William S. Asch, MD, PhD

William Asch, MD, PhD, is a nephrologist who focuses on kidney transplantation and says he enjoys the challenge of a complicated case.

“I really like the puzzle of trying to figure out what is going on with a patient who has complex problems and helping them,” Dr. Asch says. “There is nothing more gratifying than taking someone who has been on dialysis for six weeks, six years, or 13 years and giving them a new kidney and seeing their life transform in the best of ways.”

Growing up, Dr. Asch says he pretty much knew he wanted to become a doctor. “I remember having profound respect for our family physician and seeing a microscope in his office and being really interested in that,” he says. “I was very interested in physics in high school but then settled into biological sciences with a focus on physiology in college.”

In addition to his medical degree, Dr. Asch has a doctorate degree in molecular biology, which ended up being a good fit at Yale, given the medical school’s strong history in laboratory-based nephrology research.

“For me, kidney transplantation is a great pairing of my interests in lab work, physiology, and physics,” he says. “And what I love is that there is an overlap with so many different fields that make my job so fascinating. Transplant nephrologists aren’t in a vacuum. We work closely with colleagues from infectious diseases, cardiology, and many other specialties.”

An active researcher, Dr. Asch is exploring the underappreciated neurocognitive impairment associated with tacrolimus, an immunosuppressant medication. “It’s challenging to study, but we have an eye on the possibility that some of our newest drugs might not have that same negative impact on cognition,” Dr. Asch says.