Allosensitization in Children Supported with Ventricular Assist Devices

Purpose The presence of Human Leukocyte Antigen (HLA) antibodies (Ab) can be a risk for rejection/graft loss in heart transplant (HTx) patients (pts). Our aim was to study immunologic profiles and outcomes of long-term pediatric VAD pts compared to non-VAD pts. Methods and Materials Retrospective study of pts bridged to transplant (BTT) on long term VAD support (>30 days) between 1999-2012, compared to non-VAD pts requiring transplant. PRAs were performed on sera collected pre and post-VAD and serially until HTx for VAD pts, and prior to listing and serially until HTx for non-VAD pts. Mortality and rejection (ISHLT grade >2R) events were recorded. Results 34 pts were placed on a VAD compared to 50 age/gender matched non-VAD controls. 2 pts died, 1 pt recovered, 1 still supported. The average age was 7.5 years (0.2 – 21.7). 50% of pts pre-VAD had positive HLA class I Ab (19±12%) or HLA class II Ab (23±11 %) but post-VAD, were non-reactive with 0% HLA class I and class II Ab. This was comparable to the pre-Tx HLA Ab profile of 54% (27/50) of the non-VAD pts. In contrast, 50% of the VAD pts presented both pre-VAD with HLA class I (31±22 %) and class II Ab (44±34%) and post-VAD with class I (36±25%) and class II (41±31%) HLA Ab. Comparatively, 46% (23/50) of non-VAD pts were also HLA class I and class II Ab positive pre and post-HTx. There was no difference in VAD vs non-VAD post-HTx survival (log rank=0.494, figure 1 ). There were more rejection episodes in non-VAD pts compared to VAD pts (95% vs 50%, p Conclusions HLA profiles were comparable between VAD pts and non-VAD pts. VAD placement did not affect HLA sensitization after implant. There were more rejection episodes in non-VAD pts and long-term survival post-HTx was unaffected between groups.