Litholink's Medical Staff Experts

John Asplin, MD

Medical Director and Laboratory Director

Dr Asplin is board certified in internal medicine and nephrology. He graduated with a BA from the College of the Holy Cross and obtained his medical degree from Emory University School of Medicine. Dr Asplin completed his residency in Internal Medicine at the University of Cincinnati Medical Center. He then spent three years in the Navy Medical Corps before doing his nephrology fellowship at the University of Chicago.

After fellowship, Dr Asplin joined the faculty at the University of Chicago Medical School, where he pursued clinical and research interests in kidney stone disease. In 2000, he joined Litholink Corporation as medical director, a position he continues to hold. Litholink became a subsidiary of LabCorp in 2007. At Litholink, Dr Asplin oversees the medical aspects of the kidney stone program, including creation of medical algorithms for interpretation of urine chemistries and providing consultation to physicians who have questions about their kidney stone patients. He provides medical support for the creation of Clinical Decision Support products and directs a busy research program focused on kidney stone disease. Dr Asplin continues his teaching duties at University of Chicago. Dr Asplin has published over 80 peer-reviewed articles, as well as numerous book chapters. He is on the editorial board of American Journal of Nephrology and Urolithiasis. 

Jennifer Ennis, MD

Medical Director

Dr. Ennis earned her MD at the University of Pittsburgh School of Medicine, and completed internal medicine and nephrology fellowship training at the University of Chicago Medical Center. She is board certified in internal medicine and nephrology.

Dr. Ennis joined Litholink/Labcorp as a medical director in 2009. She oversees the medical and clinical aspects of several of Labcorp’s clinical decision support offerings, including chronic kidney disease, cardiovascular disease, and diabetes.

Dr. Ennis is also a Clinical Assistant Professor of Medicine in the section of Nephrology at the University of Illinois at Chicago, where she sees patients and teaches medical students, residents, and fellows. She performs clinical research in chronic kidney disease and has authored several abstracts and peer-reviewed publications.

Dr. Ennis is a Fellow of the American College of Physicians and is a member of several other medical societies, including the American Society of Nephrology and the National Kidney Foundation.