IL-6 secretion. Alteration in blood circulating concentrations of IL-6 was measured by ELISA. Heparinized blood sample of donor or recipient was collected before (day-35) and at various time after (day + 4, 7, 30, 90, 180) the MSC-kidney transplantation. Plasma was separated and stored at −70°C until the ELISA was performed using commercial kit from OptEIA™ (e-bioscience, San Jose, CA, USA). Asterisks indicate the statistical significance of cytokine secretion compared to D-35 baseline activity (p < 0.05).