Usefulness of impulse oscillometry in patients with asymptomatic bronchial asthma / 천식및알레르기

BACKGROUND: Impulse oscillometry (IOS) is a valuable method for evaluating respiratory func- tion in a patient with bronchial asthma. There have been no reports on compliance assessment of the remodeled airway by estimation of the relationship between resistance and breathing volume in asymptomatic asthma using IOS. OBJECTIVE: This study was performed to evaluate whether IOS could distinguish asymptomatic asthma from healthy control and detect altered physiology of the airway due to airway remodeling in asymptomatic asthmatic patients with normal pulmonary function. METHOD: 16 healthy and 16 asymptomatic patients with bronchial asthma were asked to breathe with the usual tidal volume (Vt) and with twice the amount of Vt. Using IOS, impedance, resistance for frequency at 5Hz and 20 Hz, reactance, and resonant frequency were measured. RESULTS: Resonant frequency was significantly higher in asymptomatic asthma than in healthy control for breathing with both usual Vt and twice the amount of Vt (mean+/-S.E.M. 16.35+/-1.44 Hz vs 13.34+/-0.66 Hz, 16.27+/-0.72 Hz vs 13.68+/-0.66 Hz, p<0.05 respectively), but the discriminant power of resonant frequency for distinguishing asymptomatic asthma from healthy control was low. There were no significant differences of other IOS parameters between asthma and control groups. Compared with control group, asymptomatic asthma group showed no significant change of IOS parameters according to breathing volume change. CONCLUSION: In this study, we could not find any IOS parameters sensitive enough to detect altered physiology of the remodeled airway in patients with asymptomatic bronchial asthma. Further studies are recommended to improve sensitivity of IOS method for investigating airway physiology in bronchial asthma.

Circulating Levels of Interleukin-6 and Soluble Interleukin-6 Receptor in Acute Asthma / 결핵

BACKGROUND: The recognition of bronchial asthma as an inflammatory disease led to a search for soluble markers that would be useful in assessing airway inflammation. Interleukin-6 (IL-6) is a representative proinflammatory cytokine that has been shown to be connected with various inflammatory diseases. IL-6 acts via specific receptors that consist of the IL-6 binding glycoprotein gp80 and the signal transducer gp130. In the search for markers of airway inflammation, we investigated the role of soluble interleukin-6 receptor (sIL-6R) and IL-6 in acute asthma. METHODS: Serum levels of sIL-6R and IL-6 were measured in 78 acute asthmatics, in 15 patients with asymptomatic asthma and in 10 healthy control subjects by a specific ELISA using a murine antihuman IL-6R, IL-6 mAb (Quantikine sIL-6R, IL-6). RESULTS: Serum levels of IL-6 in acute asthmatics significantly exeeded those of control subjects. Those of sIL-6R in acute asthmatics were also significantly increased compared to those of control subjects. The serum concentration of IL-6 obtained in acute asthmatics was elevated as compared with the asymptomatic asthmatics. However, Association between eosinophilic count / IgE and IL-6 / sIL-6R in acute asthma could not found. CONCLUSION: Our results suggest that IL-6 may be involved in the pathogenesis of acute asthma and serum levels of IL-6 and sIL-6R may reflect the severity of airway inflammation.