A study by the University of Maryland turned the lights on for heart transplant patients and the doctors struggling to find the right medications to keep those hearts beating.
“Until these genes were discovered, we essentially were shooting in the dark,” said lead researcher Dr. Mandeep Mehra.
The test screens patients? blood for traces of genes that regulate the immune system. Researchers tied two of those directly to the rejection of organ transplants.
With the new test, “we can find traces of the immune response in the blood weeks and months before rejection becomes evident,” said Mehra.
He presented his findings Wednesday at the American Heart Association Scientific Sessions in Chicago.
Heart transplants are the fourth most common transplant operation in the U.S., according to the National Institutes of Health, with more than 2,200 operations per year. Healthy hearts can only be taken from an organ donor who is brain-dead but on life support, and the recipient must be heavily monitored following the operation for related infections and organ rejection.
“The phenomenon of heart transplant is nothing more than fighting nature,” Mehra said. “You?re taking someone?s heart tissue and putting it in another person, in an alien environment. Then you use a lot of immune suppressants” to keep the heart alive.
But finding the actual dosage of those suppressants ? called corticosteroids ? was never an exact science.
Patients visit the hospital 15 times in thatfirst year so doctors can remove a small sample of the new heart tissue and check it for inflammation, Mehra said. Doctors start immune suppressants at the highest dosage, then gradually reduce it until they find a balance for that particular patient.
To find the genetic markers that could predict this immune response more accurately, Mehra examined 74 transplant recipients, including 28 who developed moderate to severe rejection reactions, according to the research abstract provided by the University of Maryland, Baltimore.
Researchers examined 55 genes known to react to steroids, and found at least two that “turned on” in the patients with the worst symptoms of rejection.
University of Maryland spokesman Bill Seiler said the research points the way to more effective balancing of medications for transplant recipients, possibly reducing side effects of corticosteroids as well as the number of unnecessary heart biopsies.
