Existence of circulating anti-endothelial cell antibodies after heart transplantation is associated with post-transplant acute allograft rejection.

Anti-endothelial cell antibodies (AECA) may be involved in the development of heart allograft rejection. Its detection might be a cheap and noninvasive method to identify high-risk patients. An indirect immunofluorescence method on human umbilical vein endothelial cells was used to investigate the presence of AECAs in 260 pre- and post-transplant serum samples sequentially collected from 34 patients within the first year after heart transplantation (HTX). The presence of AECAs before (23.5 %) and early after HTX (14.7 %) was associated with a significantly increased risk of early acute rejection (75 and 60 %, respectively) compared to 33 % in AECA-negative patients (p = 0.049). Moreover, rejections from AECA-positive patients were more severe (p = 0.057) with a significantly increased incidence of multiple (p = 0.025). The mean number of the sum of rejection episodes was significantly higher in AECA-positive patients (p ≤ 0.05). Patients free of AECAs mainly received mycophenolate mofetil as primary immunosuppression (p = 0.067). Nevertheless, the presence of AECAs did not affect long-term outcome and mortality of HTX patients. Despite a low number of patient samples, the detection of AECAs before and early after HTX could be used as a biomarker for an increased risk of early acute rejection in high-risk patients. This easy method might be a valuable tool to support screening procedures to improve individualized immunosuppressive therapy.