NT-proBNP and the anti-inflammatory cytokines are correlated with endothelial progenitor cells' response to cardiac surgery

Objective: We used cardiac surgery as a model of acute inflammatory response to evaluate the role of the inflammatory mediators in influencing the number of circulating endothelial progenitor cells (EPCs). Methods: In 38 coronary artery by-pass grafting (CABG) [28M/10F] and in 54 valvular [28M/26F] patients the numbers of EPCs and the serum levels of IL-1ra, IL-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), high sensitivity C-reactive protein (hsCRP) and NT-proBNP were determined before (T1), 72 h (T2), and 10 days after cardiac intervention (T3). Peripheral blood EPCs were measured by flow cytometric analysis and were defined as CD34+KDR+, CD133+KDR+ and CD34+CD133+KDR+. Results: We demonstrate that the cardiac surgery reduces, 72 h after intervention, the number of all the three types of EPCs with a contemporary marked increase of pro-inflammatory and anti-inflammatory cytokines and NT-proBNP levels. At baseline, EPC number was inversely related with age. At multiple linear regression analysis, after adjusting for age, cardiovascular risk factors and medications, age and IL-8 serum levels were significantly related to EPC number. At T2, an inverse relationship between NT-proBNP and the number of EPCs was found in the whole study population. At T3, 10 days after the intervention, at multivariate linear regression analysis, IL-10 and IL-1ra serum levels were significantly and positively associated with EPC number. Conclusions: This study provides new insights into the relationship between inflammatory activation and mobilisation of EPCs in patients underwent cardiac surgery, by showing that NT-ProBNP and cytochemokines mediate the EPC changes in acute and post-acute response to the inflammatory stimulus of intervention.