Atopy is characterized by an immune system that is biased to T helper cell, type 2 (Th2) activation. This condition predisposes to asthma, a disease in which a Th2 activation was found in blood and lungs. However, most blood studies have considered purified cells, which might give an incomplete view of immune reactions. In this study, we assessed in whole blood cultures the Th1/Th2 paradigm in atopy and asthma. Sixty-nine subjects (31 atopic asthmatics, six nonatopic asthmatics, 13 atopic nonasthmatics, and 19 control subjects) were included in this study. Interleukin-4 (IL-4), interferon gamma (IFN-gamma), and IL-12 were assayed in stimulated whole blood culture supernatants by using a flow cytometer microsphere-based assay. Intracellular IL-4 and IFN-gamma were detected in T cells and CD8(+) T cells by flow cytometry. Atopy was characterized by a higher production of IL-4, which was correlated to total IgE levels, and by an impairment of the T-cell capacity to produce IFN-gamma. This impairment was correlated to the number of positive skin tests. In asthma, the overproduction of IL-4 was still found if atopy was present. Unexpectedly, an overproduction of IFN-gamma was found, which was related to an increased capacity of CD8(+) T cells to produce IFN-gamma. The number of IFN-gamma-producing CD8(+) T cells was related to asthma severity, to bronchial hyperresponsiveness, and to blood eosinophilia. In addition, this number was correlated to IL-12 production. These results show that in addition to the well-known Th2 inflammation in asthma, there are IFN-gamma-producing CD8(+) T cells in the blood, possibly controlled by IL-12.
Abnormal left ventricular (LV) diastolic function has frequently been reported in patients with chronic obstructive pulmonary disease (COPD). In the present work, diastolic function was studied by a combined analysis of pulmonary venous and mitral blood flow velocities in 34 patients with COPD clinically stable and without history of heart disease, and 20 control subjects. We confirmed the increased contribution of the atrial contraction to the LV filling in COPD patients in comparison with control subjects; furthermore, a decreased left atrial (LA) filling during the ventricular systole was observed. Changes in LV filling were not the consequence of a systolic dysfunction, because LV systolic function was normal. Doppler indices indicated that LA pressure was below 15 cm H(2)O in all the patients with COPD and control subjects. Several factors can be put forward to explain these changes; the first one is tachycardia. In addition to hypoxemia and medications, echocardiography suggested that a decreased LV preload participated in increased heart rate. Analysis of Doppler transmitral and pulmonary venous flows demonstrated the role of the ventricular interdependence because a correlation existed between LA and LV filling pattern and right ventricle pressure and diameter.
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