1. From the Department of Medicine, Division of Nephrology, Georgetown University Medical Center, Washington, DC 20007, the Department of Pathology, University of Maryland, School of Medicine, Baltimore, MD 21201, and the Laboratory of Immunology and Laboratory of Clinical Investigation, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda MD 20014 (address reprint requests to Dr. Gelfand at the Nephrology Division, Georgetown University Hospital, 3800 Reservoir Rd...