1. From the Division of Nephrology (J.H.I.), Department of Medicine (J.H.I., M.G.S., M.A.W.), and Department of Epidemiology and Biostatistics (M.G.S., M.A.W.), University of California, San Francisco; Section of General Internal Medicine, VA Medical Center, San Francisco, Calif (M.G.S., S.A., M.A.W.); and the Department of Nephrology and Clinical Immunology, University Hospital of the RWTH Aachen, Aachen, Germany (V.M.B., M.K.).