Dr. Stephen W. Olson

Dr. C. John Sperati is an Associate Professor of Medicine at the Johns Hopkins University School of Medicine. His areas of clinical expertise include renal medicine. Dr. Sperati is Director of the Glomerular Diseases Fellowship Program since 2023 and formerly directed the Nephrology Fellowship Training Program from 2019 - 2025. He was the long-serving Firm Faculty Leader of the Barker Firm and has held leadership positions within the Osler Medical Residency training program. In addition, he co-directs the Johns Hopkins Osler Learning Initiative which brings the principles of medical residency training to executive education worldwide. He obtained his medical degree from The Pennsylvania State University College of Medicine and a Master in Health Science from the Johns Hopkins Bloomberg School of Public Health. He completed an internship and residency in Internal Medicine at the Johns Hopkins Hospital, followed by a year as an Assistant Chief of Service (chief resident). He subsequently pursued subspecialty training in nephrology at the Johns Hopkins Hospital and joined the faculty in the Division of Nephrology. Dr. Sperati’s clinical interests are in thrombotic microangiopathy including atypical hemolytic uremic syndrome (aHUS), complement-mediated kidney diseases including C3 glomerulopathy, glomerular disease such as glomerulonephritis (e.g., IgA nephropathy, MPGN) and nephrotic syndromes (e.g., FSGS, membranous, minimal change, amyloidosis, and others), and secondary and resistant hypertension (e.g., fibromuscular dysplasia, atherosclerotic renal arterial disease, hyperaldosteronism, and genetic hypertensive syndromes). He is the site principal investigator for clinical trials in glomerular disease, serves on editorial boards, and chairs the approval committee of the Longitudinal Knowledge Assessment for nephrology for the American Board of Internal Medicine. His clinical acumen and educational contributions have been recognized by induction into the Miller Coulson Academy of Clinical Excellence as well as the American Society of Nephrology Distinguished Educator Award in 2020. He has been recognized as a physician resource through the Atypical HUS Foundation, a NephCure glomerular disease specialist, an IgA Nephropathy Foundation specialist, and a Baltimore TopDoc. He is registered with the Florida Department of Health to perform telehealth services for patients in Florida. Dr. Sperati is rated as a Distinguished provider by MediFind in the treatment of D-Plus Hemolytic Uremic Syndrome. His top areas of expertise are Atypical Hemolytic Uremic Syndrome (aHUS), D-Plus Hemolytic Uremic Syndrome, Hemolytic-Uremic Syndrome, Glomerulonephritis, and Kidney Transplant.

Dr. Nada Alachkar is an associate professor of medicine at the Johns Hopkins University School of Medicine. Her areas of clinical expertise include incompatible kidney transplants, kidney transplants, nephrology and pancreas transplants. Dr. Alachkar earned her M.D. at Aleppo University Faculty of Medicine in Syria. She completed residencies at Aleppo University and Wright State University School of Medicine. She performed clinical fellowship in nephrology and transplant nephrology fellowship at Johns Hopkins University. Her research interests include recurrent glomerular diseases post kidney transplantation; in particular recurrent FSGS post transplant. Also, she is studying biomarkers in kidney transplants; outcome of living and deceased donor kidney transplant recipients with positive crossmatch; and responses to desensitization treatments and post-transplant outcome in highly sensitized patients. Dr. Alachkar is a member of the American Society of Nephrology and the American Society of Transplantation. Dr. Alachkar is rated as a Distinguished provider by MediFind in the treatment of D-Plus Hemolytic Uremic Syndrome. Her top areas of expertise are Focal Segmental Glomerulosclerosis, Atypical Hemolytic Uremic Syndrome (aHUS), D-Plus Hemolytic Uremic Syndrome, Kidney Transplant, and Splenectomy.

Daniel C. Brennan, M.D., joins the Johns Hopkins Division of Renal Medicine as professor of nephrology and medical director of the Comprehensive Transplant Center. Dr. Brennan’s areas of clinical expertise include transplant nephrology and renal disease. Prior to joining Johns Hopkins, Dr. Brennan was the Alan A. and Edith L. Wolff Professor of renal Diseases at Washington University and the Director of Transplant Nephrology at the Washington University School of Medicine. He received his undergraduate degree from Cornell College and earned his medical degree at the University of Iowa, where he completed a residency in internal medicine. He then completed research and clinical nephrology fellowships at Brigham & Women’s Hospital/Harvard Medical School. Dr. Brennan holds professional memberships at various organizations, including the American College of Physicians, the International Society of Nephrology, the American Society of Nephrology, The Transplantation Society, the American Society of Transplant Physicians and the American Society of Clinical Investigation. Dr. Brennan is rated as a Distinguished provider by MediFind in the treatment of D-Plus Hemolytic Uremic Syndrome. His top areas of expertise are Chronic Kidney Disease, Cytomegalovirus Infection, Cytomegalic Inclusion Disease, Kidney Transplant, and Pancreas Transplant.