Revolutionary implant detects organ rejection weeks in advance

By Jim Leffman via SWNS

A device that can spot early signs of rejection in transplanted organs has been successfully trialed.

The tiny wireless implant senses the warning signs of rejection three weeks before current methods, making it easier to save the organ.

It works by continuously monitoring the organ and sending an alert to a phone or tablet if the temperature of it changes.

Current methods of detecting rejection are intermittent, imperfect and sometimes invasive and it can still happen decades after transplant.

The device, created by Northwestern University researchers in the US, is described in the journal Science.

At just 0.3 centimeters wide, 0.7 centimeters long and 220 microns thick, it is smaller than a pinky fingernail and about the width of a single hair.

It contains a highly sensitive thermometer, which can detect incredibly slight (0.004 degrees Celsius) temperature variations on just the kidney as well as monitoring blood flow.

The sensors are connected to a tiny package of electronics including a miniature coin cell battery for power which sit next to the kidney and use Bluetooth to stream data continuously.

The team used rats to test the ultrathin soft implant device, which sits directly on a transplanted kidney.

It detects temperature irregularities associated with inflammation and other body responses that arise with transplant rejection.

The extra three weeks it gives could help with early intervention, increasing the odds of preserving donated organs which are scarce and in high demand.

Rejection is often silent and patients might not experience symptoms, making this early warning device crucial.

Around 2,800 people receive a transplanted kidney in the UK every year with about another 5,000 waiting for a suitable organ.

Dr. Lorenzo Gallon, a Northwestern Medicine transplant nephrologist, who led the clinical portion of the study said: "I have noticed many of my patients feel constant anxiety not knowing if their body is rejecting their transplanted organ or not.

“They may have waited years for a transplant and then finally received one from a loved one or deceased donor.

"Then, they spend the rest of their lives worrying about the health of that organ. Our new device could offer some protection, and continuous monitoring could provide reassurance and peace of mind.”

Northwestern’s John Rogers, a bioelectronics pioneer who led the device development, added: “If rejection is detected early, physicians can deliver anti-rejection therapies to improve the patient’s health and prevent them from losing the donated organ.

“In worst-case scenarios, if rejection is ignored, it could be life threatening. The earlier you can catch rejection and engage therapies, the better. We developed this device with that in mind.”

At the moment, the easiest way to monitor kidney health is through measuring certain markers in the blood.

By tracking the patient’s creatinine and blood urea nitrogen levels, physicians can gain insight into kidney function but levels can change for a number of reasons, making the risk of false positives or negatives high.

The only alternative for detecting rejection is a biopsy, which is invasive and carries risks of multiple complications such as bleeding, infection, pain and even damage to nearby tissues.

Dr. Gallon said: “The turnaround time can be quite long, and they are limited in monitoring frequencies and require off-site analysis.

“It might take four or five days to get results back. And those four or five days could be crucial in making a timely decision for the care of the patient.”

First author Dr. Surabhi Madhvapathy added: “Each individual responds to anti-rejection therapy differently.

“Real-time monitoring of the health of the patient’s transplanted organ is a critical step toward personalized dosing and medicine.”

Because temperature increases accompany inflammation, the researchers targeted it for their device and when they tested it they noticed that the local temperature of a transplanted kidney increases as much as 0.6 degrees Celsius preceding rejection.

Dr. Madhvapathy added: “Organ temperature fluctuates over a daily cycle under normal circumstances.

“We observed abnormal higher frequency temperature variations occurring over periods of eight and 12 hours in cases of transplant rejection.”

The studies were conducted with kidney transplants but the researchers assume it could also work for other organs including the liver and lungs.

Dr. Joaquin Brieva, a Northwestern Medicine dermatologist not involved in the study has transplanted kidneys and has lost nine family members to kidney failure.

He said: "You’re walking a tightrope of anxiety about infections, complications from the drugs, various side effects and rejection of the kidney.

"Having this device would be reassuring.

“It can pick up any sudden changes in the kidney transplant and detect acute rejection, which currently gives no warning signs.”