Sex-Based Differences in Rejection Among Pediatric Solid Organ Transplant Recipients.

Background: Immunosuppression is paramount to prevent acute rejection in solid organ transplant but also poses a risk for infection and malignancy. Identifying factors that influence rejection may allow for personalization of treatment and avoidance of an unnecessary degree of immunosuppression for the vulnerable pediatric population.

Methods: We conducted a retrospective review analyzing public data provided by the Organ Procurement and Transplantation Network for pediatric patients listed for solid organ transplantation (kidney, liver, lung, and heart) from March 1998 to December 2022. Univariate and multivariate logistic regression was used to identify independent risk factors for treated acute rejection at 6 months and/or 1 year for liver, lung, kidney, and heart transplants.

Results: The study population consisted of the following pediatric patients for each organ studied: liver (n = 8993), lung (n = 846), heart (n = 7118), and kidney (n = 14 600). At 1 year, 28.4% and 31.7% of males and females, respectively, were treated for rejection in liver transplant, 24.1% and 34.5%, respectively, for lung, 14.8% and 16.2%, respectively, for kidney, and 25.2% for both in heart transplant. In multivariate analysis, male recipient status was a statistically significant protective factor against rejection in liver transplant, OR = 0.85 (p < 0.001), lung transplant, OR = 0.61 (p = 0.004), and kidney transplant, OR = 0.91 (p = 0.040), but not heart transplant, OR = 0.96 (p = 0.460).

Conclusions: Our study demonstrates that pediatric males may have a lower risk of acute rejection in liver, lung, and kidney transplant yet not in heart transplant. These findings may have implications for the level of maintenance immunosuppression for pediatric male transplant recipients.