra-/- mouse affected by swelling of the ankle for five weeks as determined by visual inspection, showing synovitis and erosion of bone by osteoclasts (Oc) within the pannus-like synovial proliferation. Black arrows indicate synovium, * joint surface, a continuous black line demonstrates the interface between the synovium and bone and joint surfaces. All figures are of haematoxylin and eosin-stained paraffin-embedded sections, original magnifications ×200.