(397) - Donor-Specific HLA Alloantibodies: Impact on Cardiac Allograft Vacsulopathy and Survival After Pediatric Heart Transplantation

Abstract

There is increasing evidence that the de novo donor-specific anti-HLA antibodies (DSA) are associated with poor outcome following solid organ transplantation. However, little data is available in pediatric heart transplant (HTx) recipients. The objective of this study is to determine the impact of de novo DSA on the development of cardiac allograft vasculopathy (CAV) and survival in a cohort of pediatric HTx recipients. Retrospective review of the medical records of the 105 pediatric patients (age <18 years) between 2002 and 2012 who received HTx at our center. All patients included in the study had negative post-transplant T-cell and B-cell cross match. Patients were screened for HLA antibodies at 1, 2, 3, 6, 12 months, annually and whenever there was clinical suspicion for rejection. The antigen specificity of the detected HLA class I and class II antibodies was identified using a Luminex assay. The strength of DSA with MFI >5000 was considered strong and used for this study as +ve DSA. Kaplan-Meier method was used to estimate allograft survival. The cumulative frequency of DSA was 39/105 patients (37%). The majority of detected DSA were donor specific for HLA class II. Mean follow-up was 3.5±2.7, range 0.9 to 10 years. Development of CAV occurred in 16/39 (41%) in DSA +ve compared to 8/66 (12%) in DSA -ve patients. Allograft survival at 5 years was 24% in DSA +ve compared with 76% in DSA -ve cases (p< 0.001) (Figure). Our results demonstrate a strong negative impact of development of de novo DSA on CAV and allograft survival in pediatric HTx recipients.