Donor-recipient weight and sex mismatch may contribute to kidney transplant failure

March 30, 2017

HighlightsWashington, DC (March 30, 2017) -- A new study indicates that the success of a kidney transplant may rely in part on a kidney donor's weight and sex, factors that are not typically considered when choosing a recipient for a deceased donor kidney. The findings, which appear in an upcoming issue of the Clinical Journal of the American Society of Nephrology (CJASN), suggest that changes may be needed to current immunology-based protocols that match donors and recipients.

Previous research has shown that there may be a higher risk of kidney transplant failure if a kidney donor is smaller than the recipient, perhaps due to increased strain on the relatively smaller transplanted kidney. Very few studies have investigated outcomes associated with donor and recipient weight mismatch, however. There is also a suggestion that sex mismatch between kidney donor and recipient may lead to worse outcomes post-transplant, but studies have generated conflicting results.

To investigate these issues, a team led by Amanda Miller, MD and Karthik Tennankore, MD (Dalhousie University and the Nova Scotia Health Authority, in Canada) examined whether receiving a kidney transplant from a smaller donor of the opposite sex would impact a recipient's transplant outcomes. The researchers analyzed information on a cohort of US deceased donor recipients between 2000 and 2014 who were listed in the Scientific Registry of Transplants Recipients. Over a median follow-up of 3.8 years, 21,261 of 115,124 kidney transplant recipients developed transplant failure.

After accounting for other transplant variables, the researchers demonstrated that if a kidney transplant recipient was >30 kg (66 pounds) heavier than the donor, there was a 28% higher risk of transplant failure compared with equally weighted donors and recipients. If the kidney was from a smaller donor of the opposite sex, the relative risk of transplant failure was further elevated to 35% for a male receiving a kidney from a female donor and 50% for a female receiving a kidney from a male donor. This risk is similar to that observed when a recipient receives a kidney transplant from a donor who has diabetes, a known risk factor for kidney failure.

"This study is extremely important because we have shown that when all else is considered, something as simple as the combination of a kidney donor's weight and sex is associated with a marked increase in kidney transplant failure," said Dr. Miller. "While more research is required before including these variables in a recipient matching strategy, this study highlights the importance of donor and recipient matching above and beyond current immunology-based protocols."

In an accompanying editorial, Bethany Foster, MD, MSCE and Indra Gupta, MD (McGill University) noted that while matching for sex and body size in organ allocation algorithms deserves consideration, this idea must be approached with a great deal of caution. It would require complex matching, and special care would have to be taken to avoid disadvantaging larger recipients. "Restricting transplant options by prioritizing sex matching may also lead to longer waiting times," they wrote. "Females with a large body size would be particularly disadvantaged by an approach that favoured allocation of sex- and body-size matched kidneys."
-end-
Study co-authors include Bryce Kiberd, MD, Ian Alwayn, MD, and Ayo Odutayo, MD.

Disclosures: The authors reported no financial disclosures.

The article, entitled "Donor-Recipient Absolute Weight and Sex Mismatch and the Risk of Graft Loss in Renal Transplantation," will appear online at http://cjasn.asnjournals.org/ on March 30, 2017, doi: 10.2215/CJN.07660716.

The editorial, entitled "Donor Quality in the Eye of the Beholder: Interactions Between Non-immunologic Recipient and Donor Factors as Determinants of Graft Survival," will appear online at http://cjasn.asnjournals.org/ on March 30, 2017.

The content of this article does not reflect the views or opinions of The American Society of Nephrology (ASN). Responsibility for the information and views expressed therein lies entirely with the author(s). ASN does not offer medical advice. All content in ASN publications is for informational purposes only, and is not intended to cover all possible uses, directions, precautions, drug interactions, or adverse effects. This content should not be used during a medical emergency or for the diagnosis or treatment of any medical condition. Please consult your doctor or other qualified health care provider if you have any questions about a medical condition, or before taking any drug, changing your diet or commencing or discontinuing any course of treatment. Do not ignore or delay obtaining professional medical advice because of information accessed through ASN. Call 911 or your doctor for all medical emergencies.

Since 1966, ASN has been leading the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients. ASN has nearly 17,000 members representing 112 countries. For more information, please visit http://www.asn-online.org or contact the society at 202-640-4660.

American Society of Nephrology

Related Kidney Transplant Articles from Brightsurf:

The effects of social determinants of health on kidney transplant candidates
Social determinants of health are associated with patient-reported outcomes in adults who are eligible to undergo kidney transplantation evaluations.

Tailored education system to benefit kidney transplant patients
Researchers find their computer-tailored education system, 'Your Path to Transplant' increases knowledge and readiness to pursue kidney transplant.

Kidney transplant, the cost of accounting for patients' preferences
Taking into account patients' preferences can help speed up the organ allocation process and improve the life quality of the recipients, as shown by a joint study conducted by Ca' Foscari University and the University of Padua

New hope for kidney revival for transplant
Cell therapy delivered directly to the kidney can revive a 'marginal' organ, improving function and could offer new hope for providing more kidneys for transplant.

Are kidney transplant patients at higher risk? The European experience
The risk of death is relatively high in kidney transplant patients admitted to hospital with COVID-19.

The economic burden of kidney transplant failure in the United States
A recent analysis published in the American Journal of Transplantation estimates that for the average US patient who has undergone kidney transplantation, failure of the transplanted organ (graft failure) will impose additional medical costs of $78,079 and a loss of 1.66 quality-adjusted life years.

Mixed chimerism improves long-term kidney transplant outlook
Mixed chimerism - the continued mixing of donor and recipient blood cells following a transplant of blood progenitor cells - could improve outcomes for kidney transplant recipients, according to a new clinical study in about 50 patients.

Kidney paired donation is an excellent option for transplant candidates
An analysis compared transplant recipients who received kidneys through national kidney paired donation and those who received kidneys from other living donors (such as relatives, friends or other paired exchange mechanisms).

Mediterranean diet may help preserve the kidney health of transplant recipients
In a study of kidney transplant recipients, those with higher adherence to the Mediterranean diet were less likely to experience kidney function loss.

New blood test can detect rejection by antibodies after kidney transplant
A group of European scientists led by KU Leuven has found a biomarker that can identify patients with symptoms of kidney rejection symptoms after a transplant as a result of antibodies.

Read More: Kidney Transplant News and Kidney Transplant Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.