UC Davis study finds that girls are less likely than boys to be placed on kidney transplant wait list

Physician with child and parent © iStockphoto
A new study shows that girls are significantly less likely than boys to be placed on a waiting list for kidney transplants, leading investigators to encourage clinicians to pay close attention to the transplant evaluation process and ensure that girls are given equal opportunities to receive transplants.

Posted April 27, 2011

A large study of children awaiting transplantation conducted by researchers at the UC Davis School of Medicine has found that girls are significantly less likely than boys to be placed on the waiting list to receive a new kidney.

The study, published in the journal Pediatric Transplantation, found that among children and young adults under 21 years of age starting dialysis, girls were 22 percent less likely than boys to be placed on the waiting list for a new organ.

Earlier research by UC Davis found that the sooner a child with advanced chronic kidney disease receives a new kidney, the better their long-term health and the longer the life of the organ.

“If the goal is to get them transplanted as soon as possible, then they need to be wait-listed as soon as possible,” said Stephanie Nguyen, assistant professor of pediatric nephrology at the UC Davis School of Medicine and the study's lead author. “The longer they’re waiting for a transplant, the worse their outcomes will be,” she said.

Nguyen said the study is a clarion call for clinicians to pay close attention to the transplant evaluation process and to ensure that girls are given opportunities to receive transplants as quickly as possible.

Dr. Stephanie Nguyen © UC Regents“If the goal is to get them transplanted as soon as possible, then they need to be wait-listed as soon as possible.”
— Stephanie Nguyen

For the study, UC Davis researchers reviewed data from approximately 4,473 patients whose health information was included in the North American Pediatric Renal Trials and Collaborative Studies database, a large, voluntary collaborative effort of 150 renal treatment centers in the United States, Canada, Mexico and Costa Rica.

The study found that girls were less likely to have been placed on the wait list to receive a new kidney at dialysis initiation, six months after starting dialysis and even 12 months after starting dialysis.

The study found that there were no other readily apparent factors that would account for girls not being wait-listed as frequently as boys, such as medical reasons or family preference. The study also notes that girls were less likely to have a living-related donor and also were less likely to have pre-emptive transplants than boys.

Girls are less likely than boys to be on the transplant wait list, even after adjusting for multiple confounding factors, such as age, race or ethnicity, underlying diagnosis and time of follow up. The reason most often given for why girls were not placed on the wait list at every point in time was that their “work-up was in progress.”

In December 2010, researchers at UC Davis published a study that found that the longer a child is on dialysis while awaiting a kidney transplant, the greater the likelihood that he or she will experience graft failure and organ rejection once they do receive a kidney transplant.

Dr. Lavjay Butani © UC Regents“Children who face kidney transplant fare best when they receive the organ without undergoing dialysis.”
— Lavjay Butani

The lead author for that study, Lavjay Butani, professor and chief of pediatric nephrology in the UC Davis School of Medicine, said that the findings suggest that, as is the case in adults, whenever possible children should not be placed on certain types of dialysis prior to transplantation and that the duration of dialysis should be minimized.

“Children who face kidney transplant fare best when they receive the organ without undergoing dialysis,” Butani said. “The longer the dialysis prior to the operation, the worse is the survival of the kidneys.”

The study, “The Effect of Pre-transplant Dialysis Modality and Duration on Long-term Outcomes of Children Receiving Renal Transplants,” was published in December 2010 in the journal Transplantation. It also suggests that children should be wait-listed for transplant immediately.

UC Davis Medical Center © UC RegentsUC Davis Medical Center was rated among the top U.S. hospitals for kidney transplantation by HealthGrades, a leading, independent health-care ratings organization.

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“The study by Dr. Nguyen and her group poses important questions that need to be addressed, to better explore and understand the reasons behind this gender difference in access to organ transplants and to determine if there are biological factors that may lead to a more time-consuming work-up to prepare girls for a transplant. In the absence of such considerations, it is the responsibility of all health-care providers treating this population to facilitate rapid transition of all children who are dialysis-dependent toward successful transplantation,” Butani said.

Other study authors include Karen Martz and Don Stablein of The EMMES Corporation and Alicia Neu of The Johns Hopkins University.