Leonard Calabrese is an American rheumatologist, an osteopathic physician, and an internationally recognized HIV/AIDS and hepatitis C researcher at the Cleveland Clinic.^[1][2][3] Calabrese is the vice chair of the Cleveland Clinic's Department of Rheumatic and Immunologic Diseases and the co-director of the Center for Vasculitis Care and Research, while also serving as director of the Cleveland Clinic's RJ Fasenmyer Center for Clinical Immunology.^[3][4][5] He is also a medical professor at the Cleveland Clinic Lerner College of Medicine.^[3][5] Over the course of his academic research career, Calabrese has authored more than 300 publications including book chapters and peer-reviewed journal articles.^[5][6]

Calabrese attended Cathedral Preparatory School in Erie, Pennsylvania then went on to complete his undergraduate education at John Carroll University in 1971.^[4] He subsequently went on to complete his medical education at the Kansas City University of Medicine and Biosciences' College of Osteopathic Medicine.^[4] He graduated with his Doctor of Osteopathic Medicine degree in 1975.^[3][4] After finishing medical school, he completed his internal medicine residency and rheumatology fellowship at the Cleveland Clinic.^[1][4]