Aims/Purpose: Antibody-mediated rejection (ABMR) is the leading cause of long-term graft loss in pediatric kidney transplantation (KTx). While donor-specific HLA antibodies are well-established contributors to ABMR, emerging evidence suggests that non-HLA antibodies may also play a role in ABMR pathogenesis.
Methods: In this retrospective study, we assessed 60 different non-HLA antibodies in serum samples taken pre-, post-transplant and upon ABMR diagnosis from 77 pediatric KTx recipients to investigate their association with ABMR.
Results: During a median follow-up of 4.83 years, 29.8% of patients developed ABMR, with a median onset of 3.67 years post-transplant. The presence of non-HLA antibodies prior to KTx was not affected by pre-transplant dialysis, as 53 % of patients already exhibited over 15 positive non-HLA antibodies before KTx. The cumulative antibody profile remained stable 1–2 years post-KTx, with no association between late ABMR and cumulative strength or broadness of the non-HLA antibody profile.
Certain antibodies, including ACTIN, APOL2, COLLAGEN VI, HSPB1, thyroglobulin and TUBAP1, were more frequently observed in ABMR patients, although none demonstrated statistically significant predictive value.
Conclusion: This study suggests a potential role for non-HLA antibodies in pediatric ABMR. However, further large-scale studies are required to determine the prognostic relevance of specific non-HLA antibodies in pediatric renal transplant patients.