Peter Kerkhof, PhD, presents his poster, “Sex-Specific Aspects in Cardiac Transplantation Evaluated by Left Ventricular Size in Male and Female Recipients” at Experimental Biology 2018. Credit: Nathalie Fuentes

Whether you are male or female can play a role in your health when it comes to how well you recover and thrive after an organ transplant. Because donated organs are in high demand, the sex of the donor is not taken into consideration when assessing compatibility. However, men and women who receive donated organs can respond differently after transplantation, including in cases when the immune system rejects the transplanted organ. For some people, organ rejection may be influenced by the sex of the donor.

The influence of biological sex on transplant outcome has not been thoroughly studied—even as more than 3,000 people in the U.S. are waiting for a heart transplant on any given day. Peter Kerkhof, PhD, and colleagues at VU University Medical Center in the Netherlands evaluated current knowledge about the impact of biological sex differences in heart transplantation and explored why there is a discrepancy between rejection rates for male and female recipients. Kerkhof presented his team’s research at Experimental Biology 2018.

The researchers analyzed computer tomography scans of 94 patients who had a heart transplant. Forty percent of the transplanted hearts were from male donors, and 60 percent were from females. The research team discovered that the left ventricle—which supplies most of the heart’s pumping power and is essential for normal function—in transplanted hearts is able to adapt to the new body in size and pumping power, even if the recipient was of the opposite sex.

The researchers saw evidence of this adaptation in the ejection fraction of the heart recipients. Ejection fraction compares the amount of blood in the heart to the amount of blood pumped out and was found to be smaller in all female recipients, even those with male donor organs. The smaller ejection fraction in women is similar to what occurs in healthy women when compared to men. Now more research is needed to learn about the mechanisms responsible for sex-specific adaptation in heart transplant recipients.

Nathalie Fuentes is a PhD candidate in the biomedical sciences program at Penn State College of Medicine. Her studies in Dr. Patricia Silveyra’s lab include the development of sex-specific therapies to treat lung diseases, sex differences in asthma-related lung inflammation triggered by ground-level ozone and the role of male and female sex hormones in lung disease. Nathalie is originally from Caguas, Puerto Rico.

Nathalie served as a meeting blogger for Experimental Biology 2018.