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Aim: Transbronchial cryobiopsies are increasingly used for the diagnosis of interstitial lung disease (ILD), but there is a lack of published information on the features of specific ILD in cryobiopsies. Here we attempt to provide pathological guidelines for separating usual interstitial pneumonia (UIP) of idiopathic pulmonary fibrosis (IPF), fibrotic hypersensitivity pneumonitis (FHP) and connective tissue disease‐associated ILD (CTD–ILD) in cryobiopsies. Methods: We examined 120 cryobiopsies from patients with multidisciplinary discussion (MDD)‐established CTD–ILD and compared them to a prior series of 121 biopsies from patients with MDD‐established IPF or FHP. Results: A non‐specific interstitial pneumonia (NSIP) pattern alone was seen in 36 of 120 (30%) CTD–ILD, three of 83 (3.6%) FHP and two of 38 (5.2%) IPF cases, statistically favouring a diagnosis of CTD–ILD. The combination of NSIP + OP was present in 29 of 120 (24%) CTD–ILD, two of 83 (2.4%) FHP and none of 38 (0%) IPF cases, favouring a diagnosis of CTD–ILD. A UIP pattern, defined as fibroblast foci plus any of patchy old fibrosis/fibrosis with architectural distortion/honeycombing, was identified in 28 of 120 (23%) CTD–ILD, 45 of 83 (54%) FHP and 27 of 38 (71%) IPF cases and supported a diagnosis of FHP or IPF. The number of lymphoid aggregates/mm2 and fibroblast foci/mm2 was not different in IPF, CTD–ILD or FHP cases with a UIP pattern. Interstitial giant cells supported a diagnosis of FHP or CTD–ILD over IPF, but were infrequent. Conclusions: In the correct clinical/radiological context the pathological findings of NSIP, and particularly NSIP plus OP, favour a diagnosis of CTD–ILD in a cryobiopsy, but CTD–ILD with a UIP pattern, FHP with a UIP pattern and IPF generally cannot be distinguished. [ABSTRACT FROM AUTHOR]

Objective: This research primarily focuses on exploring the changes in intrapulmonary vascular volume (IPVV) in radiological patterns of usual interstitial pneumonia (UIP) associated with Type 2 Diabetes Mellitus (T2DM), thereby inferring the possible mechanisms of the co-occurrence of diabetes and UIP patterns. Methods: Thin-layer data were post-processed on the basis of high-resolution computed tomography (HRCT) and quantitatively assessed for IPVV. Changes in IPVV were compared between T2DM combined with UIP modality and T2DM non-UIP modality. Correlations between UIP patterns and various markers and confounders, including IPVV, were determined via logistic regression analysis. In this study, the potential of IPVV as a predictor for UIP presence was analysed through the application of subject operating characteristic curve analysis. Results: In patients with T2DM, the IPVV demonstrated smaller size in those with combined UIP patterns compared to T2DM patients without UIP patterns (164.4 ± 68.7 vs 202.9 ± 76.3 mL, P = 0.005). We detected a positive correlation between IPVV levels and several variables, including fasting plasma glucose (FPG) (r = 0.404, P < 0.0001), glycated hemoglobin (HbA1c) (r = 0.225, P = 0.022), serum uric acid (SUA) (r = 0.332, P = 0.0007) and HRCT scores (r = 0.288, P = 0.024). Conversely, negative correlations were noted with total cholesterol (TC) (r = –0.220, P = 0.028) and cystatin-C (Cys-C) (r = –0.215, P = 0.038). Multivariate logistic regression analysis identified independent associations between the presence of UIP and several factors: IPVV, age, smoking history, and FPG. In assessing the combined UIP pattern among T2DM patients, IPVV levels exhibited a sensitivity of 70.5% and a specificity of 58.5%, generating an AUC of 0.645. Conclusion: In individuals diagnosed with T2DM alongside UIP, a substantial decline in IPVV was documented. This diminution correlates with the presence of UIP, suggesting that IPVV may serve as a potent biomarker for detecting UIP patterns in individuals with T2DM. This may suggest that the mechanism behind the co-occurrence of T2DM with UIP patterns is attributed to alterations in the pulmonary microvasculature, potentially representing one of the vascular complications associated with diabetes. [ABSTRACT FROM AUTHOR]

Abstract Introduction The usual interstitial pneumonia (UIP) pattern, hallmark of idiopathic pulmonary fibrosis (IPF), may induce harmful local overdistension during mechanical ventilation given the juxtaposition of different tissue elasticities. Mechanotransduction, linking mechanical stress and strain to molecular pro-fibrotic pathways, likely contributes to fibrosis progression. Understanding the mechanical forces and aeration patterns in the lungs of IPF patients is crucial for unraveling potential mechanisms of disease progression. Quantitative lung computed tomography (CT) can accurately assess the air content of lung regions, thus informing on zonal distension. This study aims to investigate radiological evidence of lung over aeration in spontaneously breathing UIP patients compared to healthy controls during maximal inspiration. Methods Patients with IPF diagnosis referred to the Center for Rare Lung Diseases of the University Hospital of Modena (Italy) in the period 2020–2023 who underwent High Resolution Computed Tomography (HRCT) scans at residual volume (RV) and total lung capacity (TLC) using standardized protocols were retrospectively considered eligible. Patients with no signs of lung disease at HRCT performed with the same image acquisition protocol nor at pulmonary function test (PFTs) served as controls. Lung segmentation and quantitative analysis were performed using 3D Slicer software. Lung volumes were measured, and specific density thresholds defined over aerated and fibrotic regions. Comparison between over aerated lung at RV and TLC in the two groups and according to lung lobes was sought. Further, the correlation between aerated lung and the extent of fibrosis was assessed and compared at RV and TLC. Results IPF patients (N = 20) exhibited higher over aerated lung proportions than controls (N = 15) both at RV and TLC (4.5% vs. 0.7%, p

Rationale: Fibrotic hypersensitivity pneumonitis (FHP) is a debilitating interstitial lung disease driven by incompletely understood immune mechanisms. Objectives: To elucidate immune aberrations in FHP in single-cell resolution. Methods: Single-cell 5′ RNA sequencing was conducted on peripheral blood mononuclear cells and BAL cells obtained from 45 patients with FHP, 63 patients with idiopathic pulmonary fibrosis (IPF), 4 patients with nonfibrotic hypersensitivity pneumonitis, and 36 healthy control subjects in the United States and Mexico. Analyses included differential gene expression (Seurat), TF (transcription factor) activity imputation (DoRothEA-VIPER), and trajectory analyses (Monocle3 and Velocyto-scVelo-CellRank). Measurements and Main Results: Overall, 501,534 peripheral blood mononuclear cells from 110 patients and control subjects and 88,336 BAL cells from 19 patients were profiled. Compared with control samples, FHP has elevated classical monocytes (adjusted-P = 2.5 × 10−3) and is enriched in CCL3hi/CCL4hi and S100Ahi classical monocytes (adjusted-P < 2.2 × 10−16). Trajectory analyses demonstrate that S100Ahi classical monocytes differentiate into SPP1hi lung macrophages associated with fibrosis. Compared with both control subjects and IPF, cells from patients with FHP are significantly enriched in GZMhi cytotoxic T cells. These cells exhibit TF activities indicative of TGFβ and TNFα and NFκB pathways. These results are publicly available at . Conclusions: Single-cell transcriptomics of patients with FHP uncovered novel immune perturbations, including previously undescribed increases in GZMhi cytotoxic CD4+ and CD8+ T cells—reflecting this disease's unique inflammatory T cell–driven nature—as well as increased S100Ahi and CCL3hi/CCL4hi classical monocytes also observed in IPF. Both cell populations may guide the development of new biomarkers and therapeutic interventions. [ABSTRACT FROM AUTHOR]

Background: The presence of the rs35705950 variant in the MUC5B gene promoter is a critical genetic risk factor in idiopathic pulmonary fibrosis (IPF). It has been associated with usual interstitial pneumonia (UIP) in several interstitial lung diseases (ILDs). In antisynthetase syndrome (ASSD), most high-resolution computed tomography (HRCT) patterns are inflammatory, but up to 13% have UIP, leading to a worse prognosis. Methods: This single-center study included 60 patients with ASSD-ILD. We investigated whether carrying the MUC5B rs35705950 promoter variant was associated with UIP. To estimate the strength of the association between the genotype of the MUC5B rs35705950 promoter variant and the fibrotic pattern we used the odds ratio (cOR), and to assess the effect of confounding variables (age, evolution time, and sex), we performed a logistic regression to obtained the adjusted odds ratio (aOR). Results: The GT genotype of the MUC5B rs35705950 promoter variant is associated with up to a 4-fold increased risk of UIP (cOR 5.0, 95% CI 1.13–22.10), and the effect was even maintained after adjusting for potentially confounding variables such as sex, age, and time to progression (aOR 5.2, 95% CI 1.04–25.89). Conclusions: our study supports the role of MUC5B rs35705950 in ASSD-ILD with UIP. It reinforces that this polymorphism in our population could have a similar genetic basis to that already described in other ILDs that present predominantly fibrotic patterns. [ABSTRACT FROM AUTHOR]

Introduction: The usual interstitial pneumonia (UIP) pattern, hallmark of idiopathic pulmonary fibrosis (IPF), may induce harmful local overdistension during mechanical ventilation given the juxtaposition of different tissue elasticities. Mechanotransduction, linking mechanical stress and strain to molecular pro-fibrotic pathways, likely contributes to fibrosis progression. Understanding the mechanical forces and aeration patterns in the lungs of IPF patients is crucial for unraveling potential mechanisms of disease progression. Quantitative lung computed tomography (CT) can accurately assess the air content of lung regions, thus informing on zonal distension. This study aims to investigate radiological evidence of lung over aeration in spontaneously breathing UIP patients compared to healthy controls during maximal inspiration. Methods: Patients with IPF diagnosis referred to the Center for Rare Lung Diseases of the University Hospital of Modena (Italy) in the period 2020–2023 who underwent High Resolution Computed Tomography (HRCT) scans at residual volume (RV) and total lung capacity (TLC) using standardized protocols were retrospectively considered eligible. Patients with no signs of lung disease at HRCT performed with the same image acquisition protocol nor at pulmonary function test (PFTs) served as controls. Lung segmentation and quantitative analysis were performed using 3D Slicer software. Lung volumes were measured, and specific density thresholds defined over aerated and fibrotic regions. Comparison between over aerated lung at RV and TLC in the two groups and according to lung lobes was sought. Further, the correlation between aerated lung and the extent of fibrosis was assessed and compared at RV and TLC. Results: IPF patients (N = 20) exhibited higher over aerated lung proportions than controls (N = 15) both at RV and TLC (4.5% vs. 0.7%, p < 0.0001 and 13.8% vs. 7%, p < 0.0001 respectively). Over aeration increased significantly from RV to TLC in both groups, with no intergroup difference (p = 0.67). Sensitivity analysis revealed significant variations in over aerated lung areas among lobes when passing from RV to TLC with no difference within lobes (p = 0.28). Correlation between over aeration and fibrosis extent was moderate at RV (r = 0.62, p < 0.0001) and weak at TLC (r = 0.27, p = 0.01), being the two significantly different at interpolation analysis (p < 0.0001). Conclusions: This study provides the first evidence of radiological signs of lung over aeration in patients with UIP-pattern patients when passing from RV to TLC. These findings offer new insights into the complex interplay between mechanical forces, lung structure, and fibrosis and warrant larger and longitudinal investigations. [ABSTRACT FROM AUTHOR]

Abstract Background Recently, the diagnosis and follow-up of numerous pulmonary diseases such as pneumothorax, pneumonia, and pleural effusion were easily by use of conventional ultrasound, and the maximum usefulness of transthoracic ultrasonography (TUS) in pulmonary diseases especially diffuse parenchymal lung disease has not been detected yet. This study was conducted to determine the value of transthoracic ultrasonography in patients with interstitial lung disease (ILD). Moreover, the viable correlations of the ultrasound findings with the functional and radiological findings of ILDs had been assessed. Results TUS diagnosis was positive in 73 cases, there was a substantial variation between the two groups classified according to ultrasonographic diagnosis regarding age and smoking history (p = 0.003 and 0.013 respectively). All the patients with usual interstitial pneumonia (n = 42) and Indeterminate UIP (n = 49) had positive ultra-sonographic findings [p = 0.041 and 0.001 accordingly]. Regarding pulmonary function tests, there was a considerable variance between both groups regarding FVC, PEF, FEF25-75, FEV1/VC (p = 0.037, 0.029, 0.015, and 0.000 accordingly). The most positive US diagnosis areas were upper lateral, lateral basal, and interscapular areas. There was a weak negative correlation between TUS diagnosis and FVC [r = − 0.25, p = 0.026]. Conclusion We concluded the great significant value of TUS in the diagnosis and follow-up of patients with interstitial lung diseases. It had an extremely thoughtful role in the diagnosis of ILD by detection of multiple B-lines distribution emerging from pleura and extending in the entire lung surface. The use of TUS in early detection and follow-up of ILDs reduced the cost.

Rationale: Idiopathic pulmonary fibrosis (IPF) affects the subpleural lung but is considered to spare small airways. Micro–computed tomography (micro-CT) studies demonstrated small airway reduction in end-stage IPF explanted lungs, raising questions about small airway involvement in early-stage disease. Endobronchial optical coherence tomography (EB-OCT) is a volumetric imaging modality that detects microscopic features from subpleural to proximal airways. Objectives: In this study, EB-OCT was used to evaluate small airways in early IPF and control subjects in vivo. Methods: EB-OCT was performed in 12 subjects with IPF and 5 control subjects (matched by age, sex, smoking history, height, and body mass index). Subjects with IPF had early disease with mild restriction (FVC: 83.5% predicted), which was diagnosed per current guidelines and confirmed by surgical biopsy. EB-OCT volumetric imaging was acquired bronchoscopically in multiple, distinct, bilateral lung locations (total: 97 sites). IPF imaging sites were classified by severity into affected (all criteria for usual interstitial pneumonia present) and less affected (some but not all criteria for usual interstitial pneumonia present). Bronchiole count and small airway stereology metrics were measured for each EB-OCT imaging site. Measurements and Main Results: Compared with the number of bronchioles in control subjects (mean = 11.2/cm3; SD = 6.2), there was significant bronchiole reduction in subjects with IPF (42% loss; mean = 6.5/cm3; SD = 3.4; P = 0.0039), including in IPF affected (48% loss; mean: 5.8/cm3; SD: 2.8; P < 0.00001) and IPF less affected (33% loss; mean: 7.5/cm3; SD: 4.1; P = 0.024) sites. Stereology metrics showed that IPF-affected small airways were significantly larger, more distorted, and more irregular than in IPF-less affected sites and control subjects. IPF less affected and control airways were statistically indistinguishable for all stereology parameters (P = 0.36–1.0). Conclusions: EB-OCT demonstrated marked bronchiolar loss in early IPF (between 30% and 50%), even in areas minimally affected by disease, compared with matched control subjects. These findings support small airway disease as a feature of early IPF, providing novel insight into pathogenesis and potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Aims: Progressive pulmonary fibrosis (PPF) is a newly recognised clinical phenotype of interstitial lung diseases in the 2022 interstitial pulmonary fibrosis (IPF) guidelines. This category is based entirely on clinical and radiological factors, and the background histopathology is unknown. Our objective was to investigate the histopathological characteristics of PPF and to examine the correlation between usual interstitial pneumonia (UIP) and prognosis in this new disease type. We hypothesised that the presence of UIP‐like fibrosis predicts patients' survival in PPF cases. Methods and results: We selected 201 cases fulfilling the clinical criteria of PPF from case archives. Cases diagnosed as IPF by a multidisciplinary team were excluded. Whole slide images were evaluated by three pathologists who were blinded to clinical and radiological data. We measured areas of UIP‐like fibrosis and calculated what percentage of the total lesion area they occupied. The presence of focal UIP‐like fibrosis amounting to 10% or more of the lesion area was seen in 148 (73.6%), 168 (83.6%) and 165 (82.1%) cases for each pathologist, respectively. Agreement of the recognition of UIP‐like fibrosis in PPF cases was above κ = 0.6 between all pairs. Survival analysis showed that the presence of focal UIP‐like fibrosis correlated with worsened survival under all parameters tested (P < 0.001). Conclusions: The presence of UIP‐like fibrosis is a core pathological feature of clinical PPF, and its presence within diseased areas is associated with poorer prognosis. This study highlights the importance of considering the presence of focal UIP‐like fibrosis in the evaluation and management of PPF. [ABSTRACT FROM AUTHOR]

Background: Recently, the diagnosis and follow-up of numerous pulmonary diseases such as pneumothorax, pneumonia, and pleural effusion were easily by use of conventional ultrasound, and the maximum usefulness of transthoracic ultrasonography (TUS) in pulmonary diseases especially diffuse parenchymal lung disease has not been detected yet. This study was conducted to determine the value of transthoracic ultrasonography in patients with interstitial lung disease (ILD). Moreover, the viable correlations of the ultrasound findings with the functional and radiological findings of ILDs had been assessed. Results: TUS diagnosis was positive in 73 cases, there was a substantial variation between the two groups classified according to ultrasonographic diagnosis regarding age and smoking history (p = 0.003 and 0.013 respectively). All the patients with usual interstitial pneumonia (n = 42) and Indeterminate UIP (n = 49) had positive ultra-sonographic findings [p = 0.041 and 0.001 accordingly]. Regarding pulmonary function tests, there was a considerable variance between both groups regarding FVC, PEF, FEF25-75, FEV1/VC (p = 0.037, 0.029, 0.015, and 0.000 accordingly). The most positive US diagnosis areas were upper lateral, lateral basal, and interscapular areas. There was a weak negative correlation between TUS diagnosis and FVC [r = − 0.25, p = 0.026]. Conclusion: We concluded the great significant value of TUS in the diagnosis and follow-up of patients with interstitial lung diseases. It had an extremely thoughtful role in the diagnosis of ILD by detection of multiple B-lines distribution emerging from pleura and extending in the entire lung surface. The use of TUS in early detection and follow-up of ILDs reduced the cost. [ABSTRACT FROM AUTHOR]

Patients with acute exacerbation of lung fibrosis with usual interstitial pneumonia (EUIP) pattern are at increased risk for ventilator-induced lung injury (VILI) and mortality when exposed to mechanical ventilation (MV). Yet, lack of a mechanical model describing UIP-lung deformation during MV represents a research gap. Aim of this study was to develop a constitutive mathematical model for UIP-lung deformation during lung protective MV based on the stress–strain behavior and the specific elastance of patients with EUIP as compared to that of acute respiratory distress syndrome (ARDS) and healthy lung. Partitioned lung and chest wall mechanics were assessed for patients with EUIP and primary ARDS (1:1 matched based on body mass index and PaO2/FiO2 ratio) during a PEEP trial performed within 24 h from intubation. Patient's stress–strain curve and the lung specific elastance were computed and compared with those of healthy lungs, derived from literature. Respiratory mechanics were used to fit a novel mathematical model of the lung describing mechanical-inflation-induced lung parenchyma deformation, differentiating the contributions of elastin and collagen, the main components of lung extracellular matrix. Five patients with EUIP and 5 matched with primary ARDS were included and analyzed. Global strain was not different at low PEEP between the groups. Overall specific elastance was significantly higher in EUIP as compared to ARDS (28.9 [22.8–33.2] cmH2O versus 11.4 [10.3–14.6] cmH2O, respectively). Compared to ARDS and healthy lung, the stress/strain curve of EUIP showed a steeper increase, crossing the VILI threshold stress risk for strain values greater than 0.55. The contribution of elastin was prevalent at lower strains, while the contribution of collagen was prevalent at large strains. The stress/strain curve for collagen showed an upward shift passing from ARDS and healthy lungs to EUIP lungs. During MV, patients with EUIP showed different respiratory mechanics, stress–strain curve and specific elastance as compared to ARDS patients and healthy subjects and may experience VILI even when protective MV is applied. According to our mathematical model of lung deformation during mechanical inflation, the elastic response of UIP-lung is peculiar and different from ARDS. Our data suggest that patients with EUIP experience VILI with ventilatory setting that are lung-protective for patients with ARDS. [ABSTRACT FROM AUTHOR]

Interstitial lung disease (ILD) is a common pulmonary complication of rheumatoid arthritis (RA), causing significant morbidity and mortality. Optimal treatment for RA-ILD is not yet well defined. Reliable prognostic indicators are largely byproducts of prior ILD progression, including low or decreasing forced vital capacity and extensive or worsening fibrosis on imaging. In the absence of validated tools to predict treatment response, decisions about whether to initiate or augment treatment are instead based on clinical judgment. In general, treatment should be initiated in patients who are symptomatic, progressing, or at high risk of poor outcomes. Retrospective data suggest that mycophenolate mofetil, azathioprine, and rituximab are likely effective therapies for RA-ILD. Abatacept is also emerging as a potential first-line treatment option for patients with RA-ILD. Further, recent data demonstrate that immunosuppression may be beneficial even in patients with a usual interstitial pneumonia (UIP) pattern on imaging, suggesting that immunosuppression should be considered irrespective of imaging pattern. Recent randomized controlled trials have shown that antifibrotic medications, such as nintedanib and likely pirfenidone, slow forced vital capacity decline in RA-ILD. Consideration can be given to antifibrotic initiation in patients progressing despite immunosuppression, particularly in patients with a UIP pattern. Future research directions include developing tools to predict which patients will remain stable from patients who will progress, discriminating patients who will respond to treatment from nonresponders, and developing algorithms for starting immunosuppression, antifibrotics, or both as first-line therapies. [ABSTRACT FROM AUTHOR]

Rationale: Computed tomography (CT) enables noninvasive diagnosis of usual interstitial pneumonia (UIP), but enhanced image analyses are needed to overcome the limitations of visual assessment. Objectives: Apply multiple instance learning (MIL) to develop an explainable deep learning algorithm for prediction of UIP from CT and validate its performance in independent cohorts. Methods: We trained an MIL algorithm using a pooled dataset (n = 2,143) and tested it in three independent populations: data from a prior publication (n = 127), a single-institution clinical cohort (n = 239), and a national registry of patients with pulmonary fibrosis (n = 979). We tested UIP classification performance using receiver operating characteristic analysis, with histologic UIP as ground truth. Cox proportional hazards and linear mixed-effects models were used to examine associations between MIL predictions and survival or longitudinal FVC. Measurements and Main Results: In two cohorts with biopsy data, MIL improved accuracy for histologic UIP (area under the curve, 0.77 [n = 127] and 0.79 [n = 239]) compared with visual assessment (area under the curve, 0.65 and 0.71). In cohorts with survival data, MIL-UIP classifications were significant for mortality (n = 239, mortality to April 2021: unadjusted hazard ratio, 3.1; 95% confidence interval [CI], 1.96–4.91; P < 0.001; and n = 979, mortality to July 2022: unadjusted hazard ratio, 3.64; 95% CI, 2.66–4.97; P < 0.001). Individuals classified as UIP positive by the algorithm had a significantly greater annual decline in FVC than those classified as UIP negative (−88 ml/yr vs. −45 ml/yr; n = 979; P < 0.01), adjusting for extent of lung fibrosis. Conclusions: Computerized assessment using MIL identifies clinically significant features of UIP on CT. Such a method could improve confidence in radiologic assessment of patients with interstitial lung disease, potentially enabling earlier and more precise diagnosis. [ABSTRACT FROM AUTHOR]

Pulmonary diseases are among the most common complications of human immunodeficiency virus (HIV) infection, leading to significant morbidity and mortality in this population. As HIV-infected patients become older on successful antiretroviral therapy (ART), epidemiological data support a greater risk of noninfectious lung disorders associated with age, like chronic obstructive pulmonary disease (COPD), lung cancer, pulmonary hypertension, and a previously unrecognized increased incidence of pulmonary fibrosis. We present a 68-year-old male patient with features of interstitial lung disease and histopathological appearance of coexistence of organizing pneumonia (OP) and usual interstitial pneumonia (UIP). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Idiopathic pulmonary fibrosis is the most prevalent form of interstitial lung disease, which presents as usual interstitial pneumonia on histopathology and imaging. It leads to significant lung scarring, damage, and fibrosis and is associated with a high degree of mortality, repeated hospital admissions, and oxygen dependence. Many complications are associated with idiopathic pulmonary fibrosis, which further increases the morbidity of patients. High-resolution computed tomography chest is the imaging modality of choice for usual interstitial pneumonia tracking its progression, evaluating treatment response, and detecting potential complications. Methods: This descriptive cross-sectional study was approved by the institutional ethics committee (reference number: IEC INT/2023/Study-1256). Departmental computed tomography report database from November 2017 to June 2018 was reviewed and scans with imaging features consistent with the ‘usual interstitial pneumonia’ pattern were identified. Total sampling method was used and two independent radiologists, blinded to the patient's clinical information, reviewed the high- resolution computed tomography chest scans to assess for imaging features of usual interstitial pneumonia and associated complications. Results: There were 65 patients reported as unusual interstitial pneumonia pattern. Emphysema and pneumothorax were identified in four (6.15%) and one (1.53%) scans, respectively. Two (3.08%) scans showed features of pulmonary arterial hypertension. Ten (15.38%) scans exhibited findings consistent with co-existent or superimposed pulmonary infection. Additionally, features of lung malignancy were identified in high-resolution computed tomography scans of five (7.69%) patients. Conclusions: This study sheds light on imaging manifestations of usual interstitial pneumoniacomplications, aiding radiologists and pulmonologists in earlier diagnosis and improved patient management.

The inhalation of hard metal may produce various respiratory manifestations including upper respiratory tract irritation, asthma, hypersensitivity pneumonia (HP), and a particular form of interstitial lung disease. Co is the main cause of the adverse health outcomes in hard metal workers. A particular form of interstitial lung disease, called hard metal lung disease (HMLD) includes giant cell interstitial pneumonia (GIP) and pulmonary fibrosis. Clinical and radiologic features of GIP resemble those of HP. In patients with HMLD, pulmonary fibrosis showing usual interstitial pneumonia (UIP) pattern is found. It is unclear that GIP progresses to severe fibrosis showing UIP pattern if the exposure to hard metal is not stopped. Follow-up CT scans suggest that GIP dose not progress to fibrosis showing UIP pattern. GIP and hard metal induced pulmonary fibrosis may be two different representations resulting from exposure to hard metal. Under current diagnostic criteria, both GIP and pulmonary fibrosis with UIP pattern are included.Cobalt exposure can occur inhalation, ingestion, and dermal routes. There is knowledge regarding the importance of cobalt ions skin absorption in relation to absorption via the respiratory tract in cobalt exposure. Co ions skin absorption can be considered as the reason that cases of hard metal workers’ asthma and HMLD occur more often at the wet area than at the dry area.

Histopathologic criteria of usual interstitial pneumonia (UIP)/idiopathic pulmonary fibrosis (IPF) were defined over the years and endorsed by leading organizations decades after Dr. Averill A. Liebow first coined the term UIP in the 1960s as a distinct pathologic pattern of fibrotic interstitial lung disease. Novel technology and recent research on interstitial lung diseases with genetic component shed light on molecular pathogenesis of UIP/IPF. Two antifibrotic agents introduced in the mid-2010s opened a new era of therapeutic approaches to UIP/IPF, albeit contentious issues regarding their efficacy, side effects, and costs. Recently, the concept of progressive pulmonary fibrosis was introduced to acknowledge additional types of progressive fibrosing interstitial lung diseases with the clinical and pathologic phenotypes comparable to those of UIP/IPF. Likewise, some authors have proposed a paradigm shift by considering UIP as a stand-alone diagnostic entity to encompass other fibrosing interstitial lung diseases that manifest a relentless progression as in IPF. These trends signal a pendulum moving toward the tendency of lumping diagnoses, which poses a risk of obscuring potentially important information crucial to both clinical and research purposes. Recent advances in whole slide imaging for digital pathology and artificial intelligence technology could offer an unprecedented opportunity to enhance histopathologic evaluation of interstitial lung diseases. However, current clinical practice trends of moving away from surgical lung biopsies in interstitial lung disease patients may become a limiting factor in this endeavor as it would be difficult to build a large histopathologic database with correlative clinical data required for artificial intelligence models.

Background: Interstitial lung disease (ILD) also called as diffuse parenchymal lung diseases (DPLD) are “a diverse group of pulmonary infiltrations which result in disruption of the distal lung parenchyma characterized by both inflammation and fibrosis of lung parenchyma and is associated with wide variety of clinical situations.” The understanding of etiology and the underlying CT pattern is helpful in diagnosis, treatment initiation, assessment of response, disease prognosis, and setting up appropriate interventions to improve survival and the quality of life. Methods: A prospective observational analysis of “Radiological and Etiological patterns” in patients presenting with features of the ILD in a tertiary care hospital in South India. Results: The study consisted of 104 patients, with mean age group of 48.03 years, with female 54% of the study population. The commonest high-resolution computed tomography (HRCT) thorax pattern was usual interstitial pneumonia (UIP) (n = 52, 50%). The commonest etiology of the ILD was connective tissue disorders (CTD) (n = 59, 56.73%). Most common CTD was systemic sclerosis (n = 23, 22.11%) and rheumatoid arthritis (n = 20, 19.23%). Second most common etiology was Idiopathic Pulmonary Fibrosis (IPF) (n=15, 14.42%). The UIP pattern was observed in 59.32% patients with CTD-ILD (n = 35) and in 100% patients with the IPF. Conclusion: Connective tissue disorders was the commonest etiology (n = 59, 56.73%), followed by idiopathic etiology (n = 22, 21.15%). Unlike other studies where NSIP pattern was the commonest pattern in CTD-ILD, it was observed in our study that UIP pattern was the most common CT pattern (n = 52, 50%) in connective tissue disorders as well as other etiology of the ILDs.

Abstract Usual Interstitial Pneumonia (UIP) is characterized by progression of lung parenchyma that may be observed in various autoimmune rheumatic diseases (ARDs), including rheumatoid arthritis and connective tissue diseases. From a diagnostic point of view, a UIP pattern related to ARDs may display imaging and pathological features able to distinguish it from that related to IPF, such as the “straight-edge” sign at HRCT and lymphoplasmacytic infiltrates at histologic specimens. Multidisciplinary approach (MDD), involving at least pulmonologist, rheumatologist and radiologist, is fundamental in the differential diagnosis process, but MDD is also required in the evaluation of severity, progression and response to treatment, that is based on the combination of changes in symptoms, pulmonary function trends, and, in selected patients, serial CT evaluation. Differently from IPF, in patients with ARDs both functional evaluation and patient-reported outcomes may be affected by systemic involvement and comorbidities, including musculoskeletal manifestations of disease. Finally, in regards to pharmacological treatment, immunosuppressants have been considered the cornerstone of therapy, despite the lack of solid evidence in most cases; recently, antifibrotic drugs were also proposed for the treatment of progressive fibrosing ILDs other than IPF. In ARD-ILD, the therapeutic choice should balance the need for the control of systemic and lung involvements with the risk of adverse events from multi-morbidities and -therapies. Purpose of this review is to summarize the definition, the radiological and morphological features of the UIP pattern in ARDs, together with risk factors, diagnostic criteria, prognostic evaluation, monitoring and management approaches of the UIP-ARDs.

Background. Diagnosis of hypersensitivity pneumonitis (HP) using high-resolution computed tomography (HRCT) is not an easy task. The most difficult aspects of the disease include differential diagnosis of its fibrotic (fHP) and non-fibrotic (nfHP) phenotypes, as well as their differentiation from usual interstitial pneumonia (UIP) in idiopathic pulmonary fibrosis. The determination of fibrous changes at an early stage of development can significantly accelerate the beginning of antifibrotic therapy and improve the prognosis.Objective: to identify key HRCT signs for reliable differentiation of fHP and nfHP, to carry out differential diagnostics between fHP and UIP.Material and methods. The data of 73 patients with morphologically verified HP, in whom HRCT had been performed, were retrospectively analysed. In 21 patients, nfHP was determined, and in 52 patients fHP was identified. The comparison group consisted of 24 patients with a typical radiological UIP pattern. The analysis of the changes detected during HRCT was carried out by qualitative and semi-quantitative methods. The significance of qualitative differences in a sign manifestation was assessed by Fisher’s exact test, semi-quantitative differences were evaluated using Mann–Whitney test.Results. The results of the study allow to assume, that the presence and degree of manifestation of certain HRCT signs significantly differ between the selected groups of patients in qualitative and/or semi-quantitative terms. In cases of НP, the distribution of changes was mostly uniform and diffuse, with no clear predominance in certain lobes. In UIP, diffuse craniocaudal distribution took place, and in the axial plane, the changes were mainly subpleural in nature.Conclusion. Based on the results of the study, it can be assumed that fHP significantly differs from nfHP in such features as the presence and degree of manifestation of ground glass and honeycombing symptoms, reticular changes and traction bronchiectases. When comparing the fHP and UIP groups, the distinctive signs of fHP were centrilobular nodules, mosaic pattern, as well as diffuse axial sign distribution.

Abstract Risk factors of severe coronavirus disease 2019 (COVID-19) have been previously reported; however, histological risk factors have not been defined thus far. The aim of this study was to clarify subclinical hidden interstitial lung disease (ILD) as a risk factor of severe pneumonia associated with COVID-19. We carefully examined autopsied lungs and chest computed tomography scanning (CT) images from patients with COVID-19 for interstitial lesions and then analyzed their relationship with disease severity. Among the autopsy series, subclinical ILD was found in 13/27 cases (48%) in the COVID-19 group, and in contrast, 8/65 (12%) in the control autopsy group (p = 0.0006; Fisher’s exact test). We reviewed CT images from the COVID-19 autopsy cases and verified that subclinical ILD was histologically detectable in the CT images. Then, we retrospectively examined CT images from another series of COVID-19 cases in the Yokohama, Japan area between February–August 2020 for interstitial lesions and analyzed the relationship to the severity of COVID-19 pneumonia. Interstitial lesion was more frequently found in the group with the moderate II/severe disease than in the moderate I/mild disease (severity was evaluated according to the COVID-19 severity classification system of the Ministry of Health, Labor, and Welfare [Japan]) (moderate II/severe, 11/15, 73.3% versus moderate I/mild, 108/245, 44.1%; Fisher exact test, p = 0.0333). In conclusion, it was suggested that subclinical ILD could be an important risk factor for severe COVID-19 pneumonia. A benefit of these findings could be the development of a risk assessment system using high resolution CT images for fatal COVID-19 pneumonia.

Background Decisions on the management of interstitial lung diseases (ILD) and prognostication require an accurate diagnosis. It has been proposed that multidisciplinary team (MDT) meetings for ILD (ILD-MDT) improve these decisions in challenging cases of ILD. However, most studies in this field have been based on the decisions of individual clinicians and there are few reports on the outcomes of the ILD-MDT approach. We therefore describe the experience of the ILD-MDT meetings at our institution.

Rationale: Radiologic pattern has been shown to predict survival in patients with fibrosing interstitial lung disease. The additional prognostic value of fibrosis extent by quantitative computed tomography (CT) is unknown. Objectives: We hypothesized that fibrosis extent provides information beyond visually assessed CT pattern that is useful for outcome prediction. Methods: We performed a retrospective analysis of chest CT, demographics, longitudinal pulmonary function, and transplantation-free survival among participants in the Pulmonary Fibrosis Foundation Patient Registry. CT pattern was classified visually according to the 2018 usual interstitial pneumonia criteria. Extent of fibrosis was objectively quantified using data-driven textural analysis. We used Kaplan-Meier plots and Cox proportional hazards and linear mixed-effects models to evaluate the relationships between CT-derived metrics and outcomes. Results: Visual assessment and quantitative analysis were performed on 979 enrollment CT scans. Linear mixed-effect modeling showed that greater baseline fibrosis extent was significantly associated with the annual rate of decline in forced vital capacity. In multivariable models that included CT pattern and fibrosis extent, quantitative fibrosis extent was strongly associated with transplantation-free survival independent of CT pattern (hazard ratio, 1.04; 95% confidence interval, 1.04--1.05; P,0.001; C statistic = 0.73). Conclusions: The extent of lung fibrosis by quantitative CT is a strong predictor of physiologic progression and survival, independent of visually assessed CT pattern. [ABSTRACT FROM AUTHOR]

Background: We proposed the term "UIPAF" to define patients with Usual Interstitial Pneumonia (UIP) associated with only one domain of the classification called "Interstitial Pneumonia with Autoimmune Features" (IPAF). The objective of this study was to evaluate the clinical presentation and prognosis of UIPAF patients, compared with two cohorts, composed of IPAF and idiopathic pulmonary fibrosis (IPF) patients, respectively. Methods: The patients were enrolled as IPAF, UIPAF, or IPF based on clinical, serological, and radiological data and evaluated by a multidisciplinary team. Results: We enrolled 110 patients with IPF, 69 UIPAF, and 123 IPAF subjects. UIPAF patients were similar to IPAF regarding autoimmune features, except for the prevalence of Rheumatoid Factor in UIPAF and anti-SSA in IPAF. A similar proportion of the two cohorts progressed toward a specific autoimmune disease (SAD), with differences in the kind of SAD developed. The real-life management and prognosis of UIPAF patients proved to be almost identical to IPF. Conclusions: UIPAF shared with IPAF similar autoimmune features, suggesting the opportunity to be considered IPAF, excluding the morphological domain by the classification. However, the real-life management and prognosis of UIPAF are similar to IPF. These data suggest a possible modification in the therapeutic management of UIPAF. [ABSTRACT FROM AUTHOR]

• Treatment of rheumatoid arthritis-interstitial lung disease is challenging. • Abatacept seems to be an effective therapy, regardless of the radiological pattern. • Early administration of abatacept may prevent progression of the disease. To compare the effectiveness of abatacept (ABA) in Rheumatoid Arthritis-associated Interstitial Lung Disease (RA-ILD) according to the radiological patterns of usual (UIP) or non-specific interstitial pneumonia (NSIP). From an observational longitudinal multicentre study of 263 RA-ILD patients treated with ABA, those with UIP or NSIP were selected. Lung function, chest high resolution computerised tomography (HRCT) and dyspnoea were recorded and compared in both groups from baseline to the end of follow-up (progression definitions: improvement or worsening >10% of FVC or DLCO, changes in HRCT extension and 1-point change in the mMRC scale, respectively). Differences between final and baseline visits were calculated as the average difference (95% CI) through mixed effects models regression. We studied 190 patients with UIP (n=106) and NSIP (n=84). General features were similar in both groups except for older age, positive rheumatoid factor, and previous sulfasalazine therapy, which were more frequent in patients with UIP. ILD duration up to ABA initiation was relatively short: median 16 [4-50] and 11 [2-36] months (p=0.36) in UIP and NSIP, respectively. Mean baseline FVC and DLCO were 82% and 63% in UIP and 89% and 65% in NSIP, respectively. Both parameters remained stable during 24 months with ABA. HRCT lesions and dyspnoea improved/stabilized in 73.1% and 90.5% and 72.9% and 94.6% of UIP and NSIP patterns, respectively. ABA seems equally effective in stabilizing dyspnoea, lung function and radiological impairment in both UIP and NSIP patterns of RA-ILD. Early administration of ABA may prevent RA-ILD progression, regardless of the radiological pattern. [ABSTRACT FROM AUTHOR]

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Usual Interstitial Pneumonia (UIP) is characterized by progression of lung parenchyma that may be observed in various autoimmune rheumatic diseases (ARDs), including rheumatoid arthritis and connective tissue diseases. From a diagnostic point of view, a UIP pattern related to ARDs may display imaging and pathological features able to distinguish it from that related to IPF, such as the "straight-edge" sign at HRCT and lymphoplasmacytic infiltrates at histologic specimens. Multidisciplinary approach (MDD), involving at least pulmonologist, rheumatologist and radiologist, is fundamental in the differential diagnosis process, but MDD is also required in the evaluation of severity, progression and response to treatment, that is based on the combination of changes in symptoms, pulmonary function trends, and, in selected patients, serial CT evaluation. Differently from IPF, in patients with ARDs both functional evaluation and patient-reported outcomes may be affected by systemic involvement and comorbidities, including musculoskeletal manifestations of disease. Finally, in regards to pharmacological treatment, immunosuppressants have been considered the cornerstone of therapy, despite the lack of solid evidence in most cases; recently, antifibrotic drugs were also proposed for the treatment of progressive fibrosing ILDs other than IPF. In ARD-ILD, the therapeutic choice should balance the need for the control of systemic and lung involvements with the risk of adverse events from multi-morbidities and -therapies. Purpose of this review is to summarize the definition, the radiological and morphological features of the UIP pattern in ARDs, together with risk factors, diagnostic criteria, prognostic evaluation, monitoring and management approaches of the UIP-ARDs. [ABSTRACT FROM AUTHOR]

Few biomarkers distinguish connective tissue disease-associated interstitial lung disease (CTD-ILD) from idiopathic pulmonary fibrosis (IPF). Latent transforming growth factor-β binding protein-2 (LTBP2), a secreted extracellular matrix protein, is involved in pulmonary fibrosis. However, the role of LTBP2 in differentially diagnosing CTD-ILD and IPF is unclear. In this study, enzyme-linked immunosorbent assays quantified plasma LTBP2 concentrations in 200 individuals (35 healthy controls, 42 CTD patients without ILD, 89 CTD-ILD patients, and 34 IPF patients). CTD-ILD and IPF were further classified based on chest imaging pattern and pulmonary function test results. Plasma LTBP2 levels were significantly elevated in the IPF group compared with the CTD-ILD group. ROC analysis further suggested the possible value of LTBP2 in differentially diagnosing CTD-ILD and IPF. Additionally, CTD-ILD patients with progressive lung fibrosis had higher plasma LTBP2 concentrations than those who did not. Similarly, patients with IPF developing acute exacerbation showed higher plasma LTBP2 levels than those with stable IPF. This is the first study showing that LTBP2 was closely associated with the usual interstitial pneumonia (UIP) pattern in rheumatoid arthritis-associated ILD (RA-ILD). Moreover, the optimal cutoff values of LTBP2 for distinguishing IPF from CTD-UIP/RA-UIP were 33.75 and 38.33 ng/mL with an AUC of 0.682 and 0.681, respectively. Our findings suggest that plasma LTBP2 levels may differentially diagnose CTD-ILD and IPF, and assess their fibrotic activity. Additionally, clinical LTBP2 evaluation may be a great aid to identifying the presence of the UIP pattern in RA-ILD and to discriminating IPF from CTD-UIP, particularly RA-UIP. [ABSTRACT FROM AUTHOR]

Clinical practice guidelines separately describe radiologic patterns of usual interstitial pneumonia (UIP) and fibrotic hypersensitivity pneumonitis (fHP), without direction on whether or how to apply these approaches concurrently within a single patient. How can we integrate guideline-defined radiologic patterns to diagnose interstitial lung disease (ILD) and what are the pitfalls associated with described patterns that require reassessment in future guidelines? Patients from the Canadian Registry for Pulmonary Fibrosis underwent detailed reevaluation in standardized multidisciplinary discussion. CT scan features were quantified by chest radiologists masked to clinical data, and guideline-defined patterns were assigned. Clinical data then were provided to the radiologist and an ILD clinician, who jointly determined the leading diagnosis. Clinical-radiologic diagnosis in 1,593 patients was idiopathic pulmonary fibrosis (IPF) in 26%, fHP in 12%, connective tissue disease-associated ILD (CTD-ILD) in 34%, idiopathic pneumonia with autoimmune features in 12%, and unclassifiable ILD in 10%. Typical and probable UIP patterns corresponded to a diagnosis of IPF in 66% and 57% of patients, respectively. Typical fHP pattern corresponded to an fHP clinical diagnosis in 65% of patients, whereas compatible fHP was nonspecific and associated with CTD-ILD or IPAF in 48% of patients. No pattern ruled out CTD-ILD. Gas trapping affecting > 5% of lung parenchyma on expiratory imaging was an important feature broadly separating compatible and typical fHP from other patterns (sensitivity, 0.77; specificity, 0.91). An integrated approach to guideline-defined UIP and fHP patterns is feasible and supports > 5% gas trapping as an important branch point. Typical or probable UIP and typical fHP patterns have moderate predictive values for a corresponding diagnosis of IPF and fHP, although occasionally confounded by CTD-ILD; compatible fHP is nonspecific. [ABSTRACT FROM AUTHOR]

Abstract Background Rheumatoid arthritis (RA) is often accompanied by a common extra-articular manifestation known as RA-related usual interstitial pneumonia (RA-UIP), which is associated with a poor prognosis. However, the mechanism remains unclear. To identify potential mechanisms, we conducted bioinformatics analysis based on high-throughput sequencing of the Gene Expression Omnibus (GEO) database. Results Weighted gene co-expression network analysis (WGCNA) analysis identified 2 RA-positive related modules and 4 idiopathic pulmonary fibrosis (IPF)-positive related modules. A total of 553 overlapped differentially expressed genes (DEG) were obtained, of which 144 in the above modules were further analyzed. The biological process of “oxidative phosphorylation” was found to be the most relevant with both RA and IPF. Additionally, 498 up-regulated genes in lung tissues of RA-UIP were screened out and enriched by 7 clusters, of which 3 were closely related to immune regulation. The analysis of immune infiltration showed a characteristic distribution of peripheral immune cells in RA-UIP, compared with IPF-UIP in lung tissues. Conclusions These results describe the complex molecular and functional landscape of RA-UIP, which will help illustrate the molecular pathological mechanism of RA-UIP and identify new biomarkers and therapeutic targets for RA-UIP in the future.

Abstract Background Along with the improvement of lung cancer screening implementation, the identification of interstitial lung abnormality (ILA) is increasing. Currently, there is a limited description of the oncogenic status and ILA subtypes among newly diagnosed non‐small cell lung cancer (NSCLC) patients with ILA in the Chinese population. This study aimed to investigate the prevalence, characteristics, oncogenic status and factors associated with overall survival (OS) among NSCLC patients with ILA. Methods A total of 765 newly diagnosed NSCLC cases at our hospital were reviewed and ILA was diagnosed according to the criteria of the Fleischner Society. The characteristics, clinical pathological features and OS of NSCLC patients with ILA were retrospectively analyzed. Results Of the 765 patients included in the study, 101 (13.2%) cases experienced ILA at the time of NSCLC diagnosis. Multivariate analysis revealed that ILA was more likely to be detected in NSCLC patients who were age ≥60 (OR 2.404, p = 0.001), male gender (OR 2.476, p = 0.004), and EGFR wild‐type (OR 2.035, p = 0.007). Additionally, according to the multivariate Cox model, the presence of ILA in NSCLC patients was significantly associated with a shorter OS period than those without ILA (751 days vs. 445 days, HR 0.6, p = 0.001). Following analysis, it was determined that OS in patients with usual interstitial pneumonia (UIP) was shorter than in those without UIP (HR 1.82, p = 0.037). Conclusion ILA is a common comorbidity among newly diagnosed NSCLC patients. We found that patients with EGFR wild‐type NSCLC were more likely to develop ILA. The presence of ILA, especially UIP, was significantly associated with poor NSCLC prognosis.

Lung disease is the second most frequent extra articular manifestation in rheumatoid arthritis (RA) patients. It can be present in up to 80% RA cases and represents a major cause of morbidity and mortality. One of the most common types of lung involvement in RA patients is the interstitial lung disease (ILD). Computed tomography studies show evidence of ILD in a large proportion of patients with RA (over 50% in some studies) and it can be clinically symptomatic in 5% of cases. The CT aspect classifies four forms of ILD, listed in order of frequency: usual interstitial pneumonia (UIP) - the most common form, non-specific interstitial pneumonia (NSIP), organizing pneumonia (OP) and diffuse alveolar damage (DAD) which is the least common form. We present a long-standing case of rheumatoid arthritis overlapping systemic sclerosis with interstitial lung disease.

Abstract Background The distinction between hypersensitivity pneumonitis (HP) and idiopathic pulmonary fibrosis (IPF) was thought to be important due to the difference in mortality between the conditions as well as the response to treatment. However, recent work suggests that the clinical diagnosis may matter less than certain radiographic features, namely usual interstitial pneumonia (UIP) pattern. The purpose of this study is to evaluate whether radiographic honeycombing is more predictive of transplant-free survival (TFS) than other clinical, radiographic, or histologic findings that distinguish HP from IPF in the current guidelines and to evaluate the impact of radiographic honeycombing on the efficacy of immunosuppression in fibrotic HP. Methods We retrospectively identified IPF and fibrotic HP patients evaluated between 2003 and 2019. Univariable and multivariable logistic regression was performed for patients with fibrotic HP and IPF to evaluate TFS. To assess the impact of treatment with immunosuppression on TFS in fibrotic HP, a cox proportional hazard model adjusted for known predictors of survival in HP including age, gender, and baseline pulmonary function testing results was constructed, and p-interaction for the presence of honeycombing on high resolution computed tomography and use of immunosuppression was calculated. Results Our cohort included 178 with IPF and 198 with fibrotic HP. In a multivariable analysis, the presence of honeycombing had a greater impact on the TFS than the diagnosis of HP vs. IPF. Among the criteria used in the HP diagnostic guidelines, only typical HP scan impacted survival in a multivariable model, while identification of antigen and surgical lung biopsy findings had no impact on survival. We identified a trend toward worse survival on immunosuppression in those with HP with radiographic honeycombing. Conclusion Our data suggests that honeycombing and baseline pulmonary function testing have a greater impact on TFS than the clinical diagnosis of IPF vs. fibrotic HP and that radiographic honeycombing is a predictor of poor TFS in fibrotic HP. We suggest that invasive diagnostic testing including surgical lung biopsy may not be useful in predicting mortality in HP patients with honeycombing and may potentially increase risk of immunosuppression.

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. [ABSTRACT FROM AUTHOR]

Risk factors of severe coronavirus disease 2019 (COVID-19) have been previously reported; however, histological risk factors have not been defined thus far. The aim of this study was to clarify subclinical hidden interstitial lung disease (ILD) as a risk factor of severe pneumonia associated with COVID-19. We carefully examined autopsied lungs and chest computed tomography scanning (CT) images from patients with COVID-19 for interstitial lesions and then analyzed their relationship with disease severity. Among the autopsy series, subclinical ILD was found in 13/27 cases (48%) in the COVID-19 group, and in contrast, 8/65 (12%) in the control autopsy group (p = 0.0006; Fisher's exact test). We reviewed CT images from the COVID-19 autopsy cases and verified that subclinical ILD was histologically detectable in the CT images. Then, we retrospectively examined CT images from another series of COVID-19 cases in the Yokohama, Japan area between February–August 2020 for interstitial lesions and analyzed the relationship to the severity of COVID-19 pneumonia. Interstitial lesion was more frequently found in the group with the moderate II/severe disease than in the moderate I/mild disease (severity was evaluated according to the COVID-19 severity classification system of the Ministry of Health, Labor, and Welfare [Japan]) (moderate II/severe, 11/15, 73.3% versus moderate I/mild, 108/245, 44.1%; Fisher exact test, p = 0.0333). In conclusion, it was suggested that subclinical ILD could be an important risk factor for severe COVID-19 pneumonia. A benefit of these findings could be the development of a risk assessment system using high resolution CT images for fatal COVID-19 pneumonia. [ABSTRACT FROM AUTHOR]