Assessment of an Exhaled Breath Test to Detect Bronchiectasis

Study Overview
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Brief Summary
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To investigate whether the breath test is able to detect bronchiectasis using breathomics. This study was conducted with a prospective specimen collection, evaluator-blinded, case-controlled clinical study designed to evaluate the accuracy of breathomics to diagnosis of bronchiectasis in adults.

Detailed Description
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Bronchiectasis is a chronic airway inflammation with irreversible expansion of bronchial walls, which is characteristic by chronic cough, mucinous sputum, dyspnea and wheezing. High resolution CT (HRCT) combined with clinical manifestations is the main diagnostic method of bronchiectasis, but HRCT is expensive and radioactive. Therefore, it is urgent to develop a new technology to diagnose bronchiectasis. Exhaled breath may be a better tool for bronchiectasis detection because of its noninvasive nature. Many efforts have been made to develop breath tests for lung cancer, asthma and Helicobacter pylori infection. However, little studies pay attention to bronchiectasis. High-pressure photon ionization time-of-flight mass spectrometry (HPPI-TOFMS) is a promising tool for breath testing, because it is highly sensitive, does not require pretreatment of exhaled breath, and holds great tolerance for humidity. In our case-control diagnostic study, we investigated whether a breath test combining HPPI-TOFMS and a support vector machine (SVM) algorithm was able to distinguish patients with bronchiectasis from healthy individuals.

Official Title
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Assessment of an Exhaled Breath Test Using High-Pressure Photon Ionization Time-of-Flight Mass Spectrometry to Detect Bronchiectasis

Conditions
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Bronchiectasis

Intervention / Treatment
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* Diagnostic Test: an exhaled breath test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients were recruited according to the following inclusion criteria: (1) Age>18 years, the diagnosis of bronchiectasis need reference to the definition of idiopathic bronchiectasis according to British Thoracic Society in 2010 or 2012 China bronchiectasis expert consensus; (2) Patients are clinically diagnosed as acute attack (AE) and need hospitalization, that is, they have the following three or more clinical symptoms within 48 hours: Cough; Changes in the amount or character of sputum; Purulent sputum; Shortness of breath or decreased exercise tolerance; weakness hemoptysis; (3) Patient quit smoking for more than two years; (4) Willing to join in and sign the informed consent form. Control subjects were recruited according to the following inclusion criteria:(1) Age>18 years; (2) No history of any lung disease (except for the history of pneumonia in the past time and small pulmonary nodules); (3) Willing to join in and sign the informed consent form. Exclusion Criteria: Patients were excluded according to the following criteria: (1) Bronchiectasis is caused by known causes: previous respiratory tract infections (especially measles and pertussis in dead infants and children, immune function defects (such as hypoimmunoglobulinemia, chronic granulomatous diseases, complement defects, HIV, etc.), genetic factors (such as ciliary dyskinesia, cystic pulmonary fibrosis, cartilage defects, etc.), airway obstruction and repeated aspiration; (2) Patients with a history of other respiratory diseases (cystic fibrosis, allergic bronchopulmonary aspergillosis, asthma, 1-antitrypsin deficiency, pulmonary tuberculosis, COPD, lung cancer, interstitial lung disease)and atopic diseases were excluded; (3) Serious comorbidities (chronic renal failure, hepatic disease, etc.) ; (4) Patients who are currently smoking or have quit smoking for less than 2 years; (5) Women who are pregnant or preparing for pregnancy or breastfeeding; (6) Participated in other clinical trials within three months. Control subjects were excluded according to the following criteria: (1) Previous history of malignant tumor; (2) presence of active infections (such as tuberculosis, non-tuberculous mycobacterium disease) or liver disease; (3) women who are pregnant or preparing for pregnancy and are breastfeeding; (4) Current smoking, or smoking cessation less than 2 years.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with bronchiectasis<br>Diagnosis of bronchiectasis was performed using chest HRCT scans in suspected patients with coughing and expectoration, or long durations of haemoptysis. High-resolution images were obtained during full inspiration at 1-mm collimation and 10-mm intervals from the apex to the base of the lungs. The presence of bronchiectasis was confirmed based on the following criteria: 1) lack of tapering in the bronchi; 2) dilation of the bronchi where the internal diameter was larger than that of the adjacent pulmonary artery; or 3) visualisation of the peripheral bronchi within 1 cm of the costal pleural surface or the adjacent mediastinal pleural surface. | Diagnostic Test: an exhaled breath test<br>* All exhaled breath samples were collected by trained investigators following the same protocol. All participants fasted for at least 6 hours before breath collection. To reduce potential confounding factors, all participants were asked to not ingest spicy food, alcohol, or coffee the night before exhaled breath collection. Exhaled breath was collected in Tedlar air bags (DuPont de Nemours). The night before breath collection, the Tedlar bags were baked at 60 °C for 3 hours to fully release possible contaminants and continuously purged with high-purity nitrogen 4 times. Participants first gargled with pure water and then performed a single deep nasal inhalation followed by complete exhalation via their mouth into Tedlar bags. A total of 1000 mL of exhaled breath was collected from each participant.<br>|
| Healthy control group<br>Control group is healthy participants. | Diagnostic Test: an exhaled breath test<br>* All exhaled breath samples were collected by trained investigators following the same protocol. All participants fasted for at least 6 hours before breath collection. To reduce potential confounding factors, all participants were asked to not ingest spicy food, alcohol, or coffee the night before exhaled breath collection. Exhaled breath was collected in Tedlar air bags (DuPont de Nemours). The night before breath collection, the Tedlar bags were baked at 60 °C for 3 hours to fully release possible contaminants and continuously purged with high-purity nitrogen 4 times. Participants first gargled with pure water and then performed a single deep nasal inhalation followed by complete exhalation via their mouth into Tedlar bags. A total of 1000 mL of exhaled breath was collected from each participant.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The accuracy of breathomics to distinguish bronchiectasis from healthy people | The accuracy of breathomics to distinguish bronchiectasis from healthy people was measured by the sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve. | one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assessment of the bronchiectasis severity according to breathomics | The severity of bronchiectasis was based on the BSI score and E-FACED score. Multivariable Logistic Regression Analyses would be used for the relationship between breathomics and the severity of bronchiectasis. | 30 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Bronchiectasis; breathomics