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.