Comprehensive Characterization of Anti-HLA and Non-HLA Antibodies in Patients on Kidney Transplant Waiting List and Evaluation of Their Impact on Alloimmunization Risk and Dialysis Treatment

Alloimmunization remains a major obstacle to successful kidney transplantation, mainly due to the formation of anti-HLA antibodies. In recent years, non-HLA antibodies have emerged as additional immunologic factors that can potentially contribute to graft rejection. The aim of this study was to investigate the prevalence and specificity of both anti-HLA and non-HLA antibodies in patients with end-stage renal disease on a waiting list for kidney transplantation. Serum samples from 74 patients were analyzed using complement-dependent cytotoxicity and solid-phase assays. IgG anti-HLA antibodies were identified in 43.2% of participants, while IgG non-HLA antibodies were detected in 91.9%. The most frequent non-HLA antibodies included anti-ENO1 (28.4%), anti-FIBR1 (23.0%) and anti-PRKCZ (23.0%). A significant difference was found between the number of distinct IgG anti-HLA and IgG non-HLA antibody specificities. However, no significant correlation was found between the number of IgG non-HLA antibody specificities and previous alloimmunization events or dialysis treatments. These results suggest that non-HLA antibodies, although often overlooked, can sometimes play a critical role in transplant outcomes. Routine testing for non-HLA antibodies, in addition to mandatory anti-HLA antibody screening and identification, could improve immunologic risk assessment in transplant patients and post-transplant care.