De novo human leukocyte antigen allosensitization patterns in patients bridged to heart transplantation using left ventricular assist devices.

INTRODUCTION: We examined the impact and time course of de novo human leukocyte antigen (HLA) allosensitization following left ventricular assist device (LVAD) implantation. METHODS AND RESULTS: Forty patients had a calculated panel reactive antibody (cPRA) prior to LVAD surgery between January 2014 and December 2018. Of these patients, we retrospectively studied 33 patients who had pre-LVAD cPRA <10%. De novo allosensitization was defined as cPRA ≥10% within 3 months following LVAD surgery, and "persistent allosensitization" was defined as cPRA ≥10% at time of heart transplant or death. One-third (11/33) of our cohort developed de novo allosensitization within 3-months post-LVAD. Median duration of follow-up during LVAD support was 588 days (IQR 337-1071 days), or approximately 19 months. In an adjusted, multivariable analysis, female sex remained associated with de novo allosensitization (adjusted odds ratio [95%CI]: 11 (1.4-85), P = 0.026). De novo allosensitization was subsequently associated with persistent allosensitization (P = 0.024). Both axial-flow and centrifugal-flow LVADs had similar rates of allosensitization. Compared to those with no allosensitization, patients with de novo allosensitization did not appear to have inferior post-transplant outcomes of death or treated rejection. CONCLUSION: In our single-center experience, one-third of patients developed de novo allosensitization which did not appear to associate with inferior post-transplant outcomes. Female sex was associated with de novo allosensitization.