Medical Staff

Brian Poirier, MD

Medical Director, Endocrine Sciences

Dr Poirier is a diplomate of the American Board of Pathology in anatomic and clinical pathology as well as in transfusion medicine.  He earned his medical degree from the University of Colorado Health Science Center in Denver, where he received the dean's recognition for academic excellence.  Dr Poirier has completed residencies in anatomic and clinical pathology at the University of California at Davis in addition to fellowships in surgical pathology and transfusion medicine.  He has worked with the nonprofit organization, Global Healing, and the Republic of Georgia's National Center for Disease Control on a plan to improve the safety of Georgia's national blood service.  He also provided a series of advanced transfusion medicine training programs at various medical centers throughout the Republic of Georgia.

Dr Poirier holds membership in the American Society for Clinical Pathology (ASCP), the College of American Pathologists (CAP), the AABB (American Association of Blood Banks), the American Society for Apheresis, and the American Society of Hematology.

Kelly Y. Chun, PhD

Vice President, Labcorp; Scientific Director, Endocrine Sciences

Dr Chun received her PhD in biochemistry from the Medical College of Wisconsin and trained as a postdoctoral fellow in laboratory medicine at Harvard Medical School. She has more than 20 years of experience in protein science and assay development and validation. She joined Esoterix in 2002 as a technical director. She oversees chemistry tests, endocrine immunoassays, and immunogenicity testing.

Over the years, Dr Chun has developed and validated a number of pivotal endocrine and autoimmune assays for pharmaceutical trial and clinical diagnostic use. She lectures on a national level and has authored articles and book chapters with a focus on endocrinology and immunogenicity. She is a member of the Endocrine Society, American Diabetes Association, and the American Association of Clinical Chemistry.

Brett Holmquist, PhD

Associate Scientific Director, Endocrine Sciences

Dr Holmquist is board certified by the American Board of Clinical Chemistry, a fellow of the National Academy of Clinical Biochemistry, licensed by the state of California as a clinical chemist, and certified as a New York State laboratory director. He earned his PhD in biochemistry and molecular biology from the University of California, Riverside.  He has worked for more than 25 years in the life science industry, including more than 12 years in the diagnostic laboratory industry. He is a member of the Endocrine Society, the American Society for Mass Spectrometry, the American Society for Clinical Pathology, the American Society for Clinical Laboratory Science, and the American Association of Clinical Chemistry.

Toni R. Prezant, PhD

Director of Molecular Genetics, Endocrine Sciences

Dr Prezant is board certified in clinical molecular genetics by the American Board of Medical Genetics and Genomics and is licensed in California and certified in New York State as a laboratory director. She earned her PhD in biology from the Massachusetts Institute of Technology. Dr Prezant has more than 12 years of clinical experience in molecular genetic testing and an extensive research background, including studies of mitochondrial DNA diseases and pituitary tumorigenesis. Dr Prezant develops and validates new tests for Endocrine Sciences’ molecular genetics laboratory. She is a member of the American Society of Human Genetics and the Association for Molecular Pathology.