Tissue samples from a QD ([B10.Q × DBA/1]F1) mouse immunized with matrilin-1 to induce relapsing polychondritis. (a) Section from the tracheal cartilage in the acute phase, showing inflammatory infiltrates and severe cartilage destruction. Cells detected in the infiltrates are macrophages, neutrophils, lymphocytes, and eosinophils. (b) Section from nasal septum, showing inflammatory infiltrates, fibrin deposition, and erosion of the cartilage. Staining with hematoxylin and erythrosine. Original magnification ×200.