Disease complexity in acute coronary syndrome is related to the patient's immunological status

Our aim was to investigate whether patients with acute coronary syndrome (ACS) display an overall T cell immunosenescence that could be contributing to worsening the stage of the disease.

We compared the immunological status of 52 ACS patients, 21 controls with absence of coronary artery disease (CAD) (C1), and 50 healthy individuals (C2). We characterized leukocyte and T lymphocyte subpopulations by flow cytometry. CAD was classified according to SYNTAX score, number of diseased coronary vessels, previous episodes of ACS and left ventricular ejection fraction (LVEF). ACS patients showed an increased number of total leukocytes, neutrophils and monocytes (p < 0.001), but a decreased number of lymphocytes (p < 0.05). ACS patients had significantly higher levels of NK cells and CD8+ T-cells (p < 0.05). ACS was associated with high differentiation in CD4+ and CD8+ T-lymphocytes. Frequencies of naïve, naïve CD31+, EM1, and pE1 subsets were significantly reduced in ACS patients (p < 0.05), while EM3, EM4 (in CD4+), and E (in CD8+) subsets were increased (p < 0.05). Aging of T-lymphocyte subpopulations was associated with a worse SYNTAX score (p < 0.05), and aging of CD4+ T-lymphocytes with a larger number of affected vessels, larger number of previous ACS episodes and lower LVEF, in ACS patients (p > 0.05). Furthermore, the proliferation ability of CD4+ and CD8+ T-lymphocytes was significantly impaired in ACS patients (p < 0.05), although they had increased activation (p < 0.05).

We conclude that ACS patients show a higher degree of T-lymphocyte immunosenescence than healthy controls, which could contribute to disease impairment through a compromised adaptive immune response.