Predictive value of BAL cell differentials in the diagnosis of interstitial lung diseases

[Diagnosis and Treatment of Hypersensitivity Pneumonitis - S2k Guideline of the German Respiratory Society and the German Society for Allergology and Clinical Immunology]

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) in sensitized individuals caused by a large variety of inhaled antigens. The clinical form of acute HP is often misdiagnosed, while the chronic form, especially the chronic fibrotic HP, is difficult to differentiate from other fibrotic ILDs. The present guideline for the diagnosis and treatment of HP replaces the former German recommendations for the diagnosis of HP from 2007 and is amended explicitly by the issue of the chronic fibrotic form, as well as by treatment recommendations for the first time. The evidence was discussed by a multidisciplinary committee of experts. Then, recommendations were formulated for twelve questions on important issues of diagnosis and treatment strategies. Recently published national and international guidelines for ILDs and HP were considered. Detailed background information on HP is useful for a deeper insight into HP and the handling of the guideline.

Multidisciplinary Approach to the Diagnosis of Idiopathic Interstitial Pneumonias: Focus on the Pathologist's Key Role

Idiopathic Interstitial Pneumonias (IIPs) are a heterogeneous group of the broader category of Interstitial Lung Diseases (ILDs), pathologically characterized by the distortion of lung parenchyma by interstitial inflammation and/or fibrosis. The American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary consensus classification of the IIPs was published in 2002 and then updated in 2013, with the authors emphasizing the need for a multidisciplinary approach to the diagnosis of IIPs. The histological evaluation of IIPs is challenging, and different types of IIPs are classically associated with specific histopathological patterns. However, morphological overlaps can be observed, and the same histopathological features can be seen in totally different clinical settings. Therefore, the pathologist's aim is to recognize the pathologic-morphologic pattern of disease in this clinical setting, and only after multi-disciplinary evaluation, if there is concordance between clinical and radiological findings, a definitive diagnosis of specific IIP can be established, allowing the optimal clinical-therapeutic management of the patient.

Combination of BAL and Computed Tomography Differentiates Progressive and Non-progressive Fibrotic Lung Diseases

Rationale: Identifying patients with pulmonary fibrosis (PF) at risk of progression can guide management. Objectives: To explore the utility of combining baseline BAL and computed tomography (CT) in differentiating progressive and nonprogressive PF. Methods: The derivation cohort consisted of incident cases of PF for which BAL was performed as part of a diagnostic workup. A validation cohort was prospectively recruited with identical inclusion criteria. Baseline thoracic CT scans were scored for the extent of fibrosis and usual interstitial pneumonia (UIP) pattern. The BAL lymphocyte proportion was recorded. Annualized FVC decrease of >10% or death within 1 year was used to define disease progression. Multivariable logistic regression identified the determinants of the outcome. The optimum binary thresholds (maximal Wilcoxon rank statistic) at which the extent of fibrosis on CT and the BAL lymphocyte proportion could distinguish disease progression were identified. Measurements and Main Results: BAL lymphocyte proportion, UIP pattern, and fibrosis extent were significantly and independently associated with disease progression in the derivation cohort (n = 240). Binary thresholds for increased BAL lymphocyte proportion and extensive fibrosis were identified as 25% and 20%, respectively. An increased BAL lymphocyte proportion was rare in patients with a UIP pattern (8 of 135; 5.9%) or with extensive fibrosis (7 of 144; 4.9%). In the validation cohort (n = 290), an increased BAL lymphocyte proportion was associated with a significantly lower probability of disease progression in patients with nonextensive fibrosis or a non-UIP pattern. Conclusions: BAL lymphocytosis is rare in patients with extensive fibrosis or a UIP pattern on CT. In patients without a UIP pattern or with limited fibrosis, a BAL lymphocyte proportion of ⩾25% was associated with a lower likelihood of progression.

Single-Cell Profiling of Cells in the Lung of a Patient with Chronic Hypersensitivity Pneumonitis Reveals Inflammatory Niche with Abundant CD39+ T Cells with Functional ATPase Phenotype: A Case Study

This study investigated immune cell characteristics in chronic hypersensitivity pneumonitis (HP), focusing on CD39-expressing cells' impact on inflammation and tissue remodelling. Lung tissue from an HP patient was analysed using single-cell transcriptomics, flow cytometry, and gene expression profiling. The tissue revealed diverse cell types like macrophages, T cells, fibroblasts, and regulatory T cells (Tregs). CD39-expressing Tregs exhibited heightened ATP hydrolysis capacity and regulatory gene expression. CD39hi cells displayed markers of both Tregs and proinflammatory Th17 cells, suggesting transitional properties. Communication networks involving molecules like SPP1, collagen, CSF1, and IL-1β were identified, hinting at interactions between cell types in HP pathogenesis. This research provides insights into the immune response and cell interactions in chronic HP. CD39-expressing cells dual nature as Tregs and Th17 cells suggests a role in modulating lung inflammation, potentially affecting disease progression. These findings lay the groundwork for further research, underscoring CD39-expressing cells as potential therapeutic targets in HP.

Differential diagnosis of pulmonary sarcoidosis: a review

Diagnosing pulmonary sarcoidosis raises challenges due to both the absence of a specific diagnostic criterion and the varied presentations capable of mimicking many other conditions. The aim of this review is to help non-sarcoidosis experts establish optimal differential-diagnosis strategies tailored to each situation. Alternative granulomatous diseases that must be ruled out include infections (notably tuberculosis, nontuberculous mycobacterial infections, and histoplasmosis), chronic beryllium disease, hypersensitivity pneumonitis, granulomatous talcosis, drug-induced granulomatosis (notably due to TNF-a antagonists, immune checkpoint inhibitors, targeted therapies, and interferons), immune deficiencies, genetic disorders (Blau syndrome), Crohn's disease, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and malignancy-associated granulomatosis. Ruling out lymphoproliferative disorders may also be very challenging before obtaining typical biopsy specimen. The first step is an assessment of epidemiological factors, notably the incidence of sarcoidosis and of alternative diagnoses; exposure to risk factors (e.g., infectious, occupational, and environmental agents); and exposure to drugs taken for therapeutic or recreational purposes. The clinical history, physical examination and, above all, chest computed tomography indicate which differential diagnoses are most likely, thereby guiding the choice of subsequent investigations (e.g., microbiological investigations, lymphocyte proliferation tests with metals, autoantibody assays, and genetic tests). The goal is to rule out all diagnoses other than sarcoidosis that are consistent with the clinical situation. Chest computed tomography findings, from common to rare and from typical to atypical, are described for sarcoidosis and the alternatives. The pathology of granulomas and associated lesions is discussed and diagnostically helpful stains specified. In some patients, the definite diagnosis may require the continuous gathering of information during follow-up. Diseases that often closely mimic sarcoidosis include chronic beryllium disease and drug-induced granulomatosis. Tuberculosis rarely resembles sarcoidosis but is a leading differential diagnosis in regions of high tuberculosis endemicity.

An improved Yolov5s based on transformer backbone network for detection and classification of bronchoalveolar lavage cells

Biological tissue information of the lung, such as cells and proteins, can be obtained from bronchoalveolar lavage fluid (BALF), through which it can be used as a complement to lung biopsy pathology. BALF cells can be confused with each other due to the similarity of their characteristics and differences in the way sections are handled or viewed. This poses a great challenge for cell detection. In this paper, An Improved Yolov5s Based on Transformer Backbone Network for Detection and Classification of BALF Cells is proposed, focusing on the detection of four types of cells in BALF: macrophages, lymphocytes, neutrophils and eosinophils. The network is mainly based on the Yolov5s network and uses Swin Transformer V2 technology in the backbone network to improve cell detection accuracy by obtaining global information; the C3Ghost module (a variant of the Convolutional Neural Network architecture) is used in the neck network to reduce the number of parameters during feature channel fusion and to improve feature expression performance. In addition, embedding intersection over union Loss (EIoU_Loss) was used as a bounding box regression loss function to speed up the bounding box regression rate, resulting in higher accuracy of the algorithm. The experiments showed that our model could achieve mAP of 81.29% and Recall of 80.47%. Compared to the original Yolov5s, the mAP has improved by 3.3% and Recall by 3.67%. We also compared it with Yolov7 and the newly launched Yolov8s. mAP improved by 0.02% and 2.36% over Yolov7 and Yolov8s respectively, while the FPS of our model was higher than both of them, achieving a balance of efficiency and accuracy, further demonstrating the superiority of our model.

The impact of bronchoalveolar lavage on the diagnosis of undifferentiated interstitial lung disease alongside a multidisciplinary discussion

BACKGROUND AND OBJECTIVE

Cellular analysis of bronchoalveolar lavage (BAL) fluid may aid diagnosis in patients with undifferentiated interstitial lung disease (ILD). The utility of this test in the diagnostic process in conjunction with a multidisciplinary discussion (MDD) is not known. We aim to assess and compare interobserver agreement and diagnostic confidence before and after presenting BAL results in an ILD-MDD.

METHODS

Patients undergoing investigations for ILD at Waikato Hospital were recruited. At the ILD-MDD two respiratory physicians and one respiratory radiologist participated in the discussion, and their diagnosis and diagnostic confidence were assessed at four sequential time points. Assessors were blinded to each others diagnosis and diagnostic confidence scores. The four sequential time points were (1) after clinical and radiology presentation; (2) after subsequent MDD; (3) after reviewing BAL results; (4) after final MDD with all results. Interobserver agreements were calculated using Fleiss κ statistic.

RESULTS

36 patients were recruited, and 77.8% were male. In the first step, the interobserver agreement was substantial κ = 0.622 (95% CI 0.47-0.77), improving in step 2 following MDD to κ = 0.78 (95% CI 0.624-0.935), in step 3 κ = 0.776 (95% CI 0.614-0.937) and step 4 achieved almost perfect agreement of κ = 0.969 (95% CI 0.828-1.11). The diagnostic confidence for individual and group diagnosis increased with the presentation of BAL with and without multidisciplinary MDD.

CONCLUSION

We found that BAL cellular analysis improves interobserver agreement and confidence in diagnosis following MDD, thus aiding decision-making in cases with undifferentiated ILD.

Prognostic Implication of Exfoliative Airway Pathology in Cancer-Free Coal Workers' Pneumoconiosis

BACKGROUND

The purpose of this study is to see if exfoliative pulmonary airway pathology in cancer-free coal workers' pneumoconiosis (CWP) can be used as a biomarker for predicting pulmonary morbidity.

METHODS

We investigated persistent metaplastic changes in bronchoscopic washing cytology and differential cell counts in bronchoalveolar lavages (BAL) in 97 miners with CWP and 80 miners without CWP as the control. Clinicopathological parameters were examined including pulmonary function tests and the presence of progressive massive fibrosis.

RESULTS

When compared to the control group, severe alveolitis, severe goblet cell hyperplasia (GCH), severe hyperplastic epithelial change, and severe squamous metaplasia were the distinguishing biomarkers in CWP. Multivariate analysis revealed that severe alveolitis and severe GCH, along with miner duration and current smoker, were independent predictors of pulmonary mortality. The survival analysis revealed a significantly different survival rate between the three groups: no evidence of severe alveolitis and severe GCH, presence of severe alveolitis or severe GCH but not both, and both severe alveolitis and severe GCH.

CONCLUSIONS

The severities of alveolitis and goblet cell hyperplasia in the bronchoscopic study are independent prognostic factors for CWP. A pathologic grading system based on these two parameters could be used in the stratification and clinical management of CWP patients.

[French practical guidelines for the diagnosis and management of IPF - 2021 update, full version]

BACKGROUND

Since the previous French guidelines were published in 2017, substantial additional knowledge about idiopathic pulmonary fibrosis has accumulated.

METHODS

Under the auspices of the French-speaking Learned Society of Pulmonology and at the initiative of the coordinating reference center, practical guidelines for treatment of rare pulmonary diseases have been established. They were elaborated by groups of writers, reviewers and coordinators with the help of the OrphaLung network, as well as pulmonologists with varying practice modalities, radiologists, pathologists, a general practitioner, a head nurse, and a patients' association. The method was developed according to rules entitled "Good clinical practice" in the overall framework of the "Guidelines for clinical practice" of the official French health authority (HAS), taking into account the results of an online vote using a Likert scale.

RESULTS

After analysis of the literature, 54 recommendations were formulated, improved, and validated by the working groups. The recommendations covered a wide-ranging aspects of the disease and its treatment: epidemiology, diagnostic modalities, quality criteria and interpretation of chest CT, indication and modalities of lung biopsy, etiologic workup, approach to familial disease entailing indications and modalities of genetic testing, evaluation of possible functional impairments and prognosis, indications for and use of antifibrotic therapy, lung transplantation, symptom management, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis.

CONCLUSION

These evidence-based guidelines are aimed at guiding the diagnosis and the management in clinical practice of idiopathic pulmonary fibrosis.

French practical guidelines for the diagnosis and management of idiopathic pulmonary fibrosis - 2021 update. Full-length version

BACKGROUND

Since the latest 2017 French guidelines, knowledge about idiopathic pulmonary fibrosis has evolved considerably.

METHODS

Practical guidelines were drafted on the initiative of the Coordinating Reference Center for Rare Pulmonary Diseases, led by the French Language Pulmonology Society (SPLF), by a coordinating group, a writing group, and a review group, with the involvement of the entire OrphaLung network, pulmonologists practicing in various settings, radiologists, pathologists, a general practitioner, a health manager, and a patient association. The method followed the "Clinical Practice Guidelines" process of the French National Authority for Health (HAS), including an online vote using a Likert scale.

RESULTS

After a literature review, 54 guidelines were formulated, improved, and then validated by the working groups. These guidelines addressed multiple aspects of the disease: epidemiology, diagnostic procedures, quality criteria and interpretation of chest CT scans, lung biopsy indication and procedures, etiological workup, methods and indications for family screening and genetic testing, assessment of the functional impairment and prognosis, indication and use of antifibrotic agents, lung transplantation, management of symptoms, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis.

CONCLUSION

These evidence-based guidelines are intended to guide the diagnosis and practical management of idiopathic pulmonary fibrosis.

Sarcoid Uveitis: An Intriguing Challenger

The purpose of our work is to describe the actual knowledge concerning etiopathogenesis, clinical manifestations, diagnostic procedures, complications and therapy of ocular sarcoidosis (OS). The study is based on a recent literature review and on the experience of our tertiary referral center. Data were retrospectively analyzed from the electronic medical records of 235 patients (461 eyes) suffering from a biopsy-proven ocular sarcoidosis. Middle-aged females presenting bilateral ocular involvement are mainly affected; eye involvement at onset is present in one-third of subjects. Uveitis subtype presentation ranges widely among different studies: panuveitis and multiple chorioretinal granulomas, retinal segmental vasculitis, intermediate uveitis and vitreitis, anterior uveitis with granulomatous mutton-fat keratic precipitates, iris nodules, and synechiae are the main ocular features. The most important complications are cataract, glaucoma, cystoid macular edema (CME), and epiretinal membrane. Therapy is based on the disease localization and the severity of systemic or ocular involvement. Local, intravitreal, or systemic steroids are the mainstay of treatment; refractory or partially responsive disease has to be treated with conventional and biologic immunosuppressants. In conclusion, we summarize the current knowledge and assessment of ophthalmological inflammatory manifestations (mainly uveitis) of OS, which permit an early diagnostic assay and a prompt treatment.

Characterization of ENM Dynamic Dose-Dependent MOA in Lung with Respect to Immune Cells Infiltration

The molecular effects of exposures to engineered nanomaterials (ENMs) are still largely unknown. In classical inhalation toxicology, cell composition of bronchoalveolar lavage (BAL) is a toxicity indicator at the lung tissue level that can aid in interpreting pulmonary histological changes. Toxicogenomic approaches help characterize the mechanism of action (MOA) of ENMs by investigating the differentially expressed genes (DEG). However, dissecting which molecular mechanisms and events are directly induced by the exposure is not straightforward. It is now generally accepted that direct effects follow a monotonic dose-dependent pattern. Here, we applied an integrated modeling approach to study the MOA of four ENMs by retrieving the DEGs that also show a dynamic dose-dependent profile (dddtMOA). We further combined the information of the dddtMOA with the dose dependency of four immune cell populations derived from BAL counts. The dddtMOA analysis highlighted the specific adaptation pattern to each ENM. Furthermore, it revealed the distinct effect of the ENM physicochemical properties on the induced immune response. Finally, we report three genes dose-dependent in all the exposures and correlated with immune deregulation in the lung. The characterization of dddtMOA for ENM exposures, both for apical endpoints and molecular responses, can further promote toxicogenomic approaches in a regulatory context.

Diagnosis of Hypersensitivity Pneumonitis: Review and Summary of American College of Chest Physicians Statement

Assessment of lung biopsies for the diagnosis of hypersensitivity pneumonitis (HP) is one of the most difficult diagnostic problems for surgical pathologists. It is a form of interstitial lung disease resulting from an immune reaction provoked by an inhaled antigen in susceptible individuals. Although this definition sounds simple, in practice, the diagnosis of HP can be challenging. To address these issues, the American College of Chest Physicians (CHEST) has recently published a guideline for the diagnosis of HP. In this review, we will explore the multidisciplinary diagnostic evaluation of HP with a focus on the pathologic features as outlined in the CHEST guidelines. The histologic criteria are divided into 4 diagnostic categories: (1) Typical nonfibrotic HP or fibrotic HP; (2) Compatible with nonfibrotic HP or fibrotic HP; (3) Indeterminate for nonfibrotic or fibrotic HP; and (4) Alternative Diagnosis. It is important to emphasize that patterns 1 to 3 do not represent discrete histologic entities or pathologic diagnoses. Rather, these categories are meant to serve as a practical guide for organizing a complex set of overlapping histologic patterns into an integrated diagnostic framework for facilitating multidisciplinary discussion. High-resolution computed tomography features are also summarized, emphasizing how the correlation of lung biopsies with computed tomography findings can help to favor the diagnosis, particularly in cases where biopsies are not typical for HP. This review highlights details of the histologic spectrum of HP as well as the utility of different types of biopsies and bronchoalveolar lavage. We also emphasize the importance of multidisciplinary discussion and the complex differential diagnosis.

Hypersensitivity pneumonitis: Current concepts in pathogenesis, diagnosis, and treatment

Hypersensitivity pneumonitis is an immune-mediated interstitial lung disease caused by an aberrant response to an inhaled exposure, which results in mostly T cell-mediated inflammation, granuloma formation, and fibrosis in some cases. HP is diagnosed by exposure identification, HRCT findings of ground-glass opacities, centrilobular nodules, and mosaic attenuation, with traction bronchiectasis and honeycombing in fibrotic cases. Additional testing including serum IgG testing for the presence of antigen exposure, bronchoalveolar lavage lymphocytosis, and lung biopsy demonstrating granulomas, inflammation, and fibrosis, increases the diagnostic confidence. Treatment for HP includes avoidance of the implicated exposure, immunosuppression, and anti-fibrotic therapy in select cases. This narrative review presents the recent literature in the understanding of the immunopathological mechanisms, diagnosis, and treatment of HP.

Transbronchial biopsy vs. bronchoalveolar lavage in interstitial lung disease

PURPOSE OF REVIEW

Interstitial lung diseases (ILDs) are heterogeneous disorders characterized by varying degrees of inflammation and fibrosis in the lung parenchyma. The use of bronchoalveolar lavage (BAL) cellular analysis and transbronchial biopsy with forceps (TBLB) in ILD is often a matter of debate. ILDs have been a diagnostic challenge and require multidisciplinary discussion (MDD) to develop a consensus diagnosis based on clinical, radiologic, laboratory, BAL cellular analysis, and histologic information.

RECENT FINDINGS

The BAL cellular analysis is a commonly performed tool, and some ILDs have distinctive cellular findings. Its use alone is seldom diagnostic and almost always requires clinical, radiologic findings, and or histologic information interpretation. The minimally invasive procedures, such as TBLB, transbronchial cryo-biopsy (TBCB), and invasive procedures, such as surgical lung biopsy (SLB) help obtain a histologic diagnosis.

SUMMARY

This review serves as a resource to assist clinicians to develop effective communication and close collaboration through MDD for accurate selection of diagnostic tools to reach the correct and final diagnosis.

Bronchoalveolar Lavage Complements Transbronchial Cryobiopsy Diagnosis in Diffuse Interstitial Lung Diseases

BACKGROUND

Bronchoalveolar lavage (BAL) is a technique classically used for the study of diffuse interstitial lung diseases (DILDs). Given the recent advances in the diagnosis of DILD by transbronchial cryobiopsy (TBCB), it is relevant to assess what BAL can contribute to TBCB.

PATIENTS AND METHODS

This is a retrospective descriptive study that included patients with DILD who, between 2013 and 2017, underwent BAL and TBCB in the same bronchoscopy intervention. We evaluated the complementary information provided by BAL to TBCB that facilitated the diagnosis by a multidisciplinary committee. Epidemiological, clinical, and functional variables and high-resolution chest tomography findings were recorded, along with complications associated with the procedures.

RESULTS

A total of 60 patients were included. TBCB, conditioned by the underlying radiologic pattern, provided diagnostic information in 75% of cases. BAL provided complementary information that supported the diagnosis and treatment in 22% of cases. Differential BAL findings were related to microbiology, cell count, and immunology. Regarding the safety of the procedure, 47% of the patients experienced complications, although none were serious.

CONCLUSION

BAL findings contribute to TBCB findings in the diagnosis of DILDs, with no serious complications associated with their combined use.

Pulmonary Sarcoidosis: Diagnosis and Differential Diagnosis

Sarcoidosis is a multisystem disorder of unknown origin and poorly understood pathogenesis that predominantly affects lungs and intrathoracic lymph nodes and is characterized by the presence of noncaseating granulomatous inflammation in involved organs. The disease is highly heterogeneous and can mimic a plethora of other disorders, making diagnosis a challenge even for experienced physicians. The evolution and severity of sarcoidosis are highly variable: many patients are asymptomatic and their disease course is generally benign with spontaneous resolution. However, up to one-third of patients develop chronic or progressive disease mainly due to pulmonary or cardiovascular complications that require long-term therapy. The diagnosis of sarcoidosis requires histopathological evidence of noncaseating granulomatous inflammation in one or more organs coupled with compatible clinical and radiological features and the exclusion of other causes of granulomatous inflammation; however, in the presence of typical disease manifestations such as Löfgren’s syndrome, Heerfordt’s syndrome, lupus pernio and asymptomatic bilateral and symmetrical hilar lymphadenopathy, the diagnosis can be established with high level of certainty on clinical grounds alone. This review critically examines the diagnostic approach to sarcoidosis and emphasizes the importance of a careful exclusion of alternative diagnoses.

Bronchoalveolar Lavage Lymphocytes in the Diagnosis of Hypersensitivity Pneumonitis among Patients with Interstitial Lung Disease

Rationale: Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) characterized by inflammation and/or fibrosis in response to an inhalational exposure.Objectives: To determine the value of bronchoalveolar lavage (BAL) fluid lymphocyte cellular analysis in the detection of HP among patients with newly detected ILD.Methods: This systematic review was undertaken in the context of development of an American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax clinical practice guideline. The clinical question was, "should patients with newly detected ILD undergo BAL fluid lymphocyte analysis to diagnose HP?" MEDLINE, EMBASE, and the gray literature were searched through October 2019. Studies that reported the percentage of BAL fluid lymphocytes for various ILDs were selected for inclusion. Meta-analyses compared the mean percentage of BAL fluid lymphocytes among patients with HP with that among patients with idiopathic pulmonary fibrosis (IPF) or sarcoidosis. The sensitivity and specificity by which various percentages of BAL fluid lymphocytes distinguish HP from IPF and sarcoidosis were also evaluated.Results: Eighty-four articles were selected. No randomized trials or observational studies were identified that compared BAL fluid lymphocyte analysis with no BAL fluid lymphocyte analysis in patients with ILD. Included studies were case series describing BAL fluid cell differentials in patients with various ILDs. The percentage of BAL fluid lymphocytes was significantly higher in both fibrotic and nonfibrotic HP compared with IPF. Similarly, the percentage of BAL fluid lymphocytes was significantly higher in both fibrotic and nonfibrotic HP compared with sarcoidosis. A threshold of 20% BAL fluid lymphocytes distinguished fibrotic HP from IPF with a sensitivity and specificity of 69% and 61%, respectively, and nonfibrotic HP from IPF with a sensitivity and specificity of 95% and 61%, respectively. It distinguished fibrotic HP from sarcoidosis with a sensitivity and specificity of 69% and 26%, respectively, and nonfibrotic HP from sarcoidosis with a sensitivity and specificity of 95% and 26%, respectively.Conclusions: The percentage of BAL fluid lymphocytes is higher in HP than IPF or sarcoidosis. However, a threshold that distinguishes HP from IPF or sarcoidosis with both high sensitivity and high specificity was not identified.

Recommendations for immunocytochemistry in lung cancer typing: An update on a resource-efficient approach with large-scale comparative Bayesian analysis

OBJECTIVES

The majority of lung cancer cases are of advanced stage and diagnosis is usually made using minimally invasive small biopsies and cytological specimens. The WHO 2015 classification recommends limiting immunocytochemistry (ICC) to lung cancer typing and molecular testing drives for personalised therapies. An algorithm using Bayes' theorem could be useful for defining antibody profiles. This study aims to assess the impact of different antibody profiles for cytological samples on the accuracy of lung cancer typing with a large-scale Bayesian analysis.

METHODS

A retrospective examination of 3419 consecutive smears and/or cytospins diagnosed over 2011-2016 found 1960 primary lung cancer tumours: 972 adenocarcinomas (ADC), 256 squamous carcinomas (SQC), 268 neuroendocrine tumours (NET), and 464 non-small cell cancer-not otherwise specified (NSCC-NOS). The a priori and a posteriori probabilities, before and after ICC using antibodies singly or in combination, were calculated for different lung cancer types.

RESULTS

TTF-1 or CK7 alone improved the a posteriori probabilities of correct cytological typing for ADC to 86.5% and 95.8%, respectively. For SQC, using p40 (∆Np63) or CK5/6 together with CK5/14 led to comparable results (78.3% and 90.3%). With synaptophysin or CD56 alone, improvements in a posteriori probabilities to 87.5 and 90.3% for the correct recognition of NET could be achieved.

CONCLUSIONS

Based on morphological and clinical data, the use of two antibodies appears sufficient for reliable detection of the different lung cancer types. This applies to diagnoses that were finalised following ICC both on a clinical or cytological basis and on a histological basis.

Diagnostic and prognostic implications of 2018 guideline for the diagnosis of idiopathic pulmonary fibrosis in clinical practice

The purpose of this study was to evaluate the implications of the 2018 updated guideline for the diagnosis of idiopathic pulmonary fibrosis (IPF) in clinical practice compared to 2011 guideline. This study involved 535 patients including 339 IPF and 196 non-IPF, and we retrospectively evaluated CT classifications of usual interstitial pneumonia (UIP) by two guidelines. Interobserver agreement of 2018 criteria showed moderate reliability (κ = 0.53) comparable to 2011 (κ = 0.56) but interobserver agreement for probable UIP was fair (κ = 0.40). CT pattern of indeterminate for UIP was associated with better prognosis compared with the other groups (adjusted hazard ratio [HR] = 0.36, p < 0.001). Compared to possible UIP, probable UIP demonstrated a lower positive predictive value (PPV, 62.9% vs 65.8%). In analysis of patients with CT patterns of non-definite UIP, diagnosing IPF when CT pattern showed probable UIP with lymphocyte count ≤ 15% in BAL fluid, and either male sex or age ≥ 60 years showed a high specificity of 90.6% and a PPV of 80.8% in the validation cohort. The 2018 criteria provide better prognostic stratification than the 2011 in patients with possible UIP. BAL fluid analysis can improve the diagnostic certainty for IPF diagnosis in patients with probable UIP CT pattern.

Integrated approach to bronchoalveolar lavage cytology to distinguish interstitial lung diseases

BACKGROUND

Broncho-alveolar lavage (BAL) is a safe diagnostic procedure, useful for differentiating fibrotic lung disorders and for excluding malignancy and infection. A recent multicenter study demonstrated a new, relatively sensitive, and specific index called Bronchoalveolar Cytology Threshold (BCT), useful for distinguishing healthy individuals from patients with lung diseases.

OBJECTIVES

In our study, BCT was applied for the first time to the analysis of interstitial lung diseases (ILDs), investigating its potential for differential diagnosis. Combinations of BAL cells that improve diagnostic accuracy for ILDs were studied and are proposed.

METHODS

A retrospective analysis of BAL samples was performed. We considered more than 1000 BAL samples from patients investigated for ILD, performed at Siena University Hospital. The samples enrolled for the study included 468 patients: 413 with and 55 without ILD. BAL was performed for diagnostic purposes in line with international guidelines. BCT were calculated according to available literature.

RESULTS

Among ILDs, patients with fibrotic hypersensitivity pneumonitis, idiopathic pulmonary fibrosis (IPF) and sarcoidosis showed significantly lower BCTs than unclassified ILD. Asbestosis patients showed significantly lower BCTs than nonspecific interstitial pneumonia (NSIP), cryptogenic organizing pneumonia (COP), connective tissue disease related ILD (CTD-ILD), sarcoidosis and unclassified ILD patients. COP patients showed significantly higher BCT than IPF, f-HP and sarcoidosis. Moreover, COP patients were best distinguished by BCT.

CONCLUSION

The analysis of BAL features is currently included in the diagnostic algorithm of ILDs. BAL cell patterns and BCT index can provide useful information for distinguishing ILDs, reducing the need for invasive procedures. Integrated approaches to BAL analysis can improve the interpretation of results without further cost or loss of time.

Occupational exposures and idiopathic pulmonary fibrosis

PURPOSE OF REVIEW

A recent meta-analysis of data from international case-control studies reports a population attributable fraction of 16% for occupational factors in the cause of idiopathic pulmonary fibrosis (IPF). Smoking, genetic factors and other prevalent diseases only partly explain IPF, and so this review aims to summarize recent progress in establishing which occupational exposures are important in cause.

RECENT FINDINGS

IPF is a rare disease, although it is the commonest idiopathic interstitial pneumonia. Epidemiological study suggests that incidence of IPF is increasing, particularly in older men. There are significant associations with IPF and occupational exposures to organic dust, including livestock, birds and animal feed, metal dust, wood dust and silica/minerals. Estimates of effect vary between studies, and are influenced by the distribution of employment, study design and case definition. Inhalation of asbestos fibres is a known cause of usual interstitial pneumonia (as seen histologically in IPF), though there are significant linear relationships between asbestos consumption, and mortality from both IPF and mesothelioma, leading to the hypothesis that low-level asbestos exposure may cause IPF.

SUMMARY

Research must focus on exposure-response relationships between asbestos and other occupational inhaled hazards, and IPF. Funding bodies and policy makers should acknowledge the significant occupational burden on IPF.

Diagnosis and Evaluation of Hypersensitivity Pneumonitis: CHEST Guideline and Expert Panel Report

BACKGROUND

The purpose of this analysis is to provide evidence-based and consensus-derived guidance for clinicians to improve individual diagnostic decision-making for hypersensitivity pneumonitis (HP) and decrease diagnostic practice variability.

STUDY DESIGN AND METHODS

Approved panelists developed key questions regarding the diagnosis of HP using the PICO (Population, Intervention, Comparator, Outcome) format. MEDLINE (via PubMed) and the Cochrane Library were systematically searched for relevant literature, which was supplemented by manual searches. References were screened for inclusion, and vetted evaluation tools were used to assess the quality of included studies, to extract data, and to grade the level of evidence supporting each recommendation or statement. The quality of the evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Graded recommendations and ungraded consensus-based statements were drafted and voted on using a modified Delphi technique to achieve consensus. A diagnostic algorithm is provided, using supporting data from the recommendations where possible, along with expert consensus to help physicians gauge the probability of HP.

RESULTS

The systematic review of the literature based on 14 PICO questions resulted in 14 key action statements: 12 evidence-based, graded recommendations and 2 ungraded consensus-based statements. All evidence was of very low quality.

INTERPRETATION

Diagnosis of HP should employ a patient-centered approach and include a multidisciplinary assessment that incorporates the environmental and occupational exposure history and CT pattern to establish diagnostic confidence prior to considering BAL and/or lung biopsy. Criteria are presented to facilitate diagnosis of HP. Additional research is needed on the performance characteristics and generalizability of exposure assessment tools and traditional and new diagnostic tests in modifying clinical decision-making for HP, particularly among those with a provisional diagnosis.

Executive Summary: Diagnosis and Evaluation of Hypersensitivity Pneumonitis: CHEST Guideline and Expert Panel Report

BACKGROUND

The purpose of this summary is to provide a synopsis of evidence-based and consensus-derived guidance for clinicians to improve individual diagnostic decision-making for hypersensitivity pneumonitis (HP) and decrease diagnostic practice variability.

STUDY DESIGN AND METHODS

Approved panelists developed key questions regarding the diagnosis of HP using the PICO (Population, Intervention, Comparator, and Outcome) format. MEDLINE (via PubMed) and the Cochrane Library were systematically searched for relevant literature, which was supplemented by manual searches. References were screened for inclusion and vetted evaluation tools were used to assess the quality of included studies, to extract data, and to grade the level of evidence supporting each recommendation or statement. The quality of the evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Graded recommendations and ungraded consensus-based statements were drafted and voted on using a modified Delphi technique to achieve consensus.

RESULTS

The systematic review of the literature based on 14 PICO questions resulted in 14 key action statements: 12 evidence-based, graded recommendations, and 2 ungraded consensus-based statements. All evidence was of very low quality.

INTERPRETATION

Diagnosis of HP should employ a patient-centered approach and include a multidisciplinary assessment that incorporates the environmental and occupational exposure history and CT pattern to establish diagnostic confidence prior to considering BAL and/or lung biopsy. Additional research is needed on the performance characteristics and generalizability of exposure assessment tools and traditional and new diagnostic tests in modifying clinical decision-making for HP, particularly among those with a provisional diagnosis.

Computed Tomography Findings as Determinants of Local and Systemic Inflammation Biomarkers in Interstitial Lung Diseases: A Retrospective Registry-Based Descriptive Study

PURPOSE

To evaluate the association of peripheral blood (PBL) and broncho-alveolar lavage (BAL) biomarkers with inflammatory versus fibrotic high-resolution computed tomography (HRCT) findings in interstitial lung disease (ILD) patients.

METHODS

HRCT findings of 127 consecutive ILD-board patients were semi-quantitatively evaluated: reticulation/honeycombing (RET), traction bronchiectasis (TBR) and emphysema (EMP) were classified as non-inflammatory/fibrotic; consolidations (CON), ground glass opacities (GGO), parenchymal nodules (NDL) and mosaic attenuation (MOS) as active inflammatory. Each HRCT finding was assessed in six distinct lung regions, resulting scores were graded as minimal (0-1 regions involved), medium (2-4) or extensive (5-6). Associations of routinely assessed PBL/BAL biomarkers with these HRCT scores were evaluated using Spearman correlation coefficients and graphical presentation; significance was tested by applying Kruskal-Wallis tests.

RESULTS

Blood neutrophil, lymphocyte and eosinophil fraction, neutrophil to lymphocyte ratio (NLR) and BAL lymphocyte fraction consistently showed opposite correlations with inflammatory versus non-inflammatory/fibrotic HRCT finding scores. Blood lymphocyte fraction significantly differed by graded GGO (p = 0.032) and CON (p = 0.027) extent, eosinophil fraction by TBR (p = 0.006) and NLR by CON (p = 0.009). C-reactive protein was significantly related to GGO (p = 0.023) and CON (p = 0.004), BAL lymphocyte fraction to GGO (p = 0.017) extent.

CONCLUSION

Blood lymphocyte and eosinophil fraction, NLR, CRP and BAL lymphocyte fraction may aid to differentiate inflammatory from non-inflammatory/fibrotic ILD patterns.

TRIAL REGISTRATION

This evaluation was based on data from the ILD registry of Kepler University Hospital Linz, as approved by the ethics committee of the Federal State of Upper-Austria (EK Number. I-26-17).

S2K Guideline for Diagnosis of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a severe and often fatal disease. Diagnosis of IPF requires considerable expertise and experience. Since the publication of the international IPF guideline in the year 2011 and the update 2018 several studies and technical advances have occurred, which made a new assessment of the diagnostic process mandatory. The goal of this guideline is to foster early, confident, and effective diagnosis of IPF. The guideline focusses on the typical clinical context of an IPF patient and provides tools to exclude known causes of interstitial lung disease including standardized questionnaires, serologic testing, and cellular analysis of bronchoalveolar lavage. High-resolution computed tomography remains crucial in the diagnostic workup. If it is necessary to obtain specimens for histology, transbronchial lung cryobiopsy is the primary approach, while surgical lung biopsy is reserved for patients who are fit for it and in whom a bronchoscopic diagnosis did not provide the information needed. After all, IPF is a diagnosis of exclusion and multidisciplinary discussion remains the golden standard of diagnosis.

Key Players and Biomarkers of the Adaptive Immune System in the Pathogenesis of Sarcoidosis

Sarcoidosis is a systemic inflammatory disease characterized by development of granulomas in the affected organs. Sarcoidosis is often a diagnosis of exclusion, and traditionally used tests for sarcoidosis demonstrate low sensitivity and specificity. We propose that accuracy of diagnosis can be improved if biomarkers of altered lymphocyte populations and levels of signaling molecules involved in disease pathogenesis are measured for patterns suggestive of sarcoidosis. These distinctive biomarkers can also be used to determine disease progression, predict prognosis, and make treatment decisions. Many subsets of T lymphocytes, including CD8⁺ T-cells and regulatory T-cells, have been shown to be dysfunctional in sarcoidosis, and the predominant CD4⁺ T helper cell subset in granulomas appears to be a strong indicator of disease phenotype and outcome. Studies of altered B cell populations, B cell signaling molecules, and immune complexes in sarcoidosis patients reveal promising biomarkers as well as possible explanations of disease etiology. Furthermore, examined biomarkers raise questions about new treatment methods and sarcoidosis antigens.

Bronchoalveolar lavage as a diagnostic procedure: a review of known cellular and molecular findings in various lung diseases

Bronchoalveolar lavage (BAL) is a commonly used procedure in the evaluation of lung disease as it allows for sampling of the lower respiratory tract. In many circumstances, BAL differential cell counts have been reported to be typical of specific lung disorders. In addition, more specific diagnostic tests including molecular assays such as polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay, special cytopathologic stains, or particular microscopic findings have been described as part of BAL fluid analysis. This review focuses on common cellular and molecular findings of BAL in a wide range of lung diseases. Since the performance of the first lung irrigation in 1927, BAL has become a common and important diagnostic tool. While some pulmonary disorders have a highly characteristic signature of BAL findings, BAL results alone often lack specificity and require interpretation along with other clinical and radiographic details. Development of new diagnostic assays is certain to reinforce the utility of BAL in the future. Our review of the BAL literature is intended to serve as a resource to assist clinicians in the care of patients with lung disorders.

Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.

Analysis of bronchoalveolar lavage samples collected from 30 patients with drug-induced pneumonitis

BACKGROUND

Drug-induced pneumonitis is a disease encountered by pulmonologists in the clinical setting. The diagnosis generally considers the patient's clinical course and the results of peripheral blood tests, radiological examinations, and often bronchoscopic examinations. However, few studies have reported the association between radiological patterns such as ground-glass opacity (GGO) or consolidation, and bronchoalveolar lavage fluid (BALF) cell fractions. This study aimed to clarify this association.

METHODS

Patients with a Naranjo's score of probable or definite were enrolled, and all 30 patients were categorized under probable. Data such as patient background, blood examination results, radiological findings, and BALF cell fractions were retrospectively collected. The association between BALF cell fractions and other factors such as chest computed tomography (CT) findings was evaluated.

RESULTS

The most common radiological finding in patients with lymphocyte-dominant BALF was GGO, with only one patient exhibiting consolidation. However, patients with eosinophil-dominant BALF were more likely to have consolidation; only three cases showed crazy paving and one showed GGO. In addition, patients with a GGO-dominant pattern on CT had an increased lymphocyte fraction of 41.0%; those with a consolidation-dominant pattern showed a relatively high eosinophil fraction of 5.2%; and those with a crazy paving pattern showed elevated eosinophil and neutrophil fractions of 19.1% and 9.9%, respectively.

CONCLUSIONS

In this study, a remarkable difference in radiological findings was observed among different BALF patterns.

The value of bronchoalveolar lavage for discrimination between healthy and diseased individuals

BACKGROUND

Bronchoalveolar lavage (BAL) is standard diagnostic procedure. Procedural recommendations have been made by pneumological societies including normal values for interpretation of BAL cytology. These normal values derive from small studies in healthy volunteers and have never been analysed for their sensitivity and specificity.

OBJECTIVES

This study aims to analyse sensitivity and specificity of these normal values by assessing lavage cell composition in healthy and diseased individuals.

METHODS

More than 6000 BAL were retrospectively analysed for their cellular distribution including BALs of 250 healthy individuals. All BALs were obtained under similar conditions.

RESULTS

Bronchoalveolar lavage cytology of healthy individuals mirrors data from previous studies with smoking being the most important manipulator of BAL cytology. Analyses of proposed normal values demonstrate specificity between 80% and 95%, whereas sensitivity ranges between 35% and 65%. Using different mathematical models, a value summing up the differences to ATS-proposed normal values of the cytological pattern was found to best discriminate between healthy and diseased individuals with a sensitivity of nearly 60% with a predefined specificity of 95%.

CONCLUSION

In summary, our analysis confirmed prior results for healthy volunteers and enlarged these findings by analysing sensitivity and specificity of lavage results in an independent validation cohort of diseased individuals. Thereby, the study may influence the acceptance of BAL in the diagnostic workup of individuals with pulmonary diseases. Additionally, the study proposes a novel value that facilitates lavage interpretation and may therefore be useful in further studies.

Diagnosis issues in sarcoidosis

Multiple problems may be encountered during the diagnosis of sarcoidosis: at first diagnose sarcoidosis in an appropriate clinical setting, secondly, identify any manifestation to be linked to sarcoidosis at diagnosis work-up and during evolution; thirdly, recognize "danger" in sarcoidosis and parasarcoidosis syndromes, and finally, diagnose sarcoidosis recovery. Diagnosis is often delayed as presentation may be diverse, non-specific, or atypical. Diagnosis of sarcoidosis is based on three criteria: a compatible presentation; evidence of non-caseating granulomas and exclusion of any alternative diagnosis. However, even when all criteria are fulfilled, the probability of sarcoidosis diagnosis varies from definite to only possible depending upon the presence of more or less characteristic radio-clinical and histopathological findings and on the epidemiological context. Bilateral hilar lymphadenopathy and/or diffuse lung micronodules mainly along lymphatics are the most frequent highly suggestive findings. Evidence of granulomas relies on superficial biopsies of clinically suspected lesion when present or most often by bronchial endoscopy. The diagnosis of sarcoidosis may be difficult in absence of thoracic or skin manifestations and may require the benefit of hindsight before being definitive. Differential diagnoses, mainly tuberculosis, must be considered. The diagnosis of events during evolution relies on serial clinical, pulmonary function, radiographic evaluation and on extrapulmonary manifestations work-up, including electrocardiogram and blood biology. Affected organs need to be related to sarcoidosis using an appropriate diagnostic assessment instrument. To declare the recovery of sarcoidosis, all manifestations must have disappeared spontaneously or after 3-5 years post-treatment without relapse.

Diagnosis of Idiopathic Pulmonary Fibrosis. An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline

BACKGROUND

This document provides clinical recommendations for the diagnosis of idiopathic pulmonary fibrosis (IPF). It represents a collaborative effort between the American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Latin American Thoracic Society.

METHODS

The evidence syntheses were discussed and recommendations formulated by a multidisciplinary committee of IPF experts. The evidence was appraised and recommendations were formulated, written, and graded using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

RESULTS

The guideline panel updated the diagnostic criteria for IPF. Previously defined patterns of usual interstitial pneumonia (UIP) were refined to patterns of UIP, probable UIP, indeterminate, and alternate diagnosis. For patients with newly detected interstitial lung disease (ILD) who have a high-resolution computed tomography scan pattern of probable UIP, indeterminate, or an alternative diagnosis, conditional recommendations were made for performing BAL and surgical lung biopsy; because of lack of evidence, no recommendation was made for or against performing transbronchial lung biopsy or lung cryobiopsy. In contrast, for patients with newly detected ILD who have a high-resolution computed tomography scan pattern of UIP, strong recommendations were made against performing surgical lung biopsy, transbronchial lung biopsy, and lung cryobiopsy, and a conditional recommendation was made against performing BAL. Additional recommendations included a conditional recommendation for multidisciplinary discussion and a strong recommendation against measurement of serum biomarkers for the sole purpose of distinguishing IPF from other ILDs.

CONCLUSIONS

The guideline panel provided recommendations related to the diagnosis of IPF.

The cerebrospinal fluid CD4/CD8 ratio and interleukin-6 and -10 levels in neurosarcoidosis: a multicenter, pragmatic, comparative study

BACKGROUND AND PURPOSE

Neurosarcoidosis is a rare inflammatory disorder of unknown cause. The aim of this study was to evaluate the value of T/B lymphocyte population counts and the concentrations of the cytokines interleukin (IL) 6 and IL-10 in the cerebrospinal fluid (CSF) of neurosarcoidosis patients.

METHODS

A retrospective study CSF biomarkers was conducted in patients with neurosarcoidosis who underwent CSF analysis between 2012 and 2017 as well as various control populations.

RESULTS

Forty-three patients with neurosarcoidosis, 14 with multiple sclerosis (MS) and 48 with other inflammatory disorders were analyzed. The CSF IL-6 levels were higher in sarcoidosis patients than in MS patients (median 8 vs. 3 pg/ml, P = 0.006). The CSF CD4/CD8 ratio was higher in sarcoidosis patients than in MS patients and in patients with other inflammatory disorders (median 3.18 vs. 2.36 and 2.10, respectively, P = 0.008). The CSF IL-6 level was higher in patients with active neurosarcoidosis than in non-active neurosarcoidosis patients (median 13 vs. 3 pg/ml, P = 0.0005). In patients with neurosarcoidosis, a CSF IL-6 concentration >50 pg/ml was associated with a higher risk of relapse or progression-free survival (hazard ratio 3.60; 95% confidence interval 1.78-23.14). A refractory neurosarcoidosis patient was treated with an anti-IL-6 monoclonal antibody that produced a complete neurological response.

CONCLUSIONS

The CSF CD4/CD8 ratio and IL-6 concentration are increased in neurosarcoidosis compared to MS and other inflammatory disorders. A CSF IL-6 concentration >50 pg/ml is associated with relapse or progression of neurosarcoidosis. IL-10 levels may be elevated in neurosarcoidosis.

Development and validation of a radiological diagnosis model for hypersensitivity pneumonitis

High-resolution computed tomography (HRCT) may be useful for diagnosing hypersensitivity pneumonitis. Here, we develop and validate a radiological diagnosis model and model-based points score.Patients with interstitial lung disease seen at the University of Michigan Health System (derivation cohort) or enrolling in the Lung Tissue Research Consortium (validation cohort) were included. A thin-section, inspiratory HRCT scan was required. Thoracic radiologists documented radiological features.The derivation cohort comprised 356 subjects (33.9% hypersensitivity pneumonitis) and the validation cohort comprised 424 subjects (15.5% hypersensitivity pneumonitis). An age-, sex- and smoking status-adjusted logistic regression model identified extent of mosaic attenuation or air trapping greater than that of reticulation ("MA-AT>Reticulation"; OR 6.20, 95% CI 3.53-10.90; p<0.0001) and diffuse axial disease distribution (OR 2.33, 95% CI 1.31-4.16; p=0.004) as hypersensitivity pneumonitis predictors (area under the receiver operating characteristic curve 0.814). A model-based score >2 (1 point for axial distribution, 2 points for "MA-AT>Reticulation") has specificity 90% and positive predictive value (PPV) 74% in the derivation cohort and specificity 96% and PPV 44% in the validation cohort. Similar model performance is seen with population restriction to those reporting no exposure (score >2: specificity 91%).When radiological mosaic attenuation or air trapping are more extensive than reticulation and disease has diffuse axial distribution, hypersensitivity pneumonitis specificity is high and false diagnosis risk low (<10%), but PPV is diminished in a low-prevalence setting.

Clusterization of patients with idiopathic pulmonary fibrosis with chemokine receptors: a possible role in the diagnostic work-up of idiopathic pulmonary fibrosis?

Background and objective: Idiopathic pulmonary fibrosis (IPF) is a chronic and irreversible interstitial lung disease whose diagnosis often requires surgical lung biopsies (SLB) in cases without consistent radiological findings. We previously published that the expression of the chemokine receptors CXCR3 and CCR4 on T cells is significantly different in bronchoalveolar lavage (BAL) of IPF patients from other interstitial lung diseases. The aim of the study was to evaluate cut-off values of CXCR3 and CCR4 receptors expressed on bronchoalveolar lavage (BAL) and peripheral blood (PB) T cells useful for a differential diagnosis. Methods: Ninety-three patients were enrolled: 35 IPF, 36 interstitial lung diseases (nIPF) and 22 sarcoidosis. CXCR3 and CCR4 were evaluated on BAL and PB T lymphocytes with flow cytometry. Results: Among PB and BAL variables considered, the values of the ratio of BAL and PB CXCR3 on CD4 cells were clustered in the most informative way to obtain a classification rule for the diagnosis of patients without steroid therapy (n = 66/93). Patients with a CXCR3 ratio BAL/PB on CD4 T cells lower or equal than 1.43 were assigned to the IPF group with sensitivity = 0.87 and specificity = 0.90. All the other variables considered showed lower sensitivity and specificity in discriminating IPF patients. Conclusions: The evaluation of chemokine receptors on BAL and PB T lymphocytes could aid to discriminate IPF in subjects without steroid therapy, particularly in those patients with a high-resolution computed tomography (HRCT) non typical for Usual Interstitial Pneumonia (UIP). (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 35-43).

Hypersensitivity Pneumonitis Caused by a Home Ultrasonic Humidifier Contaminated with Candida guilliermondii

We herein report the first documented case of acute hypersensitivity pneumonitis in which Candida guilliermondii was the possible causative organism. A young Japanese woman presented to our hospital with relapsing respiratory symptoms accompanied by high fever. A detailed interview revealed that the onset of the symptoms occurred shortly after using a humidifier in her home. Her symptoms showed spontaneous improvement soon after admission, and an examination of her bronchoalveolar lavage fluid revealed the specific infiltration of inflammatory cells, which predominantly consisted of lymphocytes. Precipitin testing showed a positive reaction to C. guilliermondii, which was isolated from the home humidifier. Repeated history taking is essential for diagnosing occult respiratory disorders.

Interstitial lung disease: the diagnostic role of bronchoscopy

Interstitial lung diseases (ILDs) form one of the most fascinating fields in pulmonary medicine. They also pose one of the greatest challenges for accurate diagnosis and proper treatment. Even within the recommended and warranted multidisciplinary approach, differentiating between one disease and another may lead to frustration, especially when proper lung tissue is not available for adequate pathological review. A surgical lung biopsy (SLB) might render enough tissue for histopathology, but this could come at the expense of high morbidity and even mortality, as in the case of usual interstitial pneumonia (UIP). Could bronchoscopy and its various techniques offer a safer and higher yield alternative? Since the very late 19th century, efforts have been made to better examine the airways, obtain tissue and treat various conditions. This resulted in the successive emergence of bronchoalveolar lavage (BAL), endobronchial and transbronchial forceps biopsies, until recently when transbronchial cryobiopsy surfaced as a nascent technique with much promise. The use of endobronchial ultrasound revolutionized the diagnosis and staging of lung cancer, while adding to the yield of other conditions such as sarcoidosis. Ongoing research, efforts and studies have continuously scrutinized the roles of various techniques in the approach to ILDs. For example, BAL seems to serve mostly to eliminate infection as an etiology or a complicating factor in the acute worsening of a fibrotic lung disease, while a predominant cellular component might be diagnostic, such as eosinophilia in eosinophilic lung disease, or lymphocytosis in hypersensitivity pneumonitis (HP). On the other hand, endobronchial biopsy's (EBB) role appears limited to sarcoidosis. As for transbronchial biopsy by forceps, the small sample size and related artifact appear to be limiting factors in making an accurate diagnosis. Recently, however, the use of cryotherapy via employing a cryoprobe in obtaining transbronchial lung biopsies is unfolding into a refined interventional method which might transform indefinitely our approach to the pathological diagnosis of the various ILDs.

Fibrotic Hypersensitivity Pneumonitis: Key Issues in Diagnosis and Management

The diagnosis of hypersensitivity pneumonitis (HP) relies on the clinical evaluation of a number of features, including a history of significant exposure to potentially causative antigens, physical examination, chest CT scan appearances, bronchoalveolar lavage lymphocytosis, and, in selected cases, histology. The presence of fibrosis is associated with higher morbidity and mortality. Differentiating fibrotic HP from the idiopathic interstitial pneumonias can be a challenge. Furthermore, even in the context of a clear diagnosis of fibrotic HP, the disease behaviour can parallel that of idiopathic pulmonary fibrosis in a subgroup, with inexorable progression despite treatment. We review the current knowledge on the diagnosis, management, and prognosis of HP with particular focus on the fibrotic phenotype.

The diagnostic value of the bronchoalveolar lavage in interstitial lung diseases

Objective

Bronchoalveolar lavage (BAL) is a diagnostic tool often used during the management of interstitial lung diseases (ILD). However, its diagnostic value in discrimination between entities comprising the very heterogenous group of ILD, is still a controversial issue. The objective of our study is to assess the diagnostic value of BAL in the management of ILD, by comparing the cytological findings in BAL fluid among the different diseases of this group.

Methods

It was a retrospective, observational study of 151 patients between January 2012 and December 2015. BAL fluid cytology was performed to analyse the distribution of leucocytes population subsets in patients with ILD.

Results

The mean age was 52.78 years; 74.83% were women. The analysis of the following main groups of diseases was performed : sarcoïdosis (n = 30), idiopathic pulmonary fibrosis (IPF; n = 22), other idiopathic interstitial pneumonia (non specific interstitial pneumonia, cryptogenic organising pneumonia and respiratory bronchiolitis interstitial lung disease; n = 20) and connective tissue disease (n = 14).

Overall, out of 141 patients, 22% had sarcoïdosis, 15.6% had idiopathic pulmonary fibrosis (IPF), 14.18% had other idiopathic interstitial pneumonia (IIP) and 9.9% had connective tissue disease (CTD). Mixed alveolitis was common in the 4 groups, sarcoïdosis had higher proportion of lymphocytes and IPF had higher neutrophils count. However, there was no significant statistical difference of BAL cellular count among these diseases (p > 0.05). Also, the prevalence of studied diseases did not change with variation of BAL cellular count (p > 0.05).

Conclusion

Alone, the BAL cytological analysis has a limited value to provide substantial information that could lead to discriminate between diseases that form ILD. Thus, it must be always associated with other diagnostic methods.

Pulmonary Sarcoidosis

Sarcoidosis is a systemic disease, with lung involvement in almost all cases. Abnormal chest radiography is usually a key step for considering diagnosis. Lung impact is investigated through imaging; pulmonary function; and, when required, 6-minute walk test, cardiopulmonary exercise testing, or right heart catheterization. There is usually a reduction of lung volumes, and forced vital capacity is the most accurate parameter to reflect the impact of pulmonary sarcoidosis with or without pulmonary infiltration at imaging. Various evolution patterns have been described. Increased risk of death is associated with advanced pulmonary fibrosis or cor pulmonale, particularly in African American patients.

Occupational hypersensitivity pneumonitis: an EAACI position paper

The aim of this document was to provide a critical review of the current knowledge on hypersensitivity pneumonitis caused by the occupational environment and to propose practical guidance for the diagnosis and management of this condition. Occupational hypersensitivity pneumonitis (OHP) is an immunologic lung disease resulting from lymphocytic and frequently granulomatous inflammation of the peripheral airways, alveoli, and surrounding interstitial tissue which develops as the result of a non-IgE-mediated allergic reaction to a variety of organic materials or low molecular weight agents that are present in the workplace. The offending agents can be classified into six broad categories that include bacteria, fungi, animal proteins, plant proteins, low molecular weight chemicals, and metals. The diagnosis of OHP requires a multidisciplinary approach and relies on a combination of diagnostic tests to ascertain the work relatedness of the disease. Both the clinical and the occupational history are keys to the diagnosis and often will lead to the initial suspicion. Diagnostic criteria adapted to OHP are proposed. The cornerstone of treatment is early removal from exposure to the eliciting antigen, although the disease may show an adverse outcome even after avoidance of exposure to the causal agent.