Dr. Weinstein is Clinical Professor of Medicine, Loma Linda University (Rheumatology Division) and Clinical Professor Emeritus of Medicine, Georgetown University Medical Center. He is board certified in Rheumatology and Diagnostic Immunology. He graduated the University of Toronto Medical School and trained in internal medicine and rheumatology in Toronto and at the Hammersmith Hospital in London, England. His last academic position was Rheumatology Division Chief and Associate Chairman of Medicine, Washington Hospital Center in DC., a Georgetown University affiliate. Dr Weinstein is Master of the American College of Rheumatology and Fellow of the Royal College of Physicians of the United Kingdom. His areas of academic interest include clinical, laboratory and treatment studies systemic lupus erythematosus, as well as Lyme disease. He has a long standing clinical and research interest in the use of complement and its split products in SLE. He has authored/co-authored over 250 clinical and research papers, chapters, reviews, and abstracts of scientific presentations. Although retired since 2017, Dr Weinstein continues to teach and do clinical research in rheumatology at Loma Linda University in California.

Primary appointment as Professor in the Department of Laboratory Medicine & Pathology and Director of the Immunology Division and the Clinical Immunology Laboratory, with secondary appointment as Adjunct Professor in the Division of Rheumatology, Department of Medicine at the University of Washington, Seattle. Background in autoimmune test method evaluation and development. Serves on the College of American Pathologists (CAP) Diagnostic Immunology & Flow Cytometry Committee, which provides oversight for external quality assessment for a majority of US laboratories; the Autoantibody Standardization Committee; and the American College of Rheumatology Committee on Rheumatologic Care. His primary clinical focus is care of patients with systemic sclerosis as well as other autoimmune rheumatic diseases.