Maternal immune memory and sex differences in living donor kidney transplant outcomes

Abstract

Females have higher rates of rejection and allograft failure not due to death compared to males. Offspring living kidney donor transplants provide an opportunity to assess the role of maternal immune memory in outcome differences between sexes. Among adult living kidney donor recipients in the Scientific Registry of Transplant Recipients from 2000 to 2018, the cumulative incidence of graft loss was higher in female compared to male recipients p <0.001. Among females, the adjusted hazard ratio (AHR) for graft loss was similar in offspring and non-offspring donor transplant recipients (AHR = 1.07, 95% confidence interval (CI), 0.94 -1.22, p =0.3) while male recipients of offspring donor kidneys had a lower risk of graft loss compared to non-offspring donor recipients (AHR = 0.87, 95% CI 0.77, 0.99, p = 0.03). Among females, offspring donor recipients had a higher adjusted odds ratio (AOR) for rejection, (AOR, 1.33, 95% CI 1.06, 1.67, p = 0.02) but among males, the odds of rejection were similar in offspring and non-offspring donor recipients (AOR, 1.15, 95% CI 0.95, 1.39, p = 0.14). The findings indicate a role for maternal immune memory in sex differences in kidney transplant outcomes that should be verified with further immunological studies.

Keywords: Graft Survival; Kidney Transplantation; Offspring Living Donors; Sex Differences.