New research suggests sex-matching kidney donors and recipients may results in better outcomes. The report published in The Lancet found females who received a male donor kidney had higher rates of rejection and organ failure compared to other donor/recipient combinations.

Researchers believe females who receive a male kidney have an immunological H-Y effect (the male Y chromosome-encoded histocompatibility antigen) that extends to 10 years following the transplant. There is also speculation that since male kidneys are larger and have a higher number of nephrons (the basic structural unit of the kidneys), they may be a better match for male recipients. Women may not need as many nephrons and could benefit from a female donor kidney.

This article originally appeared in the August 2008 issue of Kidney Transplant Today.