Gender Is Critical in Kidney Transplant

Data regarding as much as 200,000 kidney transplants done between 1985 and 2004, shows that gender is a key factor in this type of invasive procedure, kidneys from women received by men being unable to fully cope with their function due to their smaller size, while female recipients are much more likely to reject male kidneys due to gender specific chromosomes. The data was provided by the Collaborative Transplant Study, and analyzed by researchers of the Basel University Hospital and the Heidelberg University Hospital.

The Collaborative Transplant Study is the world's largest database related to the results of long-term organ transplants, led by Professor Dr. Gerhard Opelz, Medical Director of the Department of Transplant Immunology at the Institute of Immunology of the Heidelberg University Hospital. The results show that the transplant of a female kidney is very likely to fail, mostly because generally the organs are much smaller than in men and they contain less nephrons, thus are less efficient in filtering urine.

On the other hand, women receiving kidneys from men have a risk of rejection up to 10 percent higher than other donor-recipient combinations, even 10 years after the operation. "The higher rate of rejection is most likely caused by the gender-specific Y chromosome in men," said Professor Opelz. This is compensated however through the fact that men's kidneys are much more efficient than women's.

In Germany, and some other five states in Europe, organ transplants are coordinated through the Eurotransplant organ distribution computer center on criteria established by immunologists from the Heidelberg University Hospital. However, gender compatibility is unlikely to be included anytime soon as rejections related to the functions of gender specific chromosomes still need to be studied in detail.

Connie L. Davis of the University of Washington believes that transplanting same-gender organs only is not well justified yet, since even in transplants between donor and recipient of different genders the results are often good.