AASLD:Men may be higher-quality liver donors than women

AASLD: Men Make Better Liver Donors

By Kristina Fiore , Staff Writer, MedPage TodayPublished: November 01, 2010Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston.

BOSTON -- Men may be higher-quality liver donors than women, potentially a result of differences in life expectancy and causes of death, researchers said here.

Males receiving an organ from females were at an increased risk of graft failure, Norah Terrault, MD, MPH, of the University of California San Francisco, and colleagues reported at the American Association for the Study of Liver Diseases meeting here.

"This likely reflects national gender differences in life expectancy and causes of death," Terrault said during an oral presentation here. "Life expectancy is longer for women, and they're more likely to suffer a stroke, while men are more likely to experience a traumatic incident."
Prior studies have suggested an increased risk of graft loss in gender-mismatched liver transplant recipients.
While donor factors strongly impact outcomes, gender is not currently one of seven major characteristics factored into risk score, which includes age, race, and cardiac or stroke death.
So to evaluate gender differences in donor quality and the effects on the association between donor-recipient gender mismatch and graft loss, the researchers assessed the records of 28,222 patients who had primary single-organ liver transplant in the U.S. between March 1, 2002 and Dec. 31, 2007.
Male recipients were less likely than female recipients to receive a gender-mismatched graft (37% versus 50%, P<0.001).
The researchers found that, in general, recipients of a gender-mismatched graft were at increased risk of graft loss (OR 1.11, 95% CI 1.06 to 1.16, P<0.001).
Yet that relationship appeared to be driven by female-to-male donation.
Compared with male-to-male matched transplants, female-to-male mismatch was associated with a significant 17% higher risk of graft loss and lower graft survival in univariate analyses (95% CI 1.11 to 1.24, P<0.001).
That risk was also significantly higher compared with all other donor-recipient gender pairings, Terrault said.
Women had no significant effects if they received a liver from a man, she said.
Control for multiple significant donor factors, however, completely mitigated the effects of a female-to-male gender mismatched organ.
In fact, Terrault said, female-to-female donation appeared to be protective in that scenario, with a 14% decreased risk of poor outcomes -- further indication that gender is not a direct risk factor for post-transplant outcomes.
She noted that the dominant factors influencing this effect were donor age and donor height. Female donors are, on average, eight years older and 13 cm shorter than men.
They're also twice as likely to die from stroke, while male donors tend to tie in traumatic accidents, indicating male organs may be healthier.
Terrault and colleagues concluded that donor quality differs significantly between men and women, and the donor risk index -- used by hepatologists to predict post-transplant success -- is significantly higher in women.
The differences in donor quality -- rather than donor-to-recipient gender mismatch -- are predictive of graft loss, likely a result of national gender differences in life expectancy and death.
"We need to focus on strategies to reduce the negative effects of unfavorable donor factors on post-transplant outcomes," Terrault said.
The researchers reported no conflicts of interest.
Primary source: American Association for the Study of Liver DiseasesSource reference:Lai JC, et al "Donor quality differs significantly between female and male donors" AASLD 2010; Abstract 67.