Introduction to Sex Combinations in Transplantation

Recent data from the Swiss Transplant Cohort Study (STCS) investigated how recipient-donor sex mismatch affects clinical outcomes. Although sex differences are gaining attention in transplant medicine, the specific influence of recipient-donor sex combinations (RDSCs) on infections remained unclear. This retrospective study analyzed 5,033 adult recipients across various organs, including kidney, liver, heart, and lung, between 2008 and 2021.

Clinical Outcomes of Recipient-Donor Sex Mismatch

The results demonstrated that a recipient-donor sex mismatch does not independently increase the risk of posttransplant infections. For instance, researchers found no significant association with weighted infection risk across all four major organ groups. However, the study highlighted that biological sex itself plays a role. Female kidney recipients experienced significantly higher infection rates compared to their male counterparts. Specifically, the incidence rate ratio (IRR) for female kidney recipients was 1.50.

Furthermore, the study examined graft and overall survival. While sex combinations did not affect heart or kidney survival, they impacted liver transplants. Male liver recipients who received organs from female donors faced a higher risk of graft loss. Consequently, the data suggest that while infection risk is sex-independent regarding the donor, graft durability may still be influenced by RDSC in specific organs.

Key Takeaways for Transplant Specialists

Clinicians should note that while the donor's sex might not dictate infection protocols, recipient sex remains a crucial risk factor. Consequently, female kidney transplant recipients may require more vigilant monitoring for infectious complications. Moreover, the liver transplant data suggests that specific sex pairings might influence long-term graft durability. These findings emphasize the importance of personalized post-operative care plans in solid organ transplantation.

Frequently Asked Questions

Does the sex of the donor influence post-transplant infection rates?

No, the study found that recipient-donor sex mismatch was not significantly associated with posttransplant infection risk in heart, kidney, liver, or lung recipients.

Are female transplant recipients more prone to infections?

Yes, specifically in kidney transplantation, female recipients showed significantly higher infection rates (IRR: 1.50) compared to male recipients.

Which sex combination carries a higher risk for liver graft loss?

Male liver recipients who receive an organ from a female donor have a significantly higher risk of graft loss compared to other sex combinations.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice. Always seek the advice of a qualified healthcare provider with any questions regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Magyar CTJ et al. Recipient-Donor Sex Combinations and Posttransplant Infections: A Swiss Transplant Cohort Study. Transpl Infect Dis. 2026 May 26. doi: 10.1111/tid.70245. PMID: 42189585.

Shakeel S et al. Effect of Donor Sex on Graft Outcomes After Living Donor Kidney Transplant. Experimental and Clinical Transplantation. 2025; 5: 342-346.

Dummer JS. Infections After Solid Organ Transplantation. Medscape Reference. Updated March 2022.