Impact and predictors of positive response to desensitization in pediatric heart transplant candidates.
BACKGROUND
Desensitization, the process of reducing anti-human leukocyte antigen (HLA) antibodies in sensitized patients awaiting heart transplantation (HT), has unclear efficacy in pediatric HT candidates.


METHODS
Pediatric HT candidates listed at our institution between January 1, 2013 and June 30, 2018 were retrospectively evaluated. Sensitization was defined as the calculated panel reactive antibody (cPRA) ≥ 10% with ≥ 1 a strong positive antibody. The desensitization response was defined as a ≥ 25% reduction in the mean fluorescence intensity (MFI) for ≥ 90% of the strong positive antibodies on follow-up panel reactive antibody (PRA) testing before waitlist removal, HT, or death (data available for 13 patients).


RESULTS
The HT candidates were categorized as sensitized receiving desensitization therapy (ST, n = 14), sensitized not receiving therapy (SNT, n = 18), or non-sensitized (n = 55). A desensitization response was observed in 8 (62%) of the ST upon repeat PRA testing, with the ST responders receiving more doses of intravenous immunoglobulin (IVIG) (8 vs 2, p < 0.05). The anti-HLA class I antibodies were particularly resistant for non-responders (p = 1.9 × 10-4). The combination of homograft and ventricular assist device was more sensitizing than either alone (p = 3.1 × 10-4). However, these sensitization risk factors did not impact the desensitization response. The ST was associated with a higher likelihood of remaining listed and a longer waitlist time without substantially impacting the HT rate, waitlist mortality, or early post-HT outcomes.


CONCLUSIONS
Most ST patients had a favorable response to desensitization, with a dose-dependent response observed for IVIG. The anti-HLA class likely impacts the ST response, whereas traditional sensitization risk factors had no impact on the response.
['Edwards|Jonathan J|JJ|', 'Seliktar|Naomi|N|', 'White|Rachel|R|', 'Heron|Steven D|SD|', 'Lin|Kimberly|K|', 'Rossano|Joseph|J|', 'Monos|Dimitri|D|', 'Sesok-Pizzini|Deborah|D|', "O'Connor|Matthew J|MJ|"]
D002648:Child D002675:Child, Preschool D003888:Desensitization, Immunologic D005260:Female D016027:Heart Transplantation D006801:Humans D016756:Immunoglobulins, Intravenous D007223:Infant D008297:Male D012189:Retrospective Studies D014181:Transplantation Immunology D016896:Treatment Outcome
desensitization heart transplant intravenous immunoglobulin human leukocyte antigen sensitization pediatric transplant