Inflammation, endothelial cell activation, and coronary microvascular dysfunction in women with chest pain and no obstructive coronary artery disease.

BACKGROUND: Coronary artery microvascular dysfunction is prevalent in women with chest pain in the absence of obstructive coronary artery disease (CAD) and is manifested by attenuated coronary flow reserve (CFR). Markers of inflammation and endothelial cell activation have been found to be elevated in patients with chest pain but without CAD. The relationship between inflammation, endothelial activation, and CFR is not known. METHODS: Ninety-four women with chest pain in the absence of obstructive angiographic CAD underwent catheterization-based assessment of CFR and measurement of levels of inflammatory markers (n = 78) and endothelial cell activation in the NHLBI WISE study. RESULTS: Coronary flow reserve did not correlate with levels of C-reactive protein (high-sensitivity C-reactive protein) (rs = -0.07, P = .53), interleukin (IL)-6 (rs = -0.12, P = .31), IL-18 (rs = 0.14, P = .23), tumor necrosis factor alpha (rs = -0.09, P = .43), transforming growth factor beta1 (rs = 0.02, P = .84), and soluble intracellular adhesion molecule-1 (rs = 0.04, P = .68). Median levels of markers of inflammation and endothelial cell activation did not differ between the 57 women with abnormal CFR (< 2.5) and the 37 women with normal coronary microvascular function (high-sensitivity C-reactive protein 0.32 vs 0.25 mg/dL, P = .80; IL-6 2.89 vs 2.39 pg/mL, P = .63; IL-18 218 vs 227 pg/mL, P = .59; tumor necrosis factor alpha 2.7 vs 2.4 pg/mL, P = .43; transforming growth factor beta1 9928 vs 12436 pg/mL, P = .76; soluble intracellular adhesion molecule-1 286 vs 287 pg/mL, P = .95). Multivariable models demonstrated no evidence of associations between markers of inflammation and of endothelial cell activation and CFR. CONCLUSIONS: Coronary microvascular dysfunction is not associated with markers of inflammation and endothelial cell activation in women with chest pain in the absence of obstructive CAD. These results suggest that inflammation and endothelial cell activation may not play a pathophysiological role in coronary microvascular dysfunction.

A novel epitope of N-CAM defines precursors of human adherent NK cells.

Activated, adherent natural killer (A-NK) cells represent a distinct subpopulation of interleukin (IL)-2-stimulated NK cells, which are selectively endowed with the increased expression of integrins and ability to adhere to solid surfaces, migrate into, infiltrate, and destroy cancerous tissues. The present study defines the phenotype and functions of precursors of A-NK (pre-A-NK) cells in humans. Peripheral blood pre-A-NK cells, in contrast to the rest of NK cells, express a novel epitope of CD56 neuronal cell adhesion molecule, termed ANK-1, and increased cell-surface levels of integrins. Pre-A-NK cells also express low levels of CD56 and CD161, and some express CD162 receptor, do not express CD25 or activation markers, and are effective mediators of NK cytotoxicity. Thus, pre-A-NK cells are generally similar to CD56(dim) NK cells. However, pre-A-NK cells differ from the main NK cell subpopulation by having a lower expression level of CD16 and a lower ability to mediate redirected antibody-dependent, cell-mediated cytotoxicity. More importantly, pre-A-NK cells are preferentially endowed with the ability to rapidly respond to IL-2 by integrin-mediated adherence to endothelial cells, extracellular matrix, and plastic. This early, specific response of pre-A-NK cells to IL-2 is followed by their activation, vigorous proliferation, and differentiation into phenotypically and functionally similar A-NK cells. Pre-A-NK cells represent only approximately 26% of peripheral blood NK cells but encompass the majority of NK cells in normal and cancerous, solid tissues. We conclude that pre-A-NK cells represent a distinct subset of resting, mature NK cells with the characteristics indicative of their ability to migrate and reside in solid tissues.