Association of Donor-Specific Antibodies with Rejection and Graft Outcomes in Pediatric Kidney Transplant Recipients:...

De novo donor -specific antibodies are recognized mediators of alloimmune injury after kidney transplant, yet their clinical significance in pediatric recipients remains incompletely defined. We evaluated the incidence of de novo donor -specific antibodies and the associated rejection patterns and graft outcomes in a pediatric kidney transplant cohort.

This retrospective single -center study included pediatric kidney transplant recipients who underwent transplants between 2009 and June 2024. Donor -specific antibody positivity was determined using Luminex -based assays (mean fluorescence intensity >1000 ). Clinical, immunologic, and functional outcomes were compared between patients positive for donor -specific antibodies and patients negative for donor -specific antibodies, including rejection phenotype, estimated glomerular filtration rate, graft loss, and duration of follow -up.

Among 78 recipients, 15 recipients (19.2 % ) developed de novo donor -specific antibodies during a mean follow -up of approximately 4 years. Acute rejection occurred more frequently in patients positive for donor -specific antibodies versus patients negative for donor -specific antibodies (80 % vs 32 %, respectively; P = .053 ), predominantly antibody -mediated or mixed phenotypes. Graft loss rates were comparable between groups (13.3 % vs 14.2 %; P = 1.000 ). Although not statistically significant, recipients positive for donor -specific antibodies demonstrated numerically lower eGFR values at 1 year and at last follow -up (49.6 ± 22.2 vs 57.1 ± 29.8 mL /min /1.73 m ² at last visit, respectively; P - .445 ).

In this pediatric cohort, de novo development of donor -specific antibodies was associated with a higher tendency toward antibody -mediated rejection, without a significant difference in short -term to mid -term graft survival. Continued surveillance of donor -specific antibodies and longer follow -up are warranted to clarify the long -term clinical effect of donor -specific antibodies in pediatric kidney transplants.