Lymphocyte subpopulations in myocardial infarction: a comparison between peripheral and intracoronary blood

The frequency and profile of lymphocyte subsets within the culprit coronary artery were investigated in 33 patients with myocardial infarction and compared to their systemic circulating counterparts. T cell subsets including CD4(+)CD28null, activated and regulatory T-cells, TH1/TH2/TH17 phenotypes, NK and B-cells were studied in intracoronary (IC) and arterial peripheral blood (PB) samples. CD4(+)CD28null T-lymphocytes were significantly increased in IC compared to PB (3.7 vs. 2.9 %, p < 0.0001). Moreover, patients with more than 6 h of evolution of STEMI exhibited higher levels of CD4(+)CD28null T-cells suggesting that this subset may be associated with more intense myocardial damage. The rare NK subpopulation CD3(-)CD16(+)CD56(-) was also increased in IC samples (5.6 vs. 3.9 %, p = 0.006). CD4(+)CD28null T-cells and CD3(-)CD16(+)CD56(-) NK subpopulations were also associated with higher CK levels. Additionally, IFN-γ and IL10 were significantly higher in IC CD4(+) lymphocytes. Particular immune cell populations with a pro-inflammatory profile at the site of onset were increased relative to their circulating counterparts suggesting a pathophysiological role of these cells in plaque instability, thrombi and myocardial damage.