A Study on the Mechanism of Cough Hypersensitivity
A Study on the Mechanism of Cough Hypersensitivity
The aim of this study is described as follows,

 1. To establish a validated method to test cough reflex sensitivity conducted by transient
 receptor potential vanilloid 1(TRPV1).

 2. To observe the variance of cough reflex sensitivity conducted by transient receptor
 potential ankyrin 1(TRPA1) of chronic patients and the relationship between cough reflex
 sensitivity conducted by TRPA1 and conducted by TRPV1.

 3. To study the distribution of TRPA1 and TRPV1 channels and their relationship to cough
 reflex sensitivity.
This study is divided into two major part, Firstly,to observe the variance of cough reflex
 sensitivity of chronic cough patients and the relationship between it and airway
 inflammation.

 1. Recruit chronic cough patients and healthy volunteers as subjects.

 2. Help subjects to complete detailed history,physical examination,Hull airway reflux
 questionnaire,chest x-rays,induced sputum,blood routine test,pulmonary ventilation
 function test and histamine provocation test before they enter this study.

 3. Complete allyl isothiocynate(AITC) cough provocation test the day subjects enter the
 study,then complete capsaicin（CAP）cough provocation test after 3 days.

 4. To detect the substance P(SP),calcitonin gene-related peptide(CGRP),prostaglandin
 E2(PGE2),et al level in sputum supernatants.

 Secondly,to observe the distribution of TRPA1,TRPV1 channels and the relationship between it
 and cough reflex sensitivity.

 1）Recruit chronic cough patients and healthy volunteers and complete related examinations as
 mentioned before.

 2)Collect mucosa specimens from upper trachea via endobronchial biopsy,and airway epithelial
 cells from 2nd or 3rd order bronchi via brushing.

 3)Evaluate the expression level of TRPA1,TRPV1 of mucosa specimens of subjects by
 immunofluorescent assay and Image analysis software.

 4)Cultivate airway epithelial cells from subjects and evaluate the expression of TRPV1,TRPA1
 and functional changes of it.
Inclusion Criteria:

 chronic cough group:

 1. cough lasting ≥ 8 weeks,characterized by irritating dry cough.

 2. sensitive to fumes，dust,the odorous and cold air.

 3. with normal chest x-rays. 4.17-70 years old.

 5.without smoking history. healty controls group: 1.17-70 years old. 2.without smoking
 hitory or stop smoking for more than 2 years. 3.without chronic cough. 4.without chronic
 respiratory diseases. 5.without chronic heart, liver, kidney,and autoimmune disease. 6.with
 normal chest x-rays. 7.with normal pulmonary ventilation function,and histamine challenge
 test showed negative result.

 Exclusion Criteria:

 chronic cough group and healty controls group:

 1. with respiratory tract infection within 8 weeks.

 2. with chronic respiratory diseases or severe heart, liver, kidney,and autoimmune
 disease.

 3. using Angiotensin-Converting Enzyme
 Inhibitors(ACEI),bronchodilators,glucocorticosteroid,antihistaminics within one week.

 4. women during pregnancy or lactation.

 5. patients with malignant tumours.