HLA Sensitization within One-Year of VAD Implantation: Prospective Study in Adults and Pediatrics

Abstract

<h3>Purpose</h3> Ventricular assist devices (VADs) have improved survival to heart transplant (HTx). However, VADs have been associated with the development of human leukocyte antigen antibodies (HLA-Ab) which may limit the donor pool and increase risk for worse outcomes post-HTx. Since HLA-Ab development after VAD insertion is poorly understood, the aim of this prospective study was to quantify the incidence of and risk factors for HLA-Ab development post-VAD insertion across the age spectrum. <h3>Methods</h3> Adult and pediatric patients who were undergoing durable VAD placement between 5/2016 and 7/2020 were enrolled. HLA-Ab were assessed pre-VAD and at approximately 1, 3, and 12 months post-implant. HLA-Ab were measured by Luminex screen; all positive/borderline screens were confirmed by Luminex single antigen beads. Factors associated with HLA-Ab development post-VAD implant were explored. <h3>Results</h3> The study cohort included 41 adult and 17 pediatric patients. Following implant, 37% of adults and 41% of pediatric patients developed new HLA-Ab. The majority of patients (19/22) developed HLA-Ab within two months of implant and three patients developed HLA-Ab within four months post-implant. Of those that developed HLA-Ab, class I antibody development was most common (80% adult and 86% pediatric patients). Factors associated with HLA-Ab development within one year are listed in Table 1. <h3>Conclusion</h3> More than one-third of adult and pediatric VAD patients developed new HLA-Ab early after implant with the majority specific to class I. HLA-Ab development in adults was associated with female sex and pre-VAD HLA sensitization; these associations were not identified in pediatric patients. Further studies into the persistence of HLA-Ab over time in VAD patients and the clinical impact of HLA-Ab on long-term outcomes are needed.