The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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The mean pulmonary artery pressure (P(pa)) achieved on mild-to-moderate exercise is age related and its haemodynamic correlates remain to be documented in patients free of pulmonary hypertension (PH). Our retrospective study involved patients free of PH investigated in our centre for possible pulmonary vascular disease between January 1, 2007 and October 31, 2009 who underwent right heart catheterisation at rest and during supine exercise up to 60 W. The 38 out of 99 patients aged <50 yrs were included and a P(pa) of 30 mmHg was considered the upper limit of normal on exercise. ⋯ The eight patients with resting P(pa) 22-24 mmHg all had exercise P(pa) >30 mmHg. In subjects aged <50 yrs investigated for possible pulmonary vascular disease and free of PH, patients with mild-to-moderate exercise P(pa) >30 mmHg had higher resting PVRi and higher resting P(pa), although there was no resting P(pa) threshold value that could predict normal response on mild-to-moderate exercise. The clinical relevance of such findings deserves further long-term follow-up studies.
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A subset of asthma patients suffer from glucocorticoid (GC) insensitivity. T-helper cell type 17 cells have an emerging role in GC insensitivity, although the mechanisms are still poorly understood. We investigated whether interleukin (IL)-17A induces GC insensitivity in airway epithelium by studying its effects on responsiveness of tumour necrosis factor (TNF)-α-induced IL-8 production to budesonide in human bronchial epithelial 16HBE cells. ⋯ In contrast, IL-17A did not affect budesonide-induced transcriptional activity of the GC receptor, suggesting that IL-17A does not impair the actions of the ligated GC receptor. In conclusion, we have shown for the first time that IL-17A induces GC insensitivity in airway epithelium, which is probably mediated by PI3K activation and subsequent reduction of HDAC2 activity. Thus, blockade of IL-17A or downstream signalling molecule PI3K may offer new strategies for therapeutic intervention in GC-insensitive asthma.