P007 Transfusion-induced HLA antibodies are transient and do not rebound following heart transplantation

Abstract

Aim To determine the impact of blood transfusions (BTf) given at the time of ventricular assist device (VAD) implantation on HLA antibody (Ab) production, and the clinical relevance of BTf-induced HLA Abs in heart transplantation (HTx). Methods This study includes 54 patients that received a VAD implant between 03/2012 and 05/2016. The amount and type of BTf given during VAD procedure were obtained from patient charts. Multiple sera collected during pre-VAD, post-VAD, and post-HTx periods were analyzed for HLA Abs using One Lambda single antigen beads. Results Of the 54 VAD-implanted patients, 19 (35%) showed a significant increase in HLA Ab specificities and/or strength in post-VAD samples compared to pre-VAD samples; 26 (48%) did not show any significant change in HLA Ab profile; 9 (17%) remind negative for all HLA Abs. Patients who showed significant changes in HLA Abs received more BTf (across all blood components) compared to those displayed little/no change in HLA Abs.BTf-induced HLA Abs are transient and disappear in 5–6 months, while pregnancy-induced HLA Abs are persistent (see figure). Majority of these VAD patients ( n = 37; 69%) received HTx, and 29 HTx recipients had no detectable donor-specific HLA antibodies (DSA) in pre- and post-VAD sera, and remained to be DSA negative following HTx. Three recipients had no DSA in pre-VAD samples, but developed DSA in post-VAD samples, then completely negative following HTx; 5 recipients had DSAs (∼2000 MFI) in both pre- and post-VAD samples, and persistent in post-HTx sera with similar MFIs. The average wait time for a HTx differs among the 3 groups: patients with no HLA Abs waited for ∼5 months, patients with little/no change waited for ∼9 months, and those showed significant change waited for a year. Conclusions HLA Ab production after VAD implantation is common and correlates with amount of BTf a patient receives. This sensitization does not affect HTx as well as post-tx DSA development. Therefore, the BTf-induced HLA Abs appear to be transient and clinically irrelevant in HTx. Download high-res image (446KB) Download full-size image