Smoking-related Interstitial Lung Diseases Research Articles

The providing multidisciplinary ILD diagnoses (PROMISE) study – study design of the national registry of Japan facilitating interactive online multidisciplinary discussion diagnosis

BackgroundMultidisciplinary discussion (MDD), in which physicians, radiologists, and pathologists communicate and diagnose together, has been reported to improve diagnostic accuracy compared to diagnoses made solely by physicians. However, even among experts, diagnostic concordance of MDD is not always good, and some patients may not receive a specific diagnosis due to insufficient findings. A provisional diagnosis based on the ontology with a diagnostic confidence level has recently been proposed. Additionally, we developed an artificial intelligence model to differentiate idiopathic pulmonary fibrosis (IPF) from other chronic interstitial lung diseases (ILD)s, which needs validation in a broader population.MethodsThis prospective nationwide ILD registry has recruited patients with newly diagnosed ILD at the referral respiratory hospitals in Japan and provides rapid MDD diagnoses and treatment recommendations through a central online MDD platform with a 3-year follow-up period. A modified diagnostic ontology is used. If no diagnosis reaches more than 50% certainty, the diagnosis is unclassifiable ILD. If multiple diseases are expected, the diagnosis with a high probability takes precedence. If the confidence levels for the top two possible diagnoses are equal, the diagnosis can be unclassifiable. The registry uses tentative diagnostic criteria for nonspecific interstitial pneumonia with organising pneumonia and smoking-related ILD not otherwise specified as possible new entities. Central MDD diagnosticians review the clinical data, test results, radiology images, and pathological specimens on a dedicated website and conduct MDD diagnoses using online meetings with a cloud-based reporting system. This study aims to (1) provide MDD diagnoses with treatment recommendations; (2) determine the overall ILD rates in Japan; (3) clarify the reasons for unclassifiable ILDs; (4) evaluate possible new disease entities; (5) identify progressive phenotypes and create a clinical prediction model; (6) measure the agreement rate between institutional and central diagnoses in ILD referral and non-referral centres; (7) identify key factors for each specific ILD diagnosis; and (8) create a new disease classification system based on treatment strategies, including the use of antifibrotic drugs.DiscussionThis study will provide ILD frequencies, including new entities, using central MDD on dedicated online systems, and develop a machine learning model for ILD diagnosis and prognosis prediction.Trial registrationUMIN-CTR Clinical Trial Registry (UMIN000040678).

Smoking-related interstitial lung disease : Radiological findings, histopathological correlations, and clinical observations

Identifying smoking-related interstitial lung diseases (SRILD) in smokers is challenging, as clinical manifestations can be nonspecific, and there is avariety of SRILD entities that not only interconnect but can also overlap. In diagnosing SRILD, imaging techniques such as high-resolution computed tomography (HRCT) allow the identification of characteristic features, serving as crucial pieces of the puzzle for definitive differentiation. Studies have demonstrated that HRCT exhibits asensitivity of approximately 80-90% in identifying SRILD, with aspecificity around 70-80%. The conclusive diagnosis often requires acorrelation between histopathological findings and clinical observations. Regular monitoring of smokers, especially when experiencing symptoms like shortness of breath and cough, coupled with acomprehensive diagnosis of SRILD, is crucial for accurate identification and individualized therapy.

Smoking-Related Interstitial Fibrosis and Smoker's Macrophages.

Smoking-related interstitial lung diseases (SRILDs) are a group of heterogeneous diffuse pulmonary parenchymal diseases associated with tobacco exposure. Smoking-related interstitial fibrosis (SRIF) is relatively recent, a pathologically defined form of SRILDs. SRIF is characterized by the accumulation of macrophages in the alveolar spaces, which is associated with interstitial inflammation and fibrosis. The macrophages frequently contain light brown pigment and are called 'smoker's macrophages'. Patients with SRIF who have clinical evidence of interstitial lung disease are most commonly relatively young, heavy smokers with abnormalities on chest computed tomography showing ground-glass opacities, peripheral consolidation, and reticulation. Although SRIF is caused by cigarette smoking, the exact pathophysiological mechanisms by which smoking causes this type of interstitial fibrosis remain unknown. The degree of fibrosis and appearance of macrophage aggregates are important points of distinction when evaluating and diagnosing SRIF. Macrophage heterogeneity, particularly the activation and function of monocyte-derived alveolar macrophages (Mo-AMs) and interstitial macrophages (IMs), has important implications for the pathogenesis of SRIF and developing treatments. Further researches focused on smoker's macrophages are needed to understand of the pathogenesis of SRIF.

Smoking-related interstitial lung disease: A narrative review.

Although smoking-related interstitial lung diseases (SR-ILD) are a relatively rare group of entities, they are a relevant public health problem of growing importance, both because they affect young adults and because of their increasing prevalence in recent years due to increased tobacco consumption. In patients who smoke and have non-specific respiratory symptoms, SR-ILD should be ruled out, a term that encompasses a group of different entities in which the basis for diagnosis is the smoking history together with compatible respiratory functional findings, radiology and/or histology. An association has been established between tobacco smoke and a group of diseases that include respiratory bronchiolitis-associated interstitial lung disease (2%-3% of all ILD), desquamative interstitial pneumonia (<1%), Langerhans cell histiocytosis (3%-5%) and acute eosinophilic pneumonia. Smoking is considered a risk factor for idiopathic pulmonary fibrosis which has also been called combined fibroemphysema (5%-10% of all ILD); however, the role and impact of smoking in its development, remains to be determined. The likely interconnection between the mechanisms involved in inflammation and pulmonary fibrosis in all these processes often results in an overlapping of clinical, radiological, and histological features. In the absence of robust scientific evidence on its management, smoking cessation is the first measure to be taken into account. Although most diseases have a benign clinical course after smoking cessation, some cases may progress to chronic respiratory failure.

Bronchoalveolar cytokine profile differentiates Pulmonary Langerhans cell histiocytosis patients from other smoking-related interstitial lung diseases

BackgroundPulmonary Langerhans cell histiocytosis (PLCH) is a rare interstitial lung disease (ILD) associated with smoking, whose definitive diagnosis requires the exclusion of other forms of ILD and a compatible surgical lung biopsy. Bronchoalveolar lavage (BAL) is commonly proposed for the diagnosis of ILD, including PLCH, but the diagnostic value of this technique is limited. Here, we have analyzed the levels of a panel of cytokines and chemokines in BAL from PLCH patients, in order to identify a distinct immune profile to discriminate PLCH from other smoking related-ILD (SR-ILD), and comparing the results with idiopathic pulmonary fibrosis (IPF) as another disease in which smoking is considered a risk factor.MethodsBAL samples were collected from thirty-six patients with different ILD, including seven patients with PLCH, sixteen with SR-ILD and thirteen with IPF. Inflammatory profiles were analyzed using the Human Cytokine Membrane Antibody Array. Principal component analysis (PCA) was performed to reduce dimensionality and protein–protein interaction (PPI) network analysis using STRING 11.5 database were conducted. Finally, Random forest (RF) method was used to build a prediction model.ResultsWe have found significant differences (p < 0.05) on thirty-two cytokines/chemokines when comparing BAL from PLCH patients with at least one of the other ILD. Four main groups of similarly regulated cytokines were established, identifying distinct sets of markers for each cluster. Exploratory analysis using PCA (principal component analysis) showed clustering and separation of patients, with the two first components capturing 69.69% of the total variance. Levels of TARC/CCL17, leptin, oncostatin M (OSM) and IP-10/CXCL10 were associated with lung function parameters, showing positive correlation with FVC. Finally, random forest (RF) algorithm demonstrates that PLCH patients can be differentiated from the other ILDs based solely on inflammatory profile (accuracy 96.25%).ConclusionsOur results show that patients with PLCH exhibit a distinct BAL immune profile to SR-ILD and IPF. PCA analysis and RF model identify a specific immune profile useful for discriminating PLCH.

Smoking-related interstitial lung disease

Exposure to smoke is associated with the development of diseases of the airways and lung parenchyma. Apart from chronic obstructive pulmonary disease (COPD), in some individuals, tobacco smoke can also trigger mechanisms of interstitial damage that result in various pathological changes and pulmonary fibrosis. A causal relation has been established between tobacco smoke and a group of entities that includes respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), desquamative interstitial pneumonia (DIP), Langerhans cell histiocytosis (LCH), and acute eosinophilic pneumonia (AEP). Smoking is considered a risk factor for idiopathic pulmonary fibrosis (IPF); however, the role and impact of smoking in the development of this differentiated clinical entity, which has also been called combined pulmonary fibrosis and emphysema (CPFE) as well as nonspecific interstitial pneumonia (NIP), remains to be determined. The definition of smoking-related interstitial fibrosis (SRIF) is relatively recent, with differentiated histological characteristics. The likely interconnection between the mechanisms involved in inflammation and pulmonary fibrosis in all these processes often results in an overlapping of clinical, radiological, and histological features in the same patient that can sometimes lead to radiological patterns of interstitial lung disease that are impossible to classify. For this reason, a combined approach to diagnosis is recommendable. This combined approach should be based on the joint interpretation of the histological and radiological findings while taking the clinical context into consideration. This paper aims to describe the high-resolution computed tomography (HRCT) findings in this group of disease entities in correlation with the clinical manifestations and histological changes underlying the radiological pattern.

Transbronchial Lung Cryobiopsy for Diagnosing Interstitial Lung Disease: A Retrospective Single-Center Experience.

Background An accurate diagnosis in patients with interstitial lung diseases (ILDs) by multidisciplinary discussion (MDD) based on histopathologic information is essential for optimal treatment. Transbronchial lung cryobiopsy (TBLC) has increasingly been used as a diagnostic alternative to surgical lung biopsy. This study aimed to evaluate the appropriate methods of TBLC in patients with ILD in Korea.Methods A total of 27 patients who underwent TBLC were included. TBLC procedure details and clinical MDD diagnosis using TBLC histopathologic information were retrospectively analyzed.Results All procedures were performed under general anesthesia with the fluoroscopic guidance in the operation room using flexible bronchoscopy and endobronchial balloon blocker. The median procedure duration was less than 30 minutes, and the median number of biopsies per participant was 2. Most of the bleeding after TBLC was not severe, and the rate of pneumothorax was 25.9%. The most common histopathologic pattern was alternative (48.2%), followed by indeterminate (33.3%) and usual interstitial pneumonia (UIP)/probable UIP (18.5%). In the MDD after TBLC, the most common diagnosis was idiopathic pulmonary fibrosis (33.3%), followed by smoking-related ILD (25.9%), nonspecific interstitial pneumonia (18.6%), unclassifiable-ILD (14.8%), and others (7.4%).Conclusion This first single-center experience showed that TBLC using a flexible bronchoscopy and endobronchial balloon blocker with the fluoroscopic guidance under general anesthesia may be a safe and adequate diagnostic method for ILD patients in Korea. The diagnostic yield of MDD was 85.2%. Further studies are needed to evaluate the diagnostic yield and confidence of TBLC.

Environmental and occupational exposures in interstitial lung disease.

We highlight recent advances in the understanding of how environmental and occupational exposures increase the risk of developing interstitial lung disease (ILD), and how to evaluate a patient for potential exposures. A review of emerging literature suggests that environmental and occupational exposures can be directly causal, as in the case of the pneumoconioses and smoking-related ILDs, or one of many contributors to disease, as in the case of idiopathic pulmonary fibrosis (IPF). Regardless of the level of association, exposures are clearly prevalent across all ILD subtypes studied. Inhalational exposures are increasingly recognized as an important component in the development of ILDs, and novel exposure-disease associations continue to be discovered. These exposures represent potential opportunities for further understanding the pathobiology of disease and for the prevention of these often progressive and debilitating disorders. Prospective, comprehensive data collection regarding occupational and environmental exposures are needed in ILD patients to fully elucidate specific antigens and their relationships to disease incidence and outcomes. Systematically collected exposure information will also inform potential interventions to remediate exposures and thus mitigate the course of frequently progressive and fatal diseases.

Smoking-related interstitial lung diseases

Klinisches ProblemRaucherassoziierte interstitielle Lungenerkrankungen umfassen heterogene pulmonale Pathologien, deren korrekte Diagnostik prognostische und therapeutische Konsequenzen hat. In diesem Artikel werden die gängigsten raucherassoziierten interstitiellen Lungenerkrankungen beschrieben sowie eine strukturierte Herangehensweise präsentiert, welche den diagnostischen Arbeitsprozess erleichtern kann.Empfehlungen für die PraxisDie Computertomographie (CT) besitzt einen hohen Stellenwert in der Diagnose der raucherassoziierten interstitiellen Lungenerkrankungen und kann dazu beitragen, Lungenbiopsien zu verhindern. Um eine hohe diagnostische Genauigkeit zu erreichen, sollten standardisierte Untersuchungsprotokolle sowie eine strukturierte Herangehensweise in der Befundung zur Anwendung kommen. In den entzündlich dominierten Stadien der respiratorischen Bronchiolitis (RB), der respiratorischen Bronchiolitis mit interstitieller Lungenerkrankung (RB-ILD) sowie der desquamativen interstitiellen Pneumonie (DIP) haben die Beendigung des Rauchens sowie Steroide den größten therapeutischen Effekt. Bei fibrotischen Veränderungen (z. B. im Rahmen einer idiopathischen pulmonalen Fibrose [IPF]) können antifibrotische Therapien mit Pirfenidon und Nintedanib zum Einsatz kommen. Patienten mit dem Verdacht auf raucherassoziierte interstitielle Lungenerkrankung sollten in multidisziplinären Boards abgeklärt und behandelt werden.

Incidental findings on lung cancer screening: pictorial essay and systematic checklist

ABSTRACTLung cancer screening (LCS) programs are increasing worldwide. Incidental findings (IFs) on LCS are defined as low-dose CT findings unrelated to the primary purpose of identifying lung cancer. Most IFs on LCS are benign and clinically insignificant but are being increasingly recognized, and some require urgent referral for further diagnostic workup. Other findings are expected and are known as smoking-related comorbidities, including COPD, cardiovascular disease, emphysema, and interstitial lung disease, and their diagnosis can have a significant impact on patient prognosis. The purpose of this pictorial essay is to illustrate the most common IFs on LCS, organized by organ. We will discuss the current literature on IFs on LCS, focusing on their prevalence, appropriate communication, and triggering of clinical pathway systems.

Atypical case of pulmonary Langerhans cell histiocytosis presenting as miliary nodules

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare smoking-related interstitial lung disease affecting primarily young adult smokers. Diagnosis is made with typical radiographic findings of centrilobular nodules and cystic lesions on high resolution computed tomography (HRCT) confirmed with tissue biopsy. We describe a case of a 59-year-old man presenting with chronic tobacco use and cough who was found to have an atypical radiographic finding of miliary nodules on HRCT that was confirmed as PLCH on transbronchial lung biopsy.

Clinical Features and Outcomes of Combined Pulmonary Fibrosis and Emphysema After Lung Transplantation

Combined pulmonary fibrosis and emphysema (CPFE) is recognized as a characteristic syndrome of smoking-related interstitial lung disease that has a worse prognosis than idiopathic pulmonary fibrosis (IPF). However, outcomes after lung transplantation for CPFE have not been reported. The aim of this study is to describe the clinical features and outcomes of CPFE after lung transplantation. What are the clinical features and outcomes of CPFE after lung transplantation? This is a single-center retrospective cohort study of patients with CPFE and IPF who underwent lung transplantation at our center between January 2011 and December 2016. We defined CPFE as≥10%emphysema in the upper lung fields combined with fibrosis on high-resolution CT scan. We characterized the clinical features of patients with CPFE and compared their outcomes after lung transplantation with those with IPF. Twenty-seven of 172 (16%) patients with IPF met criteria for CPFE. Severe pulmonary hypertension was present in 16 of 27 (59%) patients with CPFE. On logistic regression analysis, CPFE was significantly associated with primary graft dysfunction (PGD) grade 3 (OR, 3.14; 95%CI, 1.18-8.37; P= .02). On competing risk regression analysis, CPFE was associated with acute cellular rejection (ACR) grade≥ A2, and chronic lung allograft dysfunction (CLAD) (hazard ratio [HR], 1.89; 95%CI, 1.10-3.25; P= .02; HR, 1.96; 95%CI, 1.02-3.77; P= .04, respectively). Five-year survival was 79.0%for the CPFE group and 75.4%for the IPF group (log-rank P= .684). After transplantation, patients with CPFE were more likely to develop PGD, ACR, and CLAD compared with those with IPF. However, survival was not significantly different between the two groups.

A comprehensive assessment of environmental exposures and the medical history guides multidisciplinary discussion in interstitial lung disease.

Multidisciplinary discussion (MDD) is widely recommended for patients with interstitial lung disease (ILD), but published primary data from MDD has been scarce, and factors influencing MDD other than chest computed tomography (CT) and lung histopathology interpretations have not been well-described. Single institution MDD of 179 patients with ILD. MDD consensus clinical diagnoses included autoimmune-related ILD, chronic hypersensitivity pneumonitis, smoking-related ILD, idiopathic pulmonary fibrosis, medication-induced ILD, occupation-related ILD, unclassifiable ILD, and a few less common pulmonary disorders. In 168 of 179 patients, one or more environmental exposures or pertinent features of the medical history were identified, including recreational/avocational, residential, and occupational exposures, systemic autoimmune disease, malignancy, medication use, and family history. The MDD process demonstrated the importance of comprehensively assessing these exposures and features, beyond merely noting their presence, for rendering consensus clinical diagnoses. Precise, well-defined chest CT and lung histopathology interpretations were rendered at MDD, including usual interstitial pneumonia, nonspecific interstitial pneumonia, and organizing pneumonia, but these interpretations were associated with a variety of MDD consensus clinical diagnoses, demonstrating their nonspecific nature in many instances. In 77 patients in which MDD consensus diagnosis differed from referring diagnosis, assessment of environmental exposures and medical history was found retrospectively to be the most impactful factor. A comprehensive assessment of environmental exposures and pertinent features of the medical history guided MDD. In addition to rendering consensus clinical diagnoses, MDD presented clinicians with opportunities to initiate environmental remediation, behavior modification, or medication alteration likely to benefit individual patients with ILD.

English

BACKGROUND Diffuse interstitial lung disease is on the rise in recent times. This could be attributed to number of causes / reasons. Environmental pollution is one of the important causes for the upswing. Increased exposure to inorganic dust, toxic fumes, certain drugs (gold, amiodarone, antibiotics etc.) and radiation can also cause ILD (Interstitial Lung Disease). METHODS This is a hospital based prospective observational study, conducted in the Department of Radiodiagnosis, NSCB Medical College and Hospital, Jabalpur. This study comprised of a total of 50 patients clinically diagnosed interstitial lung disease who had undergone x-ray chest and HRCT (High-Resolution Computed Tomography) Chest examination. RESULTS Incidence of interstitial lung disease was maximum in the middle age group of 51 – 60 years (38 %) with male predominance (58 %). Smoking habit was seen to be associated with 52 % of the cases suggesting association. 8 patients (16 %) had developed diffuse lung disease secondary to connective tissue disorder (rheumatoid arthritis, progressive systemic sclerosis and polymyositis). A confident diagnosis was made on the basis of chest radiograph alone in 11 patients (29 %). Among cases evaluated by HRCT Chest, 41 (82 %) cases showed specific patterns of ILD and nine cases (18 %) showed nonspecific patterns and were classified under unclassified IIP (Idiopathic Interstitial Pneumonia). Out of 41 cases, the most common ILD reported was IPF (20) followed by cases of idiopathic NSI, 8 cases of collagen vascular diseases, 2 cases suggestive of COP / BOOP, and smoking related ILDs were seen in 4 cases, and 2 cases of sarcoidosis were seen in the study. Occupational- and radiation-induced-ILD were seen in one case each. CONCLUSIONS Chest radiography is the initial imaging investigation in the evaluation of diffuse interstitial lung disease. HRCT is the imaging modality of choice to assess interstitial lung disease. It can detect lesion even when the chest radiograph is normal. HRCT can confirm the location, extent of disease, and pattern of disease. HRCT helps in the confident diagnosis of ILD as compared to chest radiography. Thus, it avoids lung biopsy in a large number of patients. HRCT is also useful in assessing the disease reversibility. Follow up of patients is better done by HRCT. KEYWORDS HRCT, Interstitial Lung Disease, Chest X-Ray, Ground Glass Opacity, Honeycombing

RESTRICTIVE HUT LUNG: A CASE OF DOMESTICALLY-ACQUIRED PNEUMOCONIOSIS WITH A SEVERE RESTRICTIVE PATTERN

SESSION TITLE: Medical Student/Resident Occupational and Environmental Lung Disease SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Domestically acquired particulate lung disease (DAPLD) or “hut lung” is a mixed-dust pneumoconiosis that develops secondary to the inhalation of biomass fuels in poorly ventilated domestic settings (1). DAPLD has largely been considered to be an obstructive lung disease, with only a minority of cases reporting mild restrictive or mixed patterns of disease (1). To our knowledge, this is the first case report of DAPLD with a severe restrictive pattern. CASE PRESENTATION: A 76 year old Hispanic woman presented with worsening shortness of breath for one year, associated with reduced exercise tolerance, nonproductive cough, chest tightness, and wheezing. She spends majority of the year in Honduras, but travels to the United States for the summer months. She denied smoking tobacco and occupational exposures, but admitted to using a wood burning stove for cooking while living in Honduras for many years. CXR was notable for bilateral patchy infiltrates. HRCT showed large patchy and confluent areas of ground glass attenuation in association with linear and reticular opacities, and peripheral honeycombing with cystic changes. Small calcified bilateral hilar lymph nodes were also observed. Quantiferon testing was positive, but serial cultures were negative for tuberculosis. PFTs showed a restrictive pattern: FEV1 82%, FVC 59%, FEV1/FVC 95%, TLC 46%, DLCO 7%. Bronchoscopy showed multiple flat anthracotic plaques; transbronchial biopsy of these lesions demonstrated focal chronic inflammation. BAL cytology and cultures were unremarkable. DISCUSSION: Although the prevalence of DAPLD is unknown, inhalation of particulate residue of biomass fuels used for domestic energy is common in several parts of the world (2). Cooking with biomass fuels may be associated with fine particle carbon dispersion (2). Deposition of biomass fine particles along alveolar surfaces and macrophage activation initiates an inflammatory response (2). Discourse on biomass inhalation and tobacco smoking has focused on the development of COPD, however both of these exposures may also result in ILD (3). Type 2 alveolar epithelial stem cells, which may function as both type I and type II alveolar cells, have been proposed to play a central role in predisposing patients with tobacco and biomass exposure, to both COPD and ILD phenotypes (2,3). Tobacco and biomass have been proposed to induce cellular senescence, which allows for genetic remodeling and profibrotic cellular changes (2,3). Predisposition of these stem cells to senescence would make certain patients susceptible to COPD or ILD based on the chosen behavior of the stem cell (3). CONCLUSIONS: While the body of research on the hazards of exposure to biomass continues to grow, the restrictive phenotype of DAPLD remains a rare condition that requires further research. Reference #1: Dulku, G, Gupta, N, Perera, R, et al. 2017. Hut Lung Disease: A Radiological and Pathological Correlation. J Med Imaging Case Rep 1(1): 1-4. Reference #2: Kunal S, Pilaniya V, Shah A. 2016. Bronchial Anthracofibrosis with Interstitial Lung Disease: An Association Yet to be Highlighted. BMJ Case Rep bcr2015213940. Reference #3: Kumar, A, Cherian, SV, Vassallo, R, et al. 2018. Current Concepts in Pathogenesis, Diagnosis, and Management of Smoking-Related Interstitial Lung Diseases. Chest 154(2): 394-408. DISCLOSURES: No relevant relationships by Rose Flores, source=Web Response No relevant relationships by Johnathan Kirupakaran, source=Web Response No relevant relationships by Chioma Madu, source=Web Response No relevant relationships by Alice Yau, source=Web Response

Five simple reasons to discard DIP, or why we should stop calling dolphins big fish

The aim of this review is to explain why the term ‘desquamative interstitial pneumonia’ (DIP) should be discarded and replaced with modern terminology. Reason 1: DIP is a misnomer. Within...

Cryobiopsy in the diagnosis of bronchiolitis: a retrospective analysis of twenty-three consecutive patients

Bronchiolitis manifests as a variety of histological features that explain the complex clinical profiles and imaging aspects. In the period between January 2011 and June 2015, patients with a cryobiopsy diagnosis of bronchiolitis were retrospectively retrieved from the database of our institution. Clinical profiles, imaging features and histologic diagnoses were analysed to identify the role of cryobiopsy in the diagnostic process. Twenty-three patients with a multidisciplinary diagnosis of small airway disease were retrieved (14 females, 9 males; age range 31–74 years old; mean age 54.2 years old). The final MDT diagnoses were post-infectious bronchiolitis (n = 5), constrictive bronchiolitis (n = 3), DIPNECH (n = 1), idiopathic follicular bronchiolitis (n = 3), Sjogren’s disease (n = 1), GLILD (n = 1), smoking-related interstitial lung disease (n = 6), sarcoid with granulomatous bronchiolar disorder (n = 1), and subacute hypersensitivity pneumonitis (n = 2). Complications reported after the cryobiopsy procedure consisted of two cases of pneumothorax soon after the biopsy (8.7%), which were successfully managed with the insertion of a chest tube. Transbronchial cryobiopsy represents a robust and mini-invasive method in the characterization of small airway diseases, allowing a low percentage of complications and good diagnostic confidence.

WHERE DID THE HISTIOCYTES COME FROM? A CASE OF DIFFUSE LUNG INFILTRATES WITH HISTIOCYTOSIS IN BRONCHOALVEOLAR LAVAGE

SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Analyzing bronchoalveolar lavage (BAL) fluid provides useful information for diffuse bilateral pulmonary infiltrates with unclear etiologies. We report a case of bilateral interstitial lung disease with histiocytes predominant in BAL in an otherwise healthy female. CASE PRESENTATION: 59 y/o female, never smoked, with no significant past medical history who presented with persistent cough of 2 months. She denied weight loss, night sweats, fever, chills, chest pain, shortness of breath, sick contacts, travel. Physical exam is unremarkable. Initial labs showed neutrophilic predominant leukocytosis. Chest x-ray showed patchy right lower lobe infiltrates. CT chest revealed diffuse bilateral pulmonary parenchymal abnormalities and mildly enlarged right paratracheal and right hilar lymph nodes. The patient underwent bronchoscopy and bronchoalveolar lavage (BAL), cultures grew alpha strep and Capnocytophaga species, BAL cytology revealed mainly histiocytes( 98%). Further testing negative for: influenza, tuberculosis, fungal panel, urine Legionella. Positive for Mycoplasma antibody IgG. She was treated for community acquired pneumonia with ceftriaxone and azithromycin with good clinical response. Patient had a repeat chest x-ray 2 weeks later which showed resolution of her right sided infiltrates, and blood work revealing restoration of leukocytosis. She reported improvement of her symptoms. All of these indicating resolution of her right sided pneumonia. DISCUSSION: Histiocytes are part of the mononuclear phagocyte system aka the reticuloendothelial system. In normal circumstances, histiocytes are mainly found as pulmonary alveolar macrophages. However, they actively participate in all inflammatory reactions of the lung. In some cases, risks factors like smoking could predispose patients to a specific histiocytic predominant pathology. Histiocytic pulmonary lesions present as nodular and/or diffuse proliferations in the lung. Pulmonary lesions with histiocytes predominant can be neoplastic, for example- histiocytic sarcoma; or non-neoplastic such as pulmonary Langerhans’ cell histiocytosis, desquamative interstitial pneumonia, pneumoconiosis, infections, diffuse panbronchiolitis, crystal storing histiocytosis, respiratory bronchiolitis, alveolar hemorrhage, eosinophilic pneumonia, obstructive pneumonia, exogenous lipoid pneumonia, some drug reactions, and other metabolic/storage disorders. Our patient presented with atypical pneumonia, cough for 2 months, diffuse interstitial infiltrates with histiocytosis in BAL. IgM for Mycoplasma pneumoniae negative, IgG with high titer. She had good clinical and radiological response with conservative management. CONCLUSIONS: In our case, Mycoplasma pneumoniae was etiology. Multidisciplinary approach and mechanism-based therapeutic strategies are important for diffuse interstitial lung disease with histiocytosis in BAL. Reference #1: Wang, C. and Colby, T. (2007). Histiocytic lesions and proliferations in the lung. Seminars in Diagnostic Pathology, [online] 24(3), pp.162-182. Available at: https://www.ncbi.nlm.nih.gov/pubmed/17882900. Reference #2: Andrea Morelli et al. Effect of Heart Rate Control With Esmolol on Hemodynamic and Clinical Outcomes in Patients With Septic Shock: A Randomized Clinical Trial. JAMA.2013;310(16):1683-1691. https://doi.org/10.1001/jama.2013.278477. Reference #3: Moon J, du Bois RM, Colby TV, et al. Clinical significance of respiratory bronchiolitis on open lung biopsy and its relationship to smoking related interstitial lung disease. Thorax 1999; 54:1009. DISCLOSURES: No relevant relationships by Violeta Alvarez-Retamales, source=Web Response No relevant relationships by Phyo Kyaw, source=Web Response

Interstitial Lung Diseases in Developing Countries.

More than 100 different conditions are grouped under the term interstitial lung disease (ILD). A diagnosis of an ILD primarily relies on a combination of clinical, radiological, and pathological criteria, which should be evaluated by a multidisciplinary team of specialists. Multiple factors, such as environmental and occupational exposures, infections, drugs, radiation, and genetic predisposition have been implicated in the pathogenesis of these conditions. Asbestosis and other pneumoconiosis, hypersensitivity pneumonitis (HP), chronic beryllium disease, and smoking-related ILD are specifically linked to inhalational exposure of environmental agents. The recent Global Burden of Disease Study reported that ILD rank 40th in relation to global years of life lost in 2013, which represents an increase of 86% compared to 1990. Idiopathic pulmonary fibrosis (IPF) is the prototype of fibrotic ILD. A recent study from the United States reported that the incidence and prevalence of IPF are 14.6 per 100,000 person-years and 58.7 per 100,000 persons, respectively. These data suggests that, in large populated areas such as Brazil, Russia, India, and China (the BRIC region), there may be approximately 2 million people living with IPF. However, studies from South America found much lower rates (0.4–1.2 cases per 100,000 per year). Limited access to high-resolution computed tomography and spirometry or to multidisciplinary teams for accurate diagnosis and optimal treatment are common challenges to the management of ILD in developing countries.

Smoking-related lung abnormalities on computed tomography images: comparison with pathological findings.

Smoking-related lung abnormalities are now an increasing public health concern. According to the findings of large-cohort studies, approximately 8% of smokers have interstitial lung abnormalities, which are associated with a relatively high risk of all-cause mortality. We reviewed the radiological and pathological findings of smoking-related interstitial lung diseases, such as respiratory bronchiolitis-interstitial lung disease, desquamative interstitial pneumonia, and airspace enlargement with fibrosis. We have also discussed the histological basis of unclassifiable interstitial pneumonia in smokers, which exhibits airway-centered cystic lesions with fibrosis. A variety of radiological findings coexist in the lungs of a smoker. This overlapping of multiple pathological conditions might cause the radiological patterns of diseases to become unclassifiable. Therefore, diagnosis should be performed not on the basis of a single radiological finding, but in a comprehensive manner, by including clinical symptoms and disease behavior. Among interstitial abnormalities in smokers, the usual interstitial pneumonia (UIP) pattern is correlated with a worse prognosis than others. Basal-predominant subpleural reticulation is a clue for accurate diagnosis of UIP, which can be achieved by computer-aided quantitative analysis.