Tracheobronchomalacia and Air Trapping after Mustard Gas Exposure

Respiratory function after 30+ years following sulfur mustard exposure in survivors in Sweden

Background

Sulfur mustard (SM) exposure causes acute and chronic respiratory diseases. The extent of small airway dysfunction (SAD) in individuals exposed to SM is unclear. This study evaluated and compared SAD in SM-exposed and SM-unexposed participants using noninvasive lung function tests assessing small airway function.

Methods

This retrospective cohort study involved SM-exposed (n = 15, mean age: 53 ± 8 years) and SM-unexposed (n = 15, mean age: 53 ± 7 years) Kurdish-Swedish individuals in Sweden. Small airway resistance and reactance were assessed using impulse oscillometry (IOS). Nitrogen (N2) multiple breath washout (MBW) was employed to assess lung ventilation heterogeneity. The gas-exchanging capacity of the lungs was assessed using the diffusing capacity of the lungs for the carbon monoxide (DLCO) test. Lung function outcomes were reported as absolute values and z-scores. Group comparisons were performed using the Mann-Whitney U test.

Results

No statistically significant differences in age, height, or body mass index were observed between the two groups. IOS showed significantly increased small airway resistance, while N2MBW exhibited significantly increased global and acinar ventilation heterogeneity in SM-exposed individuals compared to that in unexposed individuals. SAD was identified in 14 of 15 SM-exposed individuals, defined as at least one abnormal IOS difference between resistance at 5 and 20 Hz (R5-R20) and/or area of reactance (AX) or N2MBW lung's acinar zone (Sacin), and DLCO adjusted to the alveolar volume (DLCO/VA) outcome. Of these 14 individuals, only 5 demonstrated concordant findings across the IOS and N2MBW tests.

Conclusion

Exposure to SM was positively associated with long-term impairment of respiratory tract function in the small airways in the majority of the previously SM-exposed individuals in the present study. Furthermore, both IOS and N2MBW should be employed to detect SAD in SM-exposed survivors as they provide complementary information. Identifying and characterizing the remaining pathology of the small airways in survivors of SM exposure is a first step toward improved treatment and follow-up.

Computer-assisted evaluation of small airway disease in CT scans of Iran-Iraq war victims of chemical warfare by a locally developed software: comparison between different quantitative methods

OBJECTIVE

Diagnosis of small airway disease on computed tomography (CT) scans is challenging in patients with a history of chemical warfare exposure. We developed a software package based on different methodologies to identify and quantify small airway disease in CT images. The primary aim was to identify the best automatic methodology for detecting small airway disease in CT scans of Iran-Iraq War victims of chemical warfare.

METHODS

This retrospective case-control study enrolled 46 patients with a history of chemical warfare exposure and 27 controls with inspiratory/expiratory (I/E) CT scans and spirometry tests. Image data were automatically segmented, and inspiratory images were registered into the expiratory images' frame using the locally developed software. Parametric response mapping (PRM) and air trapping index (ATI) mapping were performed on the CT images. Conventional QCT methods, including expiratory/inspiratory mean lung attenuation (E/I MLA) ratio, normal density E/I (ND E/I) MLA ratio, attenuation volume Index (AVI), %low attenuation areas (LAA) < -856 in exhale scans, and %LAA < -950 in inhale scans were also computed. QCT measurements were correlated with spirometry results and compared across the two study groups.

RESULTS

The correlation analysis showed a significant negative relationship between three air trapping (AT) measurements (PRM, ATI, and %LAAExp < -856) and spirometry parameters (Fev1, Fvc, Fev1/Fvc, and MMEF). Moreover, %LAAExp < -856 had the highest significant negative correlation with Fev1/Fvc (r = -0.643, P-value < 0.001). Three AT measurements demonstrated a significant difference between the study groups. The E/I ratio was also significantly different between the two groups (P-value < 0.001). Binary logistic regression models showed PRMFsad, %LAAExp < -856, and ATI as significant and strong predictors of the study outcome. Optimal cut-points for PRMFsad = 19%, %LAAExp < -856 = 23%, and ATI = 27% were identified to classify the participants into two groups with high accuracy.

CONCLUSION

QCT methods, including PRM, ATI, and %LAAExp < -856 can greatly advance the identification and quantification of SAD in chemical warfare victims. The results should be verified in well-designed prospective studies involving a large population.

A Computer-based Analysis for Identification and Quantification of Small Airway Disease in Lung Computed Tomography Images: A Comprehensive Review for Radiologists

Computed tomography (CT) imaging is being increasingly used in clinical practice for detailed characterization of lung diseases. Respiratory diseases involve various components of the lung, including the small airways. Evaluation of small airway disease on CT images is challenging as the airways cannot be visualized directly by a CT scanner. Small airway disease can manifest as pulmonary air trapping (AT). Although AT may be sometimes seen as mosaic attenuation on expiratory CT images, it is difficult to identify diffuse AT visually. Computer technology advances over the past decades have provided methods for objective quantification of small airway disease on CT images. Quantitative CT (QCT) methods are being rapidly developed to quantify underlying lung diseases with greater precision than subjective visual assessment of CT images. A growing body of evidence suggests that QCT methods can be practical tools in the clinical setting to identify and quantify abnormal regions of the lung accurately and reproducibly. This review aimed to describe the available methods for the identification and quantification of small airway disease on CT images and to discuss the challenges of implementing QCT metrics in clinical care for patients with small airway disease.

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.

Expiratory reactance abnormalities in patients with expiratory dynamic airway collapse: a new application of impulse oscillometry

Expiratory dynamic airways collapse (EDAC) is a condition that affects the central airways; it is not well characterised physiologically, with relatively few studies. We sought to characterise impulse oscillometry (IOS) features of EDAC in patients with normal spirometry. Expiratory data were hypothesised to be the most revealing. In addition, we compared IOS findings in chronic obstructive pulmonary disease (COPD) patients with and without EDAC.

EDAC was identified at bronchoscopy as 75–100% expiratory closure at the carina or bilateral main bronchi. Four patient groups were compared: controls with no EDAC and normal lung function; lone EDAC with normal lung function; COPD-only patients; and COPD patients with EDAC.

38 patients were studied. Mean IOS data z-scores for EDAC compared to controls showed significantly higher reactance (X) values including X at 5 Hz, resonance frequency and area under the reactance curve (A_X). EDAC showed significantly greater expiratory/inspiratory differences in all IOS data compared to controls. Stepwise logistic regression showed that resonant frequency best discriminated between EDAC and normal control, whereas classification and regression tree analysis found A_X ≥3.523 to be highly predictive for EDAC in cases with normal lung function (14 out of 15 cases, and none out of eight controls).

These data show a new utility of IOS: detecting EDAC in patients with normal lung function.

Central airway expiratory dynamic airway collapse can be “silent” on breathing tests, but impulse oscillometry can reveal ithttp://ow.ly/9oIb30lIOka

Relationship of serum levels of interleukin 6, interleukin 8, and C-reactive protein with forced expiratory volume in first second in patients with mustard lung and chronic obstructive pulmonary diseases: systematic review and meta-analysis

INTRODUCTION

The chronic systemic inflammation is a result of releasing inflammatory cytokines from the cells relating to the body immunity system and chronic activation of the innate immunity system.

AIM

To evaluate the relationship among serum levels of interleukin 6 (IL-6), interleukin 8 (IL-8), C-reactive protein (CRP) with forced expiratory volume in 1st s (FEV1) in patients with mustard lung (ML) and chronic obstructive pulmonary diseases (COPD).

MATERIAL AND METHODS

A published literature search was performed through SID, web of science, ISI, Science Direct, Scopus, Medline, and PubMed databases for articles published in English. The correlation coefficient (r) and 95% confidence intervals (95% CIs) were calculated using random or fixed effects models. Heterogeneity was assessed using χ2 and I2 statistics.

RESULTS

In total, 4 published studies were included in the final analysis. Using the random-effect model, meta-analysis showed that the r was -0.052 (95% CI: -0.14-0.049, p = 0.28) at serum level of IL-8, serum levels of CRP and FEV1 in these results were r = -0.13, p = 0.012, serum levels of tumor necrosis factor (TNF) and FEV1 levels were r = -0.39, p = 0.03 in the conducted studies on mustard lung patients. The IL-6 serum level was explored in COPD patients. The results of the given studies in these patients are r = -0.006, 95% CI: -0.37-0.15, and p = 0.44.

CONCLUSIONS

In this meta-analysis, there was evidence that serum levels of CRP and TNF have been significantly increased in chronic obstructive pulmonary diseases compared to the healthy control group, which signifies the presence of systemic inflammation in ML and COPD patients.

Progressive delayed respiratory complications of sulfur mustard poisoning in 43 Iranian veterans, three decades after exposure

The most common delayed complication of sulfur mustard (SM) poisoning has been observed in the respiratory tracts. It was thus aimed to investigate the delayed respiratory complications in SM-exposed patients around 25 years before the study. Forty-three veterans with more than 25% disability of due to SM poisoning were investigated. Clinical examinations as well as pulmonary function test (PFT) were performed. High-resolution computed tomography (HRCT) of the lungs was done as clinically indicated. Triad of chronic cough, dyspnea, and expectoration were the most common symptoms that were recorded in 88.2%, 88.2%, and 64.7% of the patients, respectively. PFT abnormalities were detected in 44.18% of the patients. Restrictive pattern was the most common (41.86%), while pure obstructive pattern did not detect at all. Mixed pattern was significantly correlated with higher disability percentages among the veterans ( p < 0.001). Significant reverse correlation between the disability percentages and forced expiratory volume in 1 s/forced vital capacity ratio was obtained ( p = 0.010, r = −0.389). Air trapping was the most common abnormality in HRCTs (50%). Bronchiectasis (25%), pulmonary fibrosis (25%), and ground-glass attenuation (16.66%) were other common HRCT findings. Comparing with the previous studies on these patients, more restrictive and mixed pattern were observed. Moreover, bronchiolitis, bronchiectasis, and lung fibrosis were the main pathological findings in these patients.

Sulfur mustard inhalation: mechanisms of injury, alteration of coagulation, and fibrinolytic therapy

Acute lung injury due to sulfur mustard (SM) inhalation causes the formation of airway fibrin casts that obstruct airways at multiple levels, leading to acute respiratory failure and death. These pathophysiological effects are seen in rodent models of acute SM vapor inhalation, as well as in human victims of acute SM inhalation. In rat models, the initial steps in activation of the coagulation system at extravascular sites depend on tissue factor (TF) expression by airway cells, especially in the microparticle fraction, and these effects can be inhibited by TF pathway inhibitor protein. Not only does the procoagulant environment of the acutely injured lung contribute to airway cast formation, but these lesions persist in airways because of the activation of multiple antifibrinolytic pathways, including plasminogen activator inhibitor-1, thrombin-activatable fibrinolysis inhibitor, and α2-antiplasmin. Airway administration of tissue plasminogen activator can overwhelm these effects and save lives by preventing fibrin-dependent airway obstruction, gas-exchange abnormalities, and respiratory failure. In human survivors of SM inhalation, fibrotic processes, including bronchiolitis obliterans and interstitial fibrosis of the lung, are among the most disabling chronic lesions. Antifibrotic therapies may prove useful in preventing either or both of these forms of chronic lung damage.

Long-term pulmonary complications of chemical weapons exposure in former poison gas factory workers

CONTEXT

Sulfur mustard (SM) and lewisite are vesicant chemical warfare agents that can cause skin blistering and chronic lung complications. During 1929-1945, a Japanese factory produced poisonous gases, which included SM, lewisite and other chemical weapons. The aim of this study was to investigate the chest computed tomography (CT) findings among long-term survivors who worked at this factory.

METHODS

During 2009-2012, we evaluated chest CT findings from 346 long-term survivors who worked at the poison gas factory. Skin lesions were used as an indicator of significant exposure to vesicant agents.

RESULTS

Among the 346 individuals, 53 (15%) individuals experienced skin lesions while working at the factory, and chest CT revealed abnormal findings in 179 individuals (52%). Emphysema was the most common CT finding and was observed in 75 individuals (22%), while honeycombing was observed in 8 individuals (2%). Emphysema and honeycombing were more prevalent among individuals with skin lesions, compared to individuals without skin lesions. Multivariate analyses revealed significant associations between the presence of emphysema and skin lesions (p = 0.008). Among individuals who never smoked, individuals with skin lesions (n = 26) exhibited a significantly higher rate of emphysema, compared to individuals without skin lesions (n = 200) (35% versus 7%, respectively; p < 0.001).

CONCLUSION

Among the long-term survivors who worked at the poison gas factory, a history of skin lesions was associated with the presence of emphysema, even among never smokers, which suggests that emphysema might be a long-term complication of exposure to chemical warfare agents.

The footprint of TGF-β in airway remodeling of the mustard lung

Mustard lung is a major pulmonary complication in individuals exposed to sulfur mustard (SM) gas during the Iran-Iraq war. It shares common pathological and clinical features with some chronic inflammatory lung disorders, particularly chronic obstructive pulmonary disease (COPD). Airway remodeling, which is one of the main causes of lung dysfunction and the dominant phenomenon of chronic pulmonary diseases, is seen in the mustard lung. Among all mediators involved in the remodeling process, the transforming growth factor (TGF)-β plays a pivotal role in lung fibrosis and consequently in the airway remodeling. Regarding the high levels of this mediator detected in mustard lung patients, in the present study, we have discussed the possible roles of TGF-β in airway remodeling (including epithelial layer damage, subepithelial fibrosis and angiogenesis). Finally, based on TGF-β targeting, we have reviewed new airway remodeling therapeutic approaches.

Role of nicotinamide adenine dinucleotide phosphate oxidase in mediating vesicant-induced interleukin-6 secretion in human airway epithelial cells

Aerosolized exposure to the chemical warfare vesicant sulfur mustard and its analog nitrogen mustard (HN2) is known to induce airway lesions associated with secretion of proinflammatory cytokines such as IL-6. We have shown recently that HN2 challenge induced IL-6 secretion in human airway epithelial cells, a process mediated via epidermal growth factor receptor (EGFR) signaling. In this study, we evaluated the role of redox signaling in regulating HN2-induced, EGFR-mediated IL-6 secretions in primary cultured normal human bronchial epithelial cells (NHBECs) in the air-liquid interface. HN2-induced EGFR phosphorylation and IL-6 secretion in NHBECs were inhibited by the antioxidant N-acetyl-L-cysteine (NAC) and by the flavoprotein inhibitor diphenyleneiodonium chloride (DPI). These observations suggested that the inflammatory response in NHBECs after HN2 challenge was mediated via oxidative stress. HN2 exposure induced increased reactive oxygen species (ROS) formation and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in NHBECs, findings that were inhibited by NAC and DPI treatment. Among NADPH oxidase isoforms, mRNA expression of dual oxidase (DUOX)1 and DUOX2 were up-regulated by HN2. Furthermore, knockdown of DUOX1 or DUOX2 by short hairpin RNA resulted in inhibition of ROS generation, EGFR pathway activation, and IL-6 secretion in NHBECs. These results provide evidence that redox signaling plays a pivotal role in the HN2-induced airway inflammation and underscore the importance of DUOX1 and DUOX2 in vesicant-induced IL-6 secretion in human airway epithelial cells.

Assessing the relationship of paraoxonase-1 Q192R polymorphisms and the severity of lung disease in SM-exposed patients

Late respiratory complications in patients suffering from pulmonary lesions due to sulfur mustard (SM) gas are asthma, chronic obstructive pulmonary disease and bronchiectasis. Recently PON1 antioxidant activity draws attention as the enzyme which prevents the oxidation of lipoproteins during oxidative stress. In this study we aimed to investigate PON1 192 polymorphisms and paraoxonase and arylesterase activity in the serum of SM-exposed lung disease patients. Also, we examined the detection of PON1 and apoA1 proteins in BAL fluid. 101 male patients were included who were categorized to three groups of mild, moderate and severe suffering from pulmonary lesions due to SM. Significant reduction in paraoxonase activity [Healthy: 412.46 ± 89.1 U/L, Severe: 89.66 ± 20.7 U/L] (p < 0.0001) and arylesterase activity [Healthy: 25826.4 ± 4425.23 U/L, Severe: 16760.43 ± 3814.9 U/L] (p < 0.0001) with increase in severity of disease was demonstrated statistically. With respect to the distribution of the PON1 polymorphism, the RR genotype was more frequent in severe patients [37.2%] than healthy group [10%] (p < 0.05) and no significant regression was found between genotype and PON1 activity. On the other hand, the results of PON1 and apoA1 detection illustrated that only apoA1 protein was found in BAL fluid. According to our findings it seems that increase in the stress oxidative in chemical injured veterans with pulmonary complications comes with reduction in PON1 enzyme activity and appearance of RR genotype rises up with the increase in disease severity. Since a significant correlation between enzyme activity and genotype was not observed altering these two variables with each other requires more studies.

A clinicopathological approach to sulfur mustard-induced organ complications: a major review

CONTEXT

Sulfur mustard (SM), with an old manufacturing history still remains as potential threat due to easy production and extensive effects.

OBJECTIVES

Increasing studies on SM indicates the interest of researchers to this subject. Almost all human body organs are at risk for complications of SM. This study offers organ-by-organ information on the effects of SM in animals and humans.

METHODS

The data sources were literature reviews since 1919 as well as our studies during the Iraq-Iran war. The search items were SM and its all other nomenclatures in relation to, in vivo, in vitro, humans, animals, eye, ocular, ophthalmic, lungs, pulmonary, skin, cutaneous, organs and systemic. Amongst more than 1890 SM-related articles, 257 more relevant clinicopathologic papers were selected for this review.

RESULTS

SM induces a vast range of damages in nearly all organs. Acute SM intoxication warrants immediate approach. Among chronic lesions, delayed keratitis and blindness, bronchiolitis obliterans and respiratory distress, skin pruritus, dryness and cancers are the most commonly observed clinical sequelae.

CONCLUSION

Ocular involvements in a number of patients progress toward a severe, rapid onset form of keratitis. Progressive deterioration of respiratory tract leads to "mustard lung". Skin problems continue as chronic frustrating pruritus on old scars with susceptibility to skin cancers. Due to the multiple acute and chronic morbidities created by SM exposure, uses of multiple drugs by several routes of administrations are warranted.

A review on delayed toxic effects of sulfur mustard in Iranian veterans

Iranian soldiers were attacked with chemical bombs, rockets and artillery shells 387 times during the 8-years war by Iraq (1980-1988). More than 1,000 tons of sulfur mustard gas was used in the battlefields by the Iraqis against Iranian people. A high rate of morbidities occurred as the result of these attacks. This study aimed to evaluate the delayed toxic effects of sulfur mustard gas on Iranian victims. During a systematic search, a total of 193 (109 more relevant to the main aim) articles on sulfur mustard gas were reviewed using known international and national databases. No special evaluation was conducted on the quality of the articles and their publication in accredited journals was considered sufficient. High rate of morbidities as the result of chemical attacks by sulfur mustard among Iranian people occurred. Iranian researchers found a numerous late complications among the victims which we be listed as wide range of respiratory, ocular, dermatological, psychological, hematological, immunological, gastrointestinal and endocrine complications, all influenced the quality of life of exposed victims. The mortality rate due to this agent was 3%. Although, mortality rate induced by sulfur mustard among Iranian people was low, variety and chronicity of toxic effects and complications of this chemical agent were dramatic.

Treatment for sulfur mustard lung injuries; new therapeutic approaches from acute to chronic phase

Objective

Sulfur mustard (SM) is one of the major potent chemical warfare and attractive weapons for terrorists. It has caused deaths to hundreds of thousands of victims in World War I and more recently during the Iran-Iraq war (1980–1988). It has ability to develop severe acute and chronic damage to the respiratory tract, eyes and skin. Understanding the acute and chronic biologic consequences of SM exposure may be quite essential for developing efficient prophylactic/therapeutic measures. One of the systems majorly affected by SM is the respiratory tract that numerous clinical studies have detailed processes of injury, diagnosis and treatments of lung. The low mortality rate has been contributed to high prevalence of victims and high lifetime morbidity burden. However, there are no curative modalities available in such patients. In this review, we collected and discussed the related articles on the preventive and therapeutic approaches to SM-induced respiratory injury and summarized what is currently known about the management and therapeutic strategies of acute and long-term consequences of SM lung injuries.

Method

This review was done by reviewing all papers found by searching following key words sulfur mustard; lung; chronic; acute; COPD; treatment.

Results

Mustard lung has an ongoing pathological process and is active disorder even years after exposure to SM. Different drug classes have been studied, nevertheless there are no curative modalities for mustard lung.

Conclusion

Complementary studies on one hand regarding pharmacokinetic of drugs and molecular investigations are mandatory to obtain more effective treatments.

Tracheobronchomalacia in adults

Severe, diffuse tracheobronchomalacia (TBM) is an underrecognized cause of dyspnea, recurrent respiratory infections, cough, secretion retention, and even respiratory insufficiency. Patients often have comorbidities, such as asthma or chronic obstructive pulmonary disease, and inappropriate treatment for these conditions may precede eventual recognition of TBM by months or years. Most of these patients have an acquired form of TBM in which the etiology in unknown. Diagnosis of TBM is made by airway computed tomography scan and flexible bronchoscopy with forced expiration. The prevailing definition of TBM as a 50% reduction in cross-sectional area is nonspecific, with a high proportion of healthy volunteers meeting this threshold. The clinically significant threshold is complete or near-complete collapse of the airway. Airway stenting may treat TBM, although complications resulting from indwelling prostheses often limit the durability of stents. Surgical stabilization of the airway by posterior splinting (tracheobronchoplasty) effectively and permanently corrects malacic airways. Proper surgical selection is facilitated by a short-term stent trial.

Plasma proteomic profile of sulfur mustard exposed lung diseases patients using 2-dimensional gel electrophoresis

Introduction

Sulfur mustard "bis (2-chlroethyl) sulphide" (SM) is a chemical warfare agent that remains a threat to human health. The aim of this study was to identify protein expression signature or biomarkers that reflect chronic lung damages induced by SM exposure.

Methods

Prior to analysis, plasma was fractionated using ethanol precipitation. Using two dimensional SDS-PAGE; fractionated protein profiles of 20 healthy and 20 exposed patients with lung diseases were established. Selected protein spots were successfully identified with MALDI TOF MS/MS.

Results

The results show that α1 haptoglobin isoforms were detected in plasma of the all lung disease patients but none of the healthy controls. Amyloid A1 isoforms was also detected in plasma of the lung disease patients but none of the healthy controls. Moreover, low molecular weight proteins were enriched in ethanol supernatant compared to ethanol precipitate.

Conclusion

Our present results and previous studies suggest that ongoing tissue remodeling is involved in SM exposed lung damage patients. These finding might improve patient care and suitable therapies.

[An unusual association: tracheobronchomegaly with a normal pulmonary function test]

Tracheobronchomegaly is a rare condition characterised by marked dilation of the trachea and the main bronchi. The clinical presentation of this disease is nonspecific and the diagnosis is based on the radiological features, especially computed tomography of chest. Pulmonary function tests are often abnormal showing airflow limitation with increased residual volume. The authors report a rare case of a 31-year-old man presenting tracheobronchomegaly is normal pulmonary function test.

Mustard gas toxicity: the acute and chronic pathological effects

Ever since it was first used in armed conflict, mustard gas (sulfur mustard, MG) has been known to cause a wide range of acute and chronic injuries to exposure victims. The earliest descriptions of these injuries were published during and in the immediate aftermath of the First World War, and a further series of accounts followed the Second World War. More recently, MG has been deployed in warfare in the Middle East and this resulted in large numbers of victims, whose conditions have been studied in detail at hospitals in the region. In this review, we bring together the older and more recent clinical studies on MG toxicity and summarize what is now known about the acute and chronic effects of the agent on the eyes, skin, respiratory tract and other physiological systems. In the majority of patients, the most clinically serious long-term consequences of MG poisoning are on the respiratory system, but the effects on the skin and other systems also have a significant impact on quality of life. Aspects of the management of these patients are discussed.

Overexpression of transforming growth factor (TGF)-beta1 and TGF-beta3 genes in lung of toxic-inhaled patients

Iraq frequently used toxic inhalants during the war with Iran, exposing over 100,000 people to chemical reagents. Bronchiolitis obliterans (BO) is a major pulmonary disease caused by exposure to harmful gases. Recently defect in clearance of apoptotic cells (efferocytosis) has been suggested as a mechanism that leads to several lung diseases. Transforming growth factor (TGF)-beta, a cytokine produced by efferocytotic macrophages, suppresses the inflammation and enhances the regeneration of tissue. In this study, the authors compared the expression of these 3 isoforms of TGF-beta at mRNA level in lung biopsies of Iranian victims of chemical gases with lung biopsies of control healthy volunteers. Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) technique was used to examine the expression level of TGF-beta isoforms using glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene as an internal control. The results indicated that that levels of TGF-beta1 and TGF-beta3 mRNAs were significantly higher in chemical gas-injured patients than noninjured group (P < .05). Therefore, the authors speculate that TGF-beta1 and TGFbeta3, but not TGF-beta2, secretion is a result of efficient efferocytosis in chemically injured patients, playing a protective role by improving airway remodeling and lung homeostasis in this group. These properties of TGF-beta are consistent with long-time survival of chemical-injured people suffering from BO.

Detection and monitoring of early airway injury effects of half-mustard (2-chloroethylethylsulfide) exposure using high-resolution optical coherence tomography

Optical coherence tomography (OCT) is a noninvasive, high-resolution imaging technology capable of delivering real-time, near-histologic images of tissues. Mustard gas is a vesicant-blistering agent that can cause severe and lethal damage to airway and lungs. The ability to detect and assess airway injury in the clinical setting of mustard exposure is currently limited. The purpose of this study is to assess the ability to detect and monitor progression of half-mustard [2-chloroethylethylsulfide (CEES)] airway injuries with OCT techniques. A ventilated rabbit mustard exposure airway injury model is developed. A flexible fiber optic OCT probe is introduced into the distal trachea to image airway epithelium and mucosa in vivo. Progression of airway injury is observed over eight hours with OCT using a prototype time-domain superluminescent diode OCT system. OCT tracheal images from CEES exposed animals are compared to control rabbits for airway mucosal thickening and other changes. OCT detects the early occurrence and progression of dramatic changes in the experimental group after exposure to CEES. Histology and immunofluorescence staining confirms this finding. OCT has the potential to be a high resolution imaging modality capable of detecting, assessing, and monitoring treatment for airway injury following mustard vesicant agent exposures.

Late laryngeal findings in sulfur mustard poisoning

INTRODUCTION

Sulfur mustard is an alkylating warfare agent and its inhalation results in early and late toxic effects. This agent was used widely against both military and civilian population by Iraqi forces in the Iran-Iraq war (1983-88). The purpose of the study was to describe abnormal laryngeal findings in a group of chemical war injury patients (soldiers) 20 years after an acute exposure to sulfur mustard.

METHODS

In this observational case series study, 50 male patients who were suffering from chronic respiratory symptoms and because of exacerbation of these problems, were consecutively selected and clinically examined for dysphonia by a speech-language pathologist, and then underwent fiberoptic laryngobronchoscopy to describe anatomical and functional pathologic findings of the larynx.

RESULTS

In objective speech evaluation, different degrees of dysphonia including harshness and hoarseness were observed in 46% of patients. Inflammation was present in supraglottic and subglottic regions of 9 (18%) and 3 (6%) patients, respectively. Hyperfunction of the false vocal cords was observed in 24 (48%) patients.

CONCLUSION

Chronic laryngitis was seen in a considerable number of exposed victims nearly 20 years after exposure, in spite of different treatments received.

An international collaborative pathologic study of surgical lung biopsies from mustard gas-exposed patients

BACKGROUND

Recent studies have shown strong evidence that bronchiolitis obliterans is the major long-term sequelae of exposure to sulfur mustard (SM). This study is the first to examine the histopathologic spectrum of changes in a large number of surgical lung biopsies from patients exposed to SM.

METHOD

Fifteen patients with chronic respiratory disease from mustard gas exposure were divided into severe (6 cases) and mild exposure (9 cases). All had surgical (open or thoracoscopic) lung biopsy, pulmonary function tests (PFTs) and chest high-resolution computed tomography scan (HRCT).

RESULT

The mean age of the cases was 43.8+/-9.6 (range 33-65). All patients had dyspnea and cough as the two main complaints. Only one patient was a smoker. Thirteen patients had normal PFTs, while one had obstruction and one had mild restriction. Six (66.6%) patients in the mild exposure and 3 (50%) in the severe exposure group showed evidence of more than 25% air trapping on chest HRCT. Among the mild group, 3 had features of constrictive bronchiolitis and another had features suggestive of this (bronchiolectasis and mucus stasis). The next most common finding was a mild-to-moderate chronic cellular bronchiolitis (3 patients). Two among the 6 in the severe group showed constrictive bronchiolitis and one showed features suggestive of constrictive bronchiolitis.

CONCLUSION

We conclude that about half of patients had diagnostic constrictive bronchiolitis, or bronchiolectasis and mucus stasis consistent with more proximal luminal compromise. The fact that there were no differences between the low- and high-dose groups suggests that effects of SM are not solely dependent on the severity of exposure. The results also indicate that the diagnosis of chronic lung disease due to SM may be difficult. Surgical lung biopsy may be helpful in difficult cases, as constrictive (obliterative) bronchiolitis can be present in symptomatic patients with normal PFTs and chest HRCT.

Mustard Gas: Imminent Danger or Eminent Threat?

Objective:

To increase awareness of the widespread environmental prevalence of the chemical warfare agent mustard gas, examine the acute and chronic toxic effects to exposed humans, and discuss medical treatment guidelines for mustard gas exposures.

Data Sources:

Literature retrieval of medical case reports and clinical studies was accomplished using PubMed and the Cochrane Database (1919–March 2007). Search terms included mustard, mustard gas, sulfur mustard, chemical warfare, blister agents, vesicants, and war gas. Historical information and current events were accessed through military field manuals and Internet searches.

Study Selection and Data Extraction:

All articles in English identified from the data sources were evaluated. Adult and pediatric populations were included in the review.

Data Synthesis:

Mustard gas and other chemical weapons are feared for their use as weapons of terror; however, the major threat of mustard gas lies elsewhere. Tons of this chemical agent were produced for war, then subsequently buried in landfills, disposed of at sea, or teft to decay in storage lacrlities. There are documented and anecdotal reports of chemical weapon buriat sites and ocean dumps across the globe spanning from the Arctic Circle to Australia. Numerous accidental exposures have occurred over the past decade. Mustard gas is corrosive to the skin, eyes, and respiratory tract. Extensive exposures can also affect other organ systems. Its ability to cause harm to multiple organ systems at extremely low doses in virtually any environmental condition makes it an extremely dangerous agent. Immediate decontamination of people exposed to mustard gas liquids and vapors is paramount. Supportive care and long-term followup is necessary for exposed persons. Research is under way to find antidotes or treatment methods for mustard gas exposure, but currently there are no definitive treatment guidelines.

Conclusions:

Mustard gas is a weapon, but also a prevalent environmental threat. Recognizing the immense environmental presence of mustard gas disposal sites and the signs and symptoms of exposure will help speed treatment to those accidentally or purposefully exposed.

Longitudinal quantification of growth and changes in primary tracheobronchomalacia sites in children

RATIONALE

Longitudinal follow-up of children with tracheobronchomalacia is essential to improving our understanding of these disorders, yet currently, there is no such data.

OBJECTIVES

To longitudinally define malacia sites and quantify the cross-sectional area (CSA) of the lumen using a bronchoscopic technique and to relate these measurements to illness profiles.

METHODS

The validated color histogram mode technique was utilized to quantify primary malacia lesions and airway sites' CSA. Illness frequency, validated scales of illness and cough diary scores were prospectively used to assess clinical profiles.

RESULTS

Thirty-five malacia sites were defined from the 2 studies of 21 children. CSA of 21 (60%) of the malacia lesions increased, 5 (14%) new lesions appeared, 5 (14%) decreased in size, 3 (8%) remained unchanged, and 1(3%) was indeterminate. Overall there was no statistically significant change in paired-data assessments of malacia sites' area while there was a significant increase in area of non-malacia sites. The median yearly growth rate for the malacia sites and non-malacia was 3.65 mm2/year sites and 5.38 mm2/year, respectively (P = 0.31). The type and severity of lesion was not associated with any difference in growth rates, illness frequency or clinical scores.

CONCLUSIONS

Malacia lesions increase in size at the same rate as non-malacia sites. However malacia may worsen and new primary lesions may develop. Neither malacia type nor severity influences their growth pattern or illness profile.

Screening for peripheral neuropathy in chemical warfare victims

We aimed to assess the prevalence of peripheral neuropathy in chemical warfare victims. We speculated that peripheral neuropathy is a late complication of exposure to chemical warfare agents. Late complications of exposure to chemical warfare agents are not well known and are poorly discussed in the existing literature. Scientific data regarding delayed complications are sparse, but this warrants recognition, especially when the clinician has to treat chemical warfare victims. The hazards of organophosphate pesticides and several toxins, although recognized to some extent, are, however, different from the hazards of chemical warfare agents which are far more serious. In this study, 100 chemical warfare patients, with varying degrees of exposure and an average age of 37.2+/-9.0 years, were examined clinically and studied electrodiagnostically from January 2002 to January 2003. Five of these patients proved to be suffering from axonal neuropathy. This rate was significantly higher than that found in the normal population. Our data indicate that chemical warfare agents may cause peripheral neuropathy in chemical warfare victims. In conclusion, organophosphorous agents used against Iranian troops during the war on Iran correlate with delayed neuropathy in these victims.

Long term consequences from exposure to sulfur mustard: a review

Mustard gas (HD) was a widely used chemical warfare agent during World War I and more recently in the Iraq-Iran war (1980-1988). To date, dramatically, 45,000 Iranians are suffering from late respiratory complications due to MG exposure. This review covers two decades of researches on latent pulmonary effects of MG. Findings from clinical manifestations, pathologic examinations, laboratory data, lung function tests, and radiological evaluations are reviewed. From this review we are able to provide a suitable practical plan for workup and management of patients in this setting.

Mounier-Kuhn syndrome: a rare cause of severe bronchial dilatation with normal pulmonary function test: a case report

Tracheobronchomegaly (TBM) (Mounier-Kuhn syndrome) is dilatation of the trachea and major bronchi because of atrophy or absence of elastic fibers and smooth muscle cells. We present a case of TBM with normal pulmonary function test (PFT). The patient was a 37-year-old man with increasing productive cough and without fever, wheezes, chest pain, weight loss or any respiratory disease. Chest helical computed tomography (CT) scan showed tracheomegaly with transversal diameters of the trachea of 44mm. CT scan showed collapse of the trachea. Few large diverticular out-pouching and openings in the trachea was seen in bronchoscopy. PFT results were normal. PFT in large airway disorders may be normal while abnormalities may indicate underlying small airway disorder. An underlying small airway disorders is responsible for abnormal reports in PFT of these patients. We may need to re-evaluate the role of PFT within follow-up of patients with large airway disorder.