Introduction:
Vascular endothelium, which expresses antigens, could be targeted by various antibodies, and it is the first barrier between the immune system and the allograft in kidney transplant recipients (KTRs). We aimed to outline the clinical significance of anti-endothelial cell antibodies (AECA) in paediatric KTRs.

Material and methods:
Serum AECA IgG titres were measured pre and post renal transplantation in 46 paediatric kidney transplant recipients and in 12 age- and gender-matched healthy controls by ELISA technique.

Results:
In KTRs, AECA titres were significantly increased after transplantation compared to both pre-transplantation (1.66 ±0.90 vs. 0.76 ±0.58 ng/ml, p = 0.002) and healthy controls (1.66 ±0.90 vs. 0.6 ±0.2 ng/ml, p = 0.004). In KTRs, AECA titres were significantly increased in living unrelated compared to living related renal grafts (3.3 ±3.9 vs. 1.09 ±0.87 ng/ml, p = 0.003) and were significantly affected by the type of induction therapy (in anti-thymocyte globulin, n = 30), basiliximab (n = 9) and no antibody induction (n = 7) groups; (1.32 ±1.18, 2.5 ±4.37 and 2.01 ±2.27 ng/ml respectively, p = 0.0372). Anti-endothelial cell antibodies titre was detected positive (≥ 1.2 ng/ml) in 21% (3 patients) of KTRs with acute rejection (AR) (n = 14) and in 28% (2 patients) of KTRs with chronic graft dysfunction (n = 7).

Conclusions:
In KTRs, AECA titre is increased after kidney transplantation without a significant correlation with AR. Anti-endothelial cell antibodies titre is influenced by donor relations and antibody induction.