Utility of Lung Clearance Index Score as a Noninvasive Marker of Deployment Lung Disease

Study Overview
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Brief Summary
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The purpose of this study is to learn more about new noninvasive ways of detecting lung disease in US Military personnel and people who worked as contractors during military operations in Iraq and Afghanistan. This study is looking at conducting a type of breathing test called the lung clearance index (LCI) test which is being investigated as a potential noninvasive way to detect the type of lung disease that may be seen in symptomatic deployers retuning from Iraq and Afghanistan.

Detailed Description
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The healthy control group will comprise volunteers who are at least 18 years of age, have no history of pre-existing lung disease, and report no respiratory illness in the four weeks preceding enrollment. The symptomatic deployers who have undergone lung biopsy and meet the case definition for deployment-related lung disease. A case of deployment-related lung disease is defined as the presence of unexplained chest symptoms in a deployer who, on a surgical lung biopsy, is found to have bronchiolitis or granulomatous pneumonitis without other known cause.

Official Title
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Utility of Lung Clearance Index Score as a Noninvasive Marker of Deployment Lung Disease

Conditions
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Bronchiolitis, Pneumonitis, Dyspnea

Intervention / Treatment
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* Other: Lung clearance index (LCI)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For the deployer group: presence of respiratory symptoms (cough, chest tightness, wheezing, shortness of breath or decreased exercise tolerance) following deployment history of deployment for Operation Iraqi Freedom, Operation Enduring Freedom or Operation New Dawn for greater than or equal to 6 weeks as either military personnel or a civilian contractor prior VATS biopsy-proven histologic abnormalities of small airways disease. For the control group: no history of pre-existing lung disease no respiratory illness in the four weeks preceding enrollment Exclusion Criteria: For the deployer group: If on clinical evaluation they were found to have asthma, vocal cord dysfunction or other explanations for their respiratory symptoms and did not need to undergo surgical lung biopsy for diagnosis. unable to provide informed consent pregnant subjects For the control group: pre-existing lung disease unable to provide informed consent pregnant subjects

Ages Eligible for Study
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Minimum Age: 18 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 |
| --- | --- |
| Health control group<br>Who are 18 years or older, have no history of pre-existing lung disease, and report no respiratory illness in the four weeks preceding enrollment. This study consist of one visit: If the potential subject meets the Inclusion and exclusion then they will have the LCI testing. | Other: Lung clearance index (LCI)<br>* LCI is determined by the number of lung volume turnovers necessary to clear the lungs of an inert tracer gas such as nitrogen that is inhaled at the beginning of the test. The LCI is calculated by determining the cumulative expired volume (CEV) and then dividing the CEV by the functional residual capacity. Values of less than7.0 indicate normal values while an LCI greater than 7.0 is associated with heterogeneity in ventilation and distal airway abnormalities. The ability to detect peripheral airway disease may make LCI a better modality for detecting distal airways abnormalities seen on lung histopathology but often missed on traditional pulmonary function testing.<br>|
| Deployment-related lung disease<br>Defined as the presence of unexplained chest symptoms in a deployer who, on surgical lung biopsy is found to have bronchiolitis or granulomatous pneumonitis without other known causes. This study consist of one visit: If the potential subject meets the Inclusion and exclusion then they will have the LCI testing. | Other: Lung clearance index (LCI)<br>* LCI is determined by the number of lung volume turnovers necessary to clear the lungs of an inert tracer gas such as nitrogen that is inhaled at the beginning of the test. The LCI is calculated by determining the cumulative expired volume (CEV) and then dividing the CEV by the functional residual capacity. Values of less than7.0 indicate normal values while an LCI greater than 7.0 is associated with heterogeneity in ventilation and distal airway abnormalities. The ability to detect peripheral airway disease may make LCI a better modality for detecting distal airways abnormalities seen on lung histopathology but often missed on traditional pulmonary function testing.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| LCI parameters in symptomatic deployers compared to normal adults to determine whether LCI is an early marker of lung injury. | Average of three acceptable trials | Up to 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between LCI score and the clinical characteristics of the population of deployers. | Comparison with pulmonary function testing and other clinical measures | Up to 24 months |