Semilunar Valve Function After Rejection in Heart Transplant Recipients: Implications for Partial Heart...

Area of Science:

• Cardiology
• Immunology
• Transplantation Medicine

Background:

• Partial heart transplantation (PHT) is a developing procedure for pediatric semilunar valve disease.
• Current immunosuppression protocols for PHT mirror those for orthotopic heart transplant (OHT), but semilunar valve immune privilege is not well understood.
• Investigating rejection effects on semilunar valves in OHT can inform PHT immunosuppression strategies.

Purpose of the Study:

• To evaluate the impact of rejection episodes on semilunar valve function in pediatric orthotopic heart transplant (OHT) recipients.
• To determine if semilunar valves exhibit immune privilege, potentially altering immunosuppression needs for partial heart transplantation (PHT).

Main Methods:

• A retrospective case-control study of 113 pediatric OHT recipients (2008-2023).
• Patients were categorized by rejection presence/severity; semilunar valve function assessed via echocardiography.
• Subgroup analyses included rejection severity and age at transplant (<1 year).

Main Results:

• No significant differences in aortic/pulmonary valve gradients or regurgitation were found between rejection and non-rejection groups after a 3.8-year median follow-up.
• Paired analysis showed no change in valve function during rejection episodes compared to baseline.
• Similar outcomes were observed in infants transplanted before one year of age.

Conclusions:

• Pediatric OHT recipients' semilunar valve function remained unaffected by rejection over nearly 4 years, including high-grade cases and younger patients.
• Findings support semilunar valve immune privilege.
• Intensive immunosuppression may not be essential for preserving semilunar valve function in PHT.