Adult Hemolytic Uremic Syndrome with Renal Arteriolar Deposition of IgM and C3

Abstract

Hammar, Samuel P., Bloomer, H. Allan, and McCloskey, Donald: Adult hemolytic uremic syndrome with renal arteriolar deposition of IgM and C₃. Am J Clin Pathol 70: 434–439, 1978. Two cases of idiopathic adult hemolytic uremic syndrome in which deposits of IgM and C₃ were identified in renal arterioles showing fibrinoid necrosis are reported. Fibrin was also identified in the lumina of the involved vessels, but there was no lab-oratory evidence of disseminated intravascular coagulation. In both cases, serum C₃ was decreased and C₄ was normal, suggesting involvement of the alternate pathway of complement activation. These two cases suggest that in some instances the adult hemolytic uremic syndrome may be immunologically mediated, and that renal vascular thrombosis is a secondary phenomenon.