Leslie J. DeGroot MD (“Les”) was born on a dairy farm in Fort Edward NY in 1928, dedicated his life to thyroid disease research and endocrinology and died soon after his 90th birthday, on October 23, 2018 in Nonquitt, Massachusetts, surrounded by his many loving grandchildren, children and his wife.

At the time of his death, he was a faculty member (Research Professor) at the University of Rhode Island, and member of the Institute for Immunology and informatics at the Downtown Providence campus of the University. While “Les” was well known for  his many important contributions to the field of endocrinology and thyroid disease, including improving the understanding of thyroid synthesis and its mechanism of action, iodine metabolism, thyroid cancer, and autoimmune thyroid disease, he is more widely known by physicians, endocrinology fellows, and online users as the editor of the online textbooks “EndoText” www.endotext.org and “ThyroidManager” www.thyroidmanager.org. These ‘living textbooks’ have evolved over the past 15 years to include more than 400 editors and authors. They are fundamentally important to the education of endocrinologists all over the world, many of whom would not have otherwise had access to the most recent information about the research pertaining to, and treatment of, endocrine diseases. The impact of this entirely volunteer-run website on the education of generations of physicians and researchers will be his most long lasting and important legacy.

Leslie J. De Groot was born on a dairy farm in Upstate New York, one of two children (his sister, Janice, died of leukemia in her early 20s). His mother, Fort Edward artist Frances (Orr) DeGroot and father, church deacon and farmer Henry De Groot provided strong moral support and physical sustenance while encouraging him to work hard and pursue a college degree. Leslie performed well at school, went to college early, and graduated from nearby Union College in 1948 at age 20. He then moved to New York City, earning his medical degree at Columbia University Medical School in 1952 and served as Intern and Resident at the Presbyterian Hospital, where he met the love of his life, Helen (Pond Searls). They were married in 1955 while he was working in Washington DC (with Monte Greer) at the National Cancer Institute (National Institutes of Health). After working at the NIH, Les and Helen opted to work as “medical missionaries” and moved to Laskergah, Afghanistan, serving the US Operational Mission to Afghanistan, helping to build and operate a hospital. In 1956 they returned home to settle in Winchester Massachusetts with their growing family. Les became a member of the John Stanbury Thyroid Unit, while completing his fellowship at Massachusetts General Hospital. He moved with Stanbury to the Massachusetts Institute of Technology in 1966 before being invited to become Professor of Medicine and Director of the Thyroid Study Unit at the University of Chicago in 1968 at the age 40.

Les was an ‘early adapter’ of new technologies throughout his life, always eager to learn about new concepts. Checkpoint inhibitors were his most recent source of fascination. He was involved in identifying radiation as a source of thyroid cancer in the 60’s and 70’s and then became involved in molecular biology in the early 1980s. He collected patient samples (early bio-banking) and mapped T cell epitopes in the 1990s and 2000s, exploring oral tolerance, gene therapy, and T cell epitopes in his pursuit of treatment for thyroid disease. He recognized the power of the world wide web and pioneered the publication of the online medical textbooks, developing two, EndoText (www.endotext.org) and Thyroid Manager (www.thyroidmanager.org) which still serve as an important source of current information on research and treatment of endocrine diseases for endocrinologists all over the world.

In 2005, he ‘retired’ to Brown University, continuing his research in the laboratory run by his daughter Annie, before moving with her in 2008 to the University of Rhode Island and becoming one of the first members of the Institute for Immunology and Informatics in downtown Providence at the age of 80. He remained the highly engaged editor of his online textbooks, continuing to travel to endocrinology conferences all over the world (often accompanied by Helen) even after retiring from active academic life at age 85. He shared his love of sailing with his children and racing crew, experimented with winemaking, contributed to local non-profits in South Dartmouth and Buzzards Bay, participated in the social activities at Nonquitt with a large circle of friends, and spent many lively hours at the dinner table, debating politics with his children and then his grandchildren.

He was an engaged and active mentor to a widespread diaspora of endocrinology fellows, many of whom have become leaders in endocrinology research and patient care. He was a loving and steadfast husband to Helen, an inspirational father to his children, artist Katie DeGroot, physician and researcher Annie De Groot (EpiVax, URI), Director of Development (Duffy) Elyse De Groot, orthopedic physician Henry De Groot, and nonprofit founder (ThirdPath) Jessica De Groot, and a generous grandfather to Niles, Zeno and Aminata, Matthew and Eliza, Phoebe, Genevieve, Henry and Catherine, Jocelyn, and Julian. Leslie J. De Groot was giant in research and at home, always innovating, endlessly working, always contributing. Now that he is finally at rest, he will be sorely missed.

In lieu of flowers, please send your memorial contributions to:

Buzzards Bay Coalition (Where Les loved to sail …save Buzzards Bay, for the next generation) http://www.savebuzzardsbay.org/

American Farmland Trust: https://www.farmland.org/ …because Les loved the Farm.

A memorial service will be held on in late November or early December at the Fort Miller Reformed Church in Upstate New York, please contact Dr.Annie.DeGroot [at] gmail.com if you are interested in attending.

For recorded videos of LDG: https://www.thyroid.org/portfolio/history-archives-interview/

For an extensive interview: https://www.endocrine.org/~/media/endosociety/files/about-us/sawin/lesliedegroot_trans.pdf?la=en