RESUMO
<p><b>OBJECTIVE</b>To observe the T helper 1 and T helper 2 (Th1/Th2) balance and possible association to vascular endothelial cells injury in patients with acute coronary syndromes (ACS).</p><p><b>METHODS</b>Forty patients with ACS and 18 patients with stable angina pectoris (SAP) were included in this study. The concentrations of T helper 1/T helper 2 subsets related cytokines in plasma were evaluated by ELISA Kits. Cytotoxic activity of peripheral blood mononuclear cells (PBMCs) or PBMCs depleted CD(+) T cells against human umbilical vein endothelial cells (HUVECs) were evaluated by Cr51 cytotoxicity assay.</p><p><b>RESULTS</b>Concentrations of T helper 1 related cytokines IFN-gamma and IL-2 were significantly higher [IFN-gamma: (131.2 +/- 42.2) ng/L vs. (47.6 +/- 20.2) ng/L; IL-2: (83.7 +/- 21.3) ng/L vs. (46.2 +/- 16.7) ng/L, all P < 0.05] while T helper 2 related cytokine IL-10 concentration was significantly lower [(16.7 +/- 4.3) ng/L vs. (27.5 +/- 5.5) ng/L, P < 0.05] in patients with ACS compared to those in SAP patients. Cytotoxic activity of PBMCs against HUVECs in patients with ACS was also significantly higher than that in patients with SAP (28.84% +/- 4.20% vs. 20.28% +/- 2.71%, P < 0.05).</p><p><b>CONCLUSIONS</b>In patients with ACS, Th1 related cytokines were significantly upregulated while Th2 related cytokines were significantly downregulated. This imbalance of Th1/Th2 accelerated PBMCs mediated endothelium injury in patients with ACS.</p>