Success Story

March 10, 2020   I   Jola Glotzer

Making organs better for transplant

CBC Scholar Alum Greg Tietjen from UChicago, now Assistant Professor at Yale, researches new ways to help patients get the organs they need

Congratulations to Greg Tietjen, Assistant Professor at Yale School of Medicine, for his recent interview on TV NEWS8 station.

Greg completed his Postdoctoral training in the Department of Bioengineering at Yale University in the lab of Mark Saltzman prior to joining Yale School of Medicine, Department of Surgery, Section of Transplantation and Immunology. He earned his PhD in Biophysics at the University of Chicago working jointly with Ka Yee Christina Lee — current UChicago Provost, back then Professor in the Department of Chemistry — and Erin Adams, Professor in the Department of Biochemistry and Molecular Biology. Throughout all levels of his training, Greg’s emphasis has been on integrating multiple diverse disciplines to forge new scientific pathways. The focus of Dr. Tietjen’s current research is on adapting isolated organ machine perfusion, a recently developed innovation in clinical transplant, for use as a model system to engineer vascular-targeted nanomedicines. The ultimate goal of the Tietjen lab is to use the organ perfusion model to develop new therapeutic paradigms for use in organ transplant, while simultaneously establishing the theoretical 
foundation necessary for anatomic and cellular precision following 
systemic administration of targeted nanomedicines.

While a graduate student at UChicago, Greg was a recipient of a CBC Scholars Award (2012-2013). The CBC is proud to have supported Greg in his early scientific career, and delighted to report on his pursuit of new challenging and pioneering work at Yale. We wish him all the best in his future research endeavors!

February 17, 2020  |  Jocelyn Maminta  |  NEWS8

Life after organ transplant can be complicated but rewarding

Gregory Tietjen, PhD, Assistant Professor in the Yale School of Medicine, Department of Surgery, Section of Transplantation and Immunology comments on his research on organ transplant for NEWS8 (

NEW HAVEN, Conn. (WTNH)— Getting the call that a donor organ is available is the lifeline for thousands of men, women, and children on the national transplant waiting list. But life after transplant can lead to complications and surprising outcomes.

At a quick glance, it looks like lifelong friends reuniting. Don Pritchard and Christine Sicignano though were strangers nearly a year ago.

“We didn’t know each other beforehand,” said Pritchard.

Their bond grew when Christine donated a kidney after learning of Don’s critical need.

“It started with the kidney, yes,” said Pritchard. “In the beginning, I wanted to stay in touch because this woman saved my life.”

Meeting after surgery led to an unexpected deep friendship.

“She’ll text me a question, every now and then I’ll be like ‘hey what’s up’” said Prichard.

“Or he’ll text me ‘hey what’s up,’” said Sicignano.

It’s nearly a year out.

“At this point, it’s almost like it never happened because I feel normal,” said Pritchard.

But doctors tweaking the daily regimen of medication is Don’s new normal.

“I do have one of the anti-rejection meds that creates an elevated blood sugar in me so I do have insulin to take,” said Pritchard.

Christine is also monitored closely.

“They just check on me to make sure I’m okay,” said Sicignano.

Life dramatically improves for most patients after transplant but there is still a risk of complications like infection or rejection. And the complications multiply when they receive a cadaver organ.

“What the difference is in a deceased donor setting is that organs have to undergo a ton of stress,” said Dr. Greg Tietjen, Yale School of Medicine. “The storage on ice, traveling to another place. When it’s a living donor, that living donor is in the OR across the hall, the organ gets taken out and immediately transplanted in.”

Dr. Greg Tietjen at Yale School of Medicine is working with United Kingdom researchers in a groundbreaking study aimed at leveling the playing field.

“To be able to take the organ on the right and make it look like the organ on the left,” said Tietjen.

The problem?

“The blood is not being delivered throughout the organ,” said Tietjen.

Their focus on ‘impaired’ kidneys in the laboratory led to developing treatments that can remove clots and restore blood flow.

“It turns out that there was very basic drugs that are routinely used by clinicians now in the treatment of stroke that we could administer to these organs outside the body,” said Tietjen.

Plans are now underway for a Phase 1 clinical trial in a year or so with a limited number of patients.

“It would mean less complications post-transplant, shorter hospital stays, most importantly it will mean better access to organs,” said Tietjen.”Hopefully, make the experience of someone that receives the deceased donor organ like this much more similar to the experience of someone who receives a living donor.”

Dr. Tietjen points out the need for donors is just as critical for research as it is for transplant.

Christine Sicignano has no regrets.

“I want people to know how rewarding it is to be able to help somebody on this level,” said Sicignano.

It will be a year ago for Don’s transplant on March 26. Both Don and Christine live in Guilford.

Donate Life of American reports that since 1988, 750,000 transplants have taken place. And while 95% of Americans are in favor of being a donor, only 58% are registered.

Here in Connecticut, 46 percent of us are organ donors.

Adapted (with modifications) from NEWS8, by Jocelyn Maminta, published on February 17, 2020.

▸ Innovative Research, Potential Solutions to the Organ Transplant Problem
Yale Medicine

Featured CBC Community member:

Gregory Tietjen, UChicago

(Currently at Yale School of Medicine)


April 18, 2014
▸ How Immune Cells Tell Healthy and Diseased Cells Apart
CBC Scholar Gregory Tietjen first author on a recent PNAS publication