CD55 and hemolytic-uremic syndrome: On lymphocytes CD55 expression was significantly higher in the HUS and HUS/N groups compared to HC (Fig. 1 E; 7824 and 7944 vs. 7246, p = 0.0638 and p = 0.0488) and the GI group (7824 and 7944 vs. 7252, p = 0.0233 and p = 0.0107 respectively).