Tatsuo Kawai, MD, PhD

Dr. Tatsuo Kawai is a professor of surgery at Harvard Medical School and the A. Benedict Cosimi Chair in Transplant Surgery at Massachusetts General Hospital. He is also director of the Legorreta Center for Clinical Transplantation Tolerance.

His clinical and research interests are primarily focused on development methods to induce immunological tolerance in organ transplantation. He was the first to report a consistent model for induction of renal allograft tolerance in nonhuman primates through a mixed chimerism approach. This and subsequent pre-clinical reports have extended this approach to the world’s first clinical trials for induction of renal allograft tolerance in HLA mismatched kidney transplantation. This is a seminal achievement of a clinical protocol leading to the first reproducibly successful induction of renal allograft tolerance in humans and was reported in the New England Journal of Medicine in 2008 and 2013. He was awarded the Martin Research Prize at MGH in 2009 and the New Key Opinion Leader Award by the Transplantation Society in 2010 for this work. Most recently, he was appointed an inaugural director of the MGH Legorreta Center for Clinical Transplantation Tolerance, which was built to become the world’s leading center dedicated to preventing organ rejection after transplant surgery without the use of lifelong immunosuppression.

In the field of xenotransplantation, Dr. Kawai achieved more than two years of survival of genetically engineered pig kidney xenografts in nonhuman primates (Nature, 2023), representing a major milestone toward clinical application. Building on these preclinical successes, he performed the world's first transplantation of a kidney from a pig with 69 genomic edits into a living patient with end-stage renal disease in March 2024. Although the patient died from an unrelated cardiac event on postoperative day 52 without evidence of rejection, the case was subsequently reported in the New England Journal of Medicine (2025). Since then, his team has performed four additional clinical kidney xenotransplants and achieved the longest reported kidney xenograft survival to date.

Education & Training

• Fellowship: Massachusetts General Hospital, Transplant, 2001
• Residency: Tokyo Women's Medical University, Surgery, 1987
• Residency: Kawasaki Municipal Hospital, Surgery, 1984
• Internship: Tokyo Women's Medical University, 1982
• Medical Education: Nihon University, 1981

Languages Spoken

• Japanese
• English

Age Group Treated

• Adults