# The effect of donor–recipient sex matches on lung transplant survival: An analysis of the United Network for Organ Sharing database

## TL;DR

This study finds that matching donor and recipient sex improves lung transplant survival, especially for female recipients with female donors.

## Contribution

The study identifies that donor-recipient sex matching significantly affects lung transplant survival when controlling for size differences.

## Key findings

- FF (female to female) donor-recipient pairs had the longest survival times compared to other groups.
- After controlling for size, FF and MF (male to female) groups had better 5- and 10-year survival than FM (female to male).
- Female recipients may benefit more from female donor lungs of similar size.

## Abstract

To investigate the impact of donor–recipient (DR) sex matches on survival after lung transplantation while controlling for size difference in the United Network of Organ Sharing (UNOS) database.

We performed a retrospective study of 27,423 lung transplant recipients who were reported in the UNOS database (January 2005-March 2020). Patients were divided into groups based on their respective DR sex match: male to male (MM), male to female (MF), female to female, (FF), and female to male (FM). Kaplan–Meier curve and Cox regression with log-rank tests were used to assess 1-, 3-, 5-, and 10-year survival. We also modeled survival for each group after controlling for size-related variables via the Cox regression.

Kaplan–Meier curves showed overall significance at 1-, 3-, 5-, and 10-year end points (P < .0001). Estimated median survival time based on Kaplan–Meier analysis were 6.41 ± 0.15, 6.13 ± 0.18, 5.86 ± 0.10, and 5.37 ± 0.17 years for FF, MF, MM, and FM, respectively (P < .0001). After we controlled for size differences, FF had statistically significantly longer 5- and 10-year survival than all other cohorts. MF also had statistically significantly longer 5- and 10-year survival than FM.

When variables associated with size were controlled for, FF had improved survival than other DR groups. A female recipient may experience longer survival with a female donor’s lungs versus a male donor’s lungs of similar size.