Concomitant endothelin-1 overexpression in lung transplant donors and recipients predicts primary graft dysfunction

Primary graft dysfunction (PGD) causes significant morbidity following lung transplantation (LTX). Mortality is high in PGD and therapeutic strategies are limited. To investigate whether endothelin-1 (ET-1) that mediates increased vascular permeability and edema formation in lung grafts can predict PGD, ET-1 mRNA expression was examined in lung tissue biopsies of 105 donors and recipients obtained shortly before LTX. Serum ET-1 concentration was assessed by ELISA. PGD grade was diagnosed and scored by oxygenation and radiological characteristics according to ISHLT guidelines. PGD grade 3 developed in 11% of patients. ET-1 mRNA expression was significantly increased in both donor (p < 0.0001) and recipient (p = 0.01) developing PGD as compared to no PGD group. Pretransplant ET-1 serum concentrations were elevated in recipients with PGD as compared to no PGD group (p < 0.0001), although serum ET-1 was not different between donors whose grafts developed PGD grades 0-3. In regression analysis, concomitant elevated donor tissue ET-1 and recipient serum ET-1 predicted PGD grade 3. This study indicates that pretransplant ET-1 mRNA overexpression in donors associated with elevated pretransplant serum ET-1 in recipients contribute to PGD development and that their assessment might be beneficial to predict PGD and to identify recipients who could benefit from a targeted ET-1 blockade.