Plasma levels of interleukin 2, 6, 10 and phenotypic characterization of circulating T lymphocytes in ischemic heart disease

The purpose of this study was to assess lymphocyte receptors expression in patients with ischemic heart diseases, as well as to measure the plasma lev els of interleukin (IL) 2, 6 and 10. T Lymphocytes are found in large numbe rs in human atherosclerotic plaques, indicating that immune and inflammator y mechanisms are important factors in the pathogenesis of atherosclerosis. Recent data have also implicated T lymphocytes in the pathogenetic mechanis m of unstable angina and ischemic heart disease. Three groups of patients w ere studied: 42 with an acute ischemic syndrome (AIS), 36 with stable angin a (SA) and 39 healthy controls. To characterize lymphocyte phenotype, flow cytometry was performed in whole-blood samples. IL-2, IL-6 and IL-10 were m easured using the ELISA method. Double fluorescence evaluation showed an in crease in CD8 + /CD11b + cells (cytotoxic T lymphocytes) and in CD11b + /CD 16 + CD56 + cells (NK lymphocytes) in the AIS group and in SA group as comp ared to the control group (P < 0.05 and P < 0.001, respectively). IL-2 was increased in the AIS and SA groups compared to the control group (AIS 4.5 /- 0.5 pg/ml; SA 6.3 +/- 0.6 pg/ml; controls 2.4 +/- 0.8 pg/ml, P < 0.05), whereas IL-6 was higher in the AIS group than in the other two groups (AIS 10.8 +/- 1.8 pg/ml; SA 1.8 +/- 0.8 pg/ml; controls 1.2 +/- 0.6 pg/ml, P < 0 .0001). These data show that patients with ischemic heart disease have an i ncrease in circulating cytotoxic T lymphocytes and in IL-2 plasma levels, i rrespective of their clinical presentation, compared to normal control subj ects, whereas IL-6 is elevated only in patients with AIS. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.