Findings on High Resolution Computed Tomography in Symptomatic Veterans with Deployment-Related Lung Disease.

PURPOSE: Military deployment to dusty, austere environments in Southwest Asia and Afghanistan is associated with symptomatic airways diseases including asthma and bronchiolitis. The utility of chest high-resolution computed tomographic (HRCT) imaging in lung disease diagnosis in this population is poorly understood. We investigated visual assessment of HRCT for identifying deployment-related lung disease compared with healthy controls. MATERIALS AND METHODS: Chest HRCT images from 46 healthy controls and 45 symptomatic deployed military personnel with clinically confirmed asthma and/or biopsy-confirmed distal lung disease were scored by 3 independent thoracic radiologists. We compared demographic and clinical characteristics and frequency of imaging findings between deployers and controls, and between deployers with asthma and those with biopsy-confirmed distal lung disease, using χ2, Fisher exact or t tests, and logistic regression where appropriate. We also analyzed inter-rater agreement for imaging findings. RESULTS: Expiratory air trapping was the only chest CT imaging finding that was significantly more frequent in deployers compared with controls. None of the 24 deployers with biopsy-confirmed bronchiolitis and/or granulomatous pneumonitis had HRCT findings of inspiratory mosaic attenuation or centrilobular nodularity. Only 2 of 21 with biopsy-proven emphysema had emphysema on HRCT. CONCLUSIONS: Compared with surgical lung biopsy, visual assessment of HRCT showed few abnormalities in this small cohort of previously deployed symptomatic veterans with normal or near-normal spirometry.

Small airways and airspace inflammation and injury distinguish lung histopathology in deployed military personnel from healthy and diseased lungs.

The link between military deployment to Southwest Asia and Afghanistan, and the risk for lung disease, including bronchiolitis, is increasingly well-recognized. However, histopathologic features that distinguish deployment-related lung diseases from other diseases affecting the small airways and airspaces are uncertain. A computer-based scoring system was developed to characterize surgical lung biopsy findings in 65 soldiers with persistent respiratory symptoms following military deployment ("deployers"). Deployer lung biopsies were compared to those from 8 patients with chronic hypersensitivity pneumonitis (cHP), 10 with smoking-related respiratory bronchiolitis, 11 with autoimmune or post-transplant obliterative bronchiolitis, and 10 normal donor lungs. Upper, middle, and lower lobe-specific findings in deployer samples were analyzed to inform optimum biopsy location choice for future patients. Surgical lung biopsies from symptomatic deployed military service members were distinguished by a combination of small airways abnormalities including smooth muscle hypertrophy (SMH), peribronchiolar metaplasia (PBM), and lymphocytic inflammation, often with constrictive/obliterative (C/O) and/or respiratory bronchiolitis (43.1%), granulomatous inflammation (38.5%), and moderate/severe emphysema (46.2%, mainly in nonsmokers). Lymphocytic pleural inflammation was common (89.2%), and vascular abnormalities occurred in nearly one-third. Histopathologic features in deployers were most strongly overlapping with cases of cHP, both showing granulomatous inflammation, PBM, and emphysema. SMH along with C/O and respiratory bronchiolitis were common in deployers but not in cHP cases. In deployers, there were significantly higher odds of small airways injury in the lower lobe compared with upper lobe samples.

Semiquantitative Chest Computed Tomography Assessment Identifies Expiratory Central Airway Collapse in Symptomatic Military Personnel Deployed to Iraq and Afghanistan.

PURPOSE: We noted incidental findings on chest computed tomography (CT) imaging of expiratory central airway collapse (ECAC) in dyspneic patients after military deployment to southwest Asia (mainly Iraq and Afghanistan). We developed a standardized chest CT protocol with dynamic expiration to enhance diagnostic reliability and investigated demographic, clinical, and deployment characteristics possibly associated with ECAC. MATERIALS AND METHODS: We calculated ECAC in 62 consecutive post-9/11 deployers with dyspnea who underwent multi-detector chest CT acquisition. ECAC was defined as ≥70% reduction in the cross-sectional tracheal area at dynamic expiration. We compared demographics (age, smoking, body mass index), comorbid conditions (gastroesophageal reflux, obstructive sleep apnea [OSA]), and clinical findings (air trapping, forced expiratory volume in 1 second percent predicted) in deployers with and without ECAC. We examined associations between ECAC and forced expiratory volume in 1 second percent predicted, air trapping, OSA, deployment duration, and blast exposure. RESULTS: Among 62 consecutive deployers with persistent dyspnea, 37% had ECAC. Three had severe (>85%) collapse. Those with ECAC were older (mean age 46 vs. 40 y, P=0.02), but no other demographic or clinical characteristics were statistically different among the groups. Although not statistically significant, ECAC odds were 1.5 times higher (95% confidence interval: 0.9, 2.5) for each additional year of southwest Asia deployment. Deployers with ECAC had 1.6 times greater odds (95% confidence interval: 0.5, 4.8) of OSA. CONCLUSIONS: Findings suggest that ECAC is common in symptomatic southwest Asia deployers. Chest high-resolution CT with dynamic expiration may provide an insight into the causes of dyspnea in this population, although risk factors for ECAC remain to be determined. A standardized semiquantitative approach to CT-based assessment of ECAC should improve reliable diagnosis in dyspneic patients.

Multiple breath washout: A noninvasive tool for identifying lung disease in symptomatic military deployers.

RATIONALE: Military deployments to austere environments since November 9, 2001 may put "deployers" at risk for respiratory disease. Sensitive, noninvasive tools for detecting large and small airways injury are needed to identify early disease and help inform management for this at-risk population. OBJECTIVES: We examined multiple breath washout (MBW) as a tool for identifying deployment-related airways disease and assessed host and exposure risk factors compared to healthy controls. METHODS: Between March 2015 and March 2020, 103 healthy controls and 71 symptomatic deployers with asthma and/or distal lung disease completed a questionnaire, spirometry and MBW testing. SAS v. 9.4 was used to compare MBW parameters between deployers and controls via univariate analyses and adjusted for demographic factors using multiple linear regression. MEASUREMENTS AND MAIN RESULTS: Deployers were significantly more likely than controls to have an abnormal lung clearance index (LCI) score indicating global ventilation inhomogeneity. Adjusting for sex, smoking status, smoking pack-years and body mass index, LCI scores were significantly more abnormal among those with deployment-related asthma and distal lung disease compared to controls. The unadjusted variable Sacin (a marker of ventilation inhomogeneity in the acinar airways) was higher and thus more abnormal in those with both proximal and distal airways disease. Deployers who reported more frequent exposure to explosive blasts had significantly higher LCI scores. CONCLUSIONS: This study demonstrates the utility of MBW in evaluating exposure-related airways disease in symptomatic military personnel following deployment to austere environments, and is the first to link exposure to explosive blasts to measurable small airways injury.

Multiple breath washout test data for healthy controls.

This article includes pulmonary function data collected via multiple breath nitrogen washout for 103 healthy U.S. adults recruited at National Jewish Health in Denver, Colorado. Testing was performed by certified technicians and reviewed by expert pulmonologists for quality and consistency. Data were collected from a diverse population that included 52 males and 51 females with an average age of 39 years (range 20-77 years). Participants were of non-Hispanic White (85%), African-American/Black (6%), Hispanic (4%), more than one race (4%) or American Indian/Alaskan Native (1%) race/ethnicity. The majority were never smokers (85%), but 12% were former smokers and 3% were current smokers. Height, weight, and body mass index (BMI) were collected in addition to multiple breath washout (MBW) test parameters such as the lung clearance index (LCI) score.

Silicosis: An Update and Guide for Clinicians.

This overview provides an update on silicosis epidemiology with review of exposures and emerging trends in acute and accelerated silicosis in the twenty-first century. The silicosis epidemics in mining, denim sandblasting, and engineering stone industries are highlighted. Clinical presentations of silicosis and silica-related conditions such as autoimmune, kidney, and mycobacterial disease, as well as lung cancer, are discussed. Important aspects of the new OSHA 2017 Silica Standard are presented. This review also includes practical guidance for clinicians to address questions that may arise when evaluating silica-exposed patients and to the public health responses needed following a diagnosis of silica-related disease.

Respiratory Diseases in Post-9/11 Military Personnel Following Southwest Asia Deployment.

OBJECTIVE: Persistent respiratory symptoms following post-9/11 military deployment to Iraq and Afghanistan are well-recognized, but the spectrum of respiratory diseases remains poorly characterized. This study describes deployment-related respiratory diseases and the diagnostic utility of resting and exercise pulmonary function testing. METHODS: Between 2009 and 2017, 127 consecutive military workers ("deployers") with new-onset respiratory symptoms underwent clinical evaluation. Deployment-related respiratory diseases were classified as proximal and/or distal. Using descriptive statistics and logistic regression, we analyzed lung function parameters associated with deployment-related distal lung disease (DDLD). RESULTS: Common deployment-related respiratory diseases included asthma (31.5%), intermittent laryngeal obstruction (14.2%), rhinosinusitis (15%), and DDLD (68.5%). Decreased diffusion capacity (odds ratio [OR] = 4.6, 95% confidence interval [CI]: 1.4 to 15.1, P = 0.01) was significantly associated with DDLD. CONCLUSIONS: A comprehensive diagnostic approach may identify a spectrum of proximal and distal respiratory diseases that can occur in symptomatic post-9/11 deployers, requiring a personalized approach to care.

Military Occupational Specialty Codes: Utility in Predicting Inhalation Exposures in Post-9/11 Deployers.

OBJECTIVE: The aim of this study was to examine military occupational specialty (MOS) codes to identify those at risk from inhalation exposures during Southwest Asia deployment. METHODS: Exposure intensity to diesel exhaust, sandstorms, burn pit smoke, combat dust, and occupational vapors/dusts/gases/fumes (VDGF) were scored for all Army/Marine MOS codes by an expert panel. Based on MOS code, panel-rated exposure scores were compared with questionnaire data from military personnel with postdeployment respiratory illnesses. RESULTS: All exposures except VDGF were rated higher (range P < 0.0001 to P = 0.003) for combat versus noncombat MOS codes. Deployers with respiratory illnesses reported more intense exposure to diesel exhaust (P < 0.0001), burn pit smoke (P < 0.0001), and sandstorms (P = 0.005) compared with panel raters. These deployers clustered in MOS codes rated highest for inhalation hazard exposure intensity. CONCLUSIONS: MOS codes are useful in identifying high-risk military occupations where medical surveillance and exposure control should be focused.

Severe Silicosis in Engineered Stone Fabrication Workers - California, Colorado, Texas, and Washington, 2017-2019.

Silicosis is an incurable occupational lung disease caused by inhaling particles of respirable crystalline silica. These particles trigger inflammation and fibrosis in the lungs, leading to progressive, irreversible, and potentially disabling disease. Silica exposure is also associated with increased risk for lung infection (notably, tuberculosis), lung cancer, emphysema, autoimmune diseases, and kidney disease (1). Because quartz, a type of crystalline silica, is commonly found in stone, workers who cut, polish, or grind stone materials can be exposed to silica dust. Recently, silicosis outbreaks have been reported in several countries among workers who cut and finish stone slabs for countertops, a process known as stone fabrication (2-5). Most worked with engineered stone, a manufactured, quartz-based composite material that can contain >90% crystalline silica (6). This report describes 18 cases of silicosis, including the first two fatalities reported in the United States, among workers in the stone fabrication industry in California, Colorado, Texas, and Washington. Several patients had severe progressive disease, and some had associated autoimmune diseases and latent tuberculosis infection. Cases were identified through independent investigations in each state and confirmed based on computed tomography (CT) scan of the chest or lung biopsy findings. Silica dust exposure reduction and effective regulatory enforcement, along with enhanced workplace medical and public health surveillance, are urgently needed to address the emerging public health threat of silicosis in the stone fabrication industry.

Childhood Sexual Abuse and Lifetime Aggression.

This study of college undergraduates (N = 873) examined three hypotheses regarding associations between childhood sexual abuse and lifetime aggression: 1) childhood sexual abuse was expected to account for unshared variance in the lifetime aggression indicators after controlling for the potential effects of parental physical abuse, sibling physical abuse, exposure to intimate partner violence, peer bullying, and respondent age; 2) childhood sexual abuse associations were expected to be relatively stronger among the women than the men; 3) childhood sexual abuse links to lifetime aggression were expected to vary as a function of age of victimization (adolescent < childhood < dual-age victims). Aggression histories varied widely with over 20% reporting prior injuries inflicted on others (3.2% > five injuries). Sexual abuse links to aggression tended to be stronger (p < .001) for the women than the men, and rates of aggression were higher when sexual abuse recurred across both childhood and adolescence. Partial support was found for all three hypotheses.