Characterization of T-cells and NK-cells phenotype in peripheral blood of patients with aortic valve disease and thoracic aortic aneurysm

Objective: Histopathological investigations demonstrated an important role of the leukocyte infiltration in the evolution of the aortic valve disease (AVD) and thoracic aortic aneurysm (TAA). The aim of our study is to investigate the eventual association between a distinctive T-cells and NK-cells phenotype in peripheral blood and the development of aortic degenerative diseases. Methods: Blood samples obtained from 10 TAA (66.20±5.71 y.o., 6 males) and 10 AVD (69.80±4.59 y.o., 4 males) patients. A flow cytometric analysis performed by appropriate combinations of monoclonal antibodies directed against the following surface molecules: CD3, CD4, CD28, CD8, CD56, CD16, TCRgamma/delta, TCR Vbeta11/Valfa24 (iNKT), CCR5, CXCR3, CX3CR1. Results: In TAA group we observed a higher fraction of circulating NK cells (11.727±1.33 vs. 8.063±1.36, P=0.074), together with a higher fraction of NK cells positive for the chemokine receptor CX3CR1 (87.769±1.92 vs. 79.356±3.22, P=0.039) in comparison to AVD group. The CD8+ T-cell subset exhibited a higher positivity for CCR5 expression in TAA group (21.296±2.37 vs. 16.259±1.24, P=0.078). A higher RFI for CX3CR1 was observed on gamma/delta+ T-cells in TAA group (258.111±12.19 vs. 221.556±13.61, P=0.062). On total CD4+ T-cells a higher percentage of positivity for CCR5 has been observed (16.131±1.21 vs. 13.029±0.90, P=0.057). An augmented CD25 expression on the cytotoxic CD28-/CD4+ T-cells was found in TAA group (22.233±8.11 vs. 9.087±1.60, P=0.131). Conclusions: Increase in number of NK and iNKT, chemokine receptor expression on NK, CD8+ and gamma/delta+ subsets and CD25 expression on CD28-/CD4+ T-cells, suggest a higher cytotoxic potential in peripheral blood of TAA patients.