SHIP deficiency causes Crohn's disease-like ileitis

Kerr, William G; Park, Mi-Young; Maubert, Monique; Engelman, Robert W

Rarely, ileitis spread by direct extension to other gastrointestinal sites, including in two mice where inflammation of the ileum extended via the mesentery to the colon wall ( figure 8A,B) , and in a third SHIP-deficient mouse where inflammation had spread to the gastro-oesophageal juncture ( figure 8C,D) . Draining mesenteric lymph nodes were often enlarged and inflamed in 33 of 53 (62%) of SHIP-deficient mice ( figure 8E,F ). An individual SHIP À/À mouse had inflammatory cellular thrombi in mesenteric veins and a granulomatous pulmonary consolidation comparable in composition to the ileitis in this case, suggesting that vascular thrombi and emboli may rarely develop as a consequence of CD-like ileitis in SHIP-deficient mice and may disseminate inflammation via haematogenous routes (figure 8GeJ). This pulmonary consolidation was distinct from that which occurs routinely in SHIP À/À and SHIP DIPDIP mice as an eosinophilic crystalline pneumonia (figure 9AeF).