ATP Level and Cough Sensitivity to ATP in Subjects With Refractory/Unexplained Chronic Cough

ATP Level in Induced Sputum and Cough Sensitivity to ATP in Subjects With Refractory/Unexplained Chronic Cough

This is a cross-sectional study to investigate ATP level in induced sputum and cough sensitivity to ATP in subjects with refractory/unexplained chronic cough. 60 patients with refractory/unexplained chronic cough and 30 matched healthy controls were recruited. Demographic data, clinical characteristic, cough sacles and medical history records were collected. Cough chanllage(ATP and capsaicin) and ATP measurement in sputum were conducted.The difference of sputum ATP level between patients and control and the correlation between sputum ATP level and cough sensitivity to ATP were analyzed.

Study Overview

• Status: Completed
• Conditions: Refractory/Unexplained Chronic Cough

• Study Type: Observational
• Enrollment (Actual): 131

Contacts and Locations

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China
      • Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Subjects with chronic cough visiting cough clinics at the First Affiliated Hospital of Guangzhou Medical University would all be screened by the investigator. To be specific, RCC/UCC refers to a chronic cough: 1) without identifiable causes after throughout investigation; 2) persistent after empirical treatment to known causes; 3) persistent after treatment for positive conditions known to be associated with chronic cough. Age and gender matched healthy controls would be recruited.

The subject who meets the criteria and provides written informed consent is considered as eligible and enrolled into the study.

Description

Inclusion criteria for patients:

1. ≥18 years old
2. cough as sole symptom lasting ≥6 months
3. cough visual analogue score ≥30mm
4. diagnosed as RCC/UCC according to guidelines

Exclusion criteria for patients:

1. smoking currently or in the past 6 months, or a smoking history of >20 pack-year
2. a forced expiratory volume in 1 second/forced vital capacity ratio <70%;
3. use of inhaled/oral corticosteroid, bronchodilators, anti-allergic medicine, antitussive medicine or anti-reflux treatment in the past 1 week;
4. a history of acute respiratory infection in the past 4 weeks;
5. a history of severe disease (cancer, acute coronary syndrome and so on).

Healthy control aged ≥18 years old are included. Exclusion criteria are as follow:

1. smoking currently or in the past 6 months, or a smoking history of >20 pack-year
2. a forced expiratory volume in 1 second/forced vital capacity ratio <70%
3. a history of acute respiratory infection in the past 4 weeks
4. posstive findings of chest radiography
5. a history of chronic respiratory disease and allergic disease
6. any signs of cough hypersensitivity

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
refractory/unexplained chronic cough; Induced sputum test and cough challenge(ATP and capsaicin) were performed.
Healthy control; Induced sputum test and cough challenge(ATP and capsaicin ) were performed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ATP Level in Sputum Supernatant	ATP level in induced sputum in patients with refractory/unexplained chronic cough and healthy control	ATP concentrations were measured in all specimens on the day of the last participant's enrollment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ATP Cough Sensitivity	Cough sensitivity for ATP in patients with refractory/unexplained chronic cough and healthy control. Lowest concentration of ATP that provoked at least 5 coughs (C5) is used to indicate cough sensitivity.	Each subject underwent ATP cough challenge on the day of enrollment.

Collaborators and Investigators

• Sponsor: Kefang Lai
• Investigators: Study Chair: Kefang Lai, MD, PhD, Guangzhou Institute of Respiratory Health, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, National Center for Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University

Study record dates

Study Major Dates

• Study Start (Actual): May 16, 2022
• Primary Completion (Actual): January 24, 2024
• Study Completion (Actual): January 24, 2024

Study Registration Dates

• First Submitted: February 23, 2022
• First Submitted That Met QC Criteria: February 23, 2022
• First Posted (Actual): March 4, 2022

Study Record Updates

• Last Update Posted (Actual): May 11, 2025
• Last Update Submitted That Met QC Criteria: April 25, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: adenosine triphosphate; refractory/unexplained chronic cough; cough sensitivity
• Additional Relevant MeSH Terms: Immune System Diseases; Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Chronic Cough; Hypersensitivity; Cough
• Other Study ID Numbers: RCC-ATP

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No