Abstract
BACKGROUND: Increasing cough reflex sensitivity associated with neurogenic inflammation of airway is thought to have a major role in the pathogenesis of Post-infectious cough. TRPA1 is activated by various proinflammatory neuropeptides at the peripheral terminals and exogenous pollutant molecules relevant to respiratory diseases.
METHODS: 35 healthy volunteers(Group A) and 25 patients of Post-infectious cough(Group B) recruited via public postings and outpatient services of our hospital were challenged with doubling concentrations of cinnamaldehyde(50, 100, 200, 400, 800mM) by a breath-activated dosimeter until the concentration inducing five or more coughs was reached. The thresholds of cough reflex were defined as the lowest concentrations of cinnamaldehyde that elicted two or more coughs (lg C2) and five or more coughs (lg C5), respectively.
RESULT: During the process of test, there was no serious side effect in all subjects, but one has a sense of nausea. The variation of General lung ventilation including FEV1{[3.35±0.53,3.35±0.52],[2.76±0.82,2.71±0.73]}, FVC{[3.72±0.70,3.71±0.71],[3.30±0.78, 3.29±0.76]}and FEV1/FVC {[ 90.6±5.42, 90.9±4.92],[ 83.6±4.45, 82.4+5.04]}, showed no significant differences(P<0.05). There were no significant differences in cough reflex sensitivity represented by the lg C2 (2.48±0.43mM)and the lg C5 (2.59±0.39mM) between Group A and Group B, but both C2 and C5 of female subjects were significant higher in two groups.
CONCLUSION: Cinnamaldehyde challenge has established to be a effectively objective method for evaluating airway hypersensitivity with high reproducibility.
- © 2014 ERS
