Search

Background: The pathophysiology of refractory asthma is not well understood; thus, treatment modalities are not targeted to specific phenotypes but rather to a broad-based treatment approach. The objective of this study was to develop refractory asthma phenotypes based on bronchoscopic evaluation and to develop from this information specific, directed, personalized therapy.Methods: Fifty-eight patients with difficult-to-treat (refractory) asthma were characterized by the use of fiber-optic bronchoscopy with visual scoring systems of the upper and lower airways as well as with BAL, endobronchial biopsy, and brush. Response to changes in therapy was evaluated by changes in the Asthma Control Test and pulmonary function.Results: Five mutually exclusive phenotypes were formulated based on bronchoscopic evaluation: gastroesophageal reflux, subacute bacterial infection, tissue eosinophilia, combination, and nonspecific. Specific directed therapy yielded a significant improvement in the Asthma Control Test and pulmonary function for the entire group as well as for each defined subgroup except for the nonspecific group. Of interest, visual scoring of the supraglottic abnormalities identified 34 of 35 patients with gastroesophageal reflux and may give a better insight into asthmatic problems associated with chronic proximal reflux than standard testing.Conclusions: Bronchoscopic evaluation of the upper and lower airways can provide important information toward characterizing refractory asthma so as to better individualize therapeutic options and improve asthma control and lung function in patients with difficult-to-treat asthma. [ABSTRACT FROM AUTHOR]

Rationale: The critical innate immune mechanisms that regulate granulomatous inflammation in sarcoidosis are unknown. Because the granuloma-inducing component of sarcoidosis tissues has physicochemical properties similar to those of amyloid fibrils, we hypothesized that host proteins capable of forming poorly soluble aggregates or amyloid regulate inflammation in sarcoidosis.Objectives: To determine the role of the amyloid precursor protein, serum amyloid A, as an innate regulator of granulomatous inflammation in sarcoidosis.Methods: Serum amyloid A expression was determined by immunohistochemistry in sarcoidosis and control tissues and by ELISA. The effect of serum amyloid A on nuclear factor (NF)-kappaB induction, cytokine expression, and Toll-like receptor-2 stimulation was determined with transformed human cell lines and bronchoalveolar lavage cells from patients with sarcoidosis. The effects of serum amyloid A on regulating helper T cell type 1 (Th1) granulomatous inflammation were determined in experimental models of sarcoidosis, using Mycobacterium tuberculosis catalase-peroxidase.Measurements and Main Results: We found that the intensity of expression and distribution of serum amyloid A within sarcoidosis granulomas was unlike that in many other granulomatous diseases. Serum amyloid A localized to macrophages and giant cells within sarcoidosis granulomas but correlated with CD3(+) lymphocytes, linking expression to local Th1 responses. Serum amyloid A activated NF-kappaB in Toll-like receptor-2-expressing human cell lines; regulated experimental Th1-mediated granulomatous inflammation through IFN-gamma, tumor necrosis factor, IL-10, and Toll-like receptor-2; and stimulated production of tumor necrosis factor, IL-10, and IL-18 in lung cells from patients with sarcoidosis, effects inhibited by blocking Toll-like receptor-2.Conclusions: Serum amyloid A is a constituent and innate regulator of granulomatous inflammation in sarcoidosis through Toll-like receptor-2, providing a mechanism for chronic disease and new therapeutic targets. [ABSTRACT FROM AUTHOR]

Purposes: To describe a cohort of patients who presented with interstitial lung disease (ILD) of unknown cause, features of primary Sjögren syndrome (pSS), and a positive minor salivary gland biopsy (MSGB).Methods: Thirty-eight patients with ILD evaluated at our center underwent an MSGB to confirm a diagnosis of pSS. All of the samples were reviewed by pathologists experienced in the evaluation of salivary gland histology. We defined a positive MSGB finding as a lymphocyte focus score of >1.Results: At presentation, all patients had ILD, and symptoms of cough and dyspnea. None had a definable connective tissue disease (CTD) or known cause for their ILD. Thirteen patients (34%) had positive MSGB findings. Of these, the median age was 61 years (age range, 33 to 75 years); 7 patients (54%) were women; 8 patients (62%) had a smoking history; and 10 patients (77%) had sicca symptoms. In all patients, a thoracic high-resolution CT scan evaluation demonstrated bibasilar, peripheral-predominant, ground-glass, and reticular opacities. Four patients (31%) were negative for both antinuclear autoantibody (ANA) and rheumatoid factor (RF) autoantibody, and three patients (23%) were negative for ANA, RF, Sjögren syndrome (SS)-A, and SS-B autoantibodies. No patients experienced any complications from the MSGB. The identification of underlying pSS did not affect the management of ILD in these patients.Conclusions: Confirming a diagnosis of pSS-related ILD by performing MSGB allows for a more precise CTD classification. This study provides evidence that CTD may exist subclinically, and longitudinal studies are needed to determine whether identifying occult CTD impacts on management, longitudinal changes in lung function, or survival. [ABSTRACT FROM AUTHOR]

Background: It is now recognized that a significant portion of patients with idiopathic pulmonary fibrosis (IPF) can have sudden and rapid deteriorations in disease course that cannot be explained by infection, heart failure, or thromboembolic disease. These events are often fatal and have been termed acute exacerbations (AEs) of underlying disease. While best described in patients with IPF, they have also been reported in patients with other forms of interstitial lung disease. We sought to determine if this same phenomenon occurs in patients with hypersensitivity pneumonitis (HP).Methods: We retrospectively reviewed our clinical experience at National Jewish Medical and Research Center for patients with surgical lung biopsy-proven fibrotic HP who had an acute decline in respiratory status and met criteria similar to those proposed for the diagnosis of an AE of IPF.Results: Over a 2-year period, we identified four patients with an AE of fibrotic HP. All patients had a clinical course similar to that most frequently described in AEs of IPF: respiratory failure requiring assisted ventilation, lack of clinical response to high-dose corticosteroid therapy, and a poor prognosis (all cases resulted in death or emergent lung transplantation). Lung biopsy at the time of the AE, explant, or autopsy revealed organizing diffuse alveolar damage superimposed on fibrotic lung disease.Conclusions: Fibrotic HP, like other forms of fibrotic lung disease, can be associated with AEs of disease. Further investigation into similarities and pathways common in AEs of various fibrotic lung diseases may yield additional insight into this recently recognized syndrome. [ABSTRACT FROM AUTHOR]

Purposes: To evaluate the pathologic patterns, clinical features, and survival among subjects with scleroderma (ie, systemic sclerosis [SSc]) and clinically significant interstitial lung disease (ILD) evaluated at an ILD center.Methods: Retrospective cohort study of all SSc patients who had been referred for further evaluation of ILD and had undergone surgical lung biopsy. Clinical data were abstracted by review of the medical record, and lung biopsy specimens were reviewed and classified according to current pathologic criteria.Results: All patients presented with significant respiratory symptoms. Twenty-two of 27 subjects had surgical lung biopsy-proven ILD, and 5 subjects had miscellaneous non-ILD patterns. Of those subjects with ILD, 64% (14 of 22 subjects) had a nonspecific interstitial pneumonia (NSIP) pathologic pattern (fibrotic NSIP, 13 subjects; cellular NSIP, 1 subject), and 36% (8 of 22 subjects) had the usual interstitial pneumonia (UIP) pattern. Subjects with NSIP were younger (median age, 42 vs 58 years, respectively; p = 0.003), but no differences were noted in pulmonary physiology (FVC: NSIP group, 52% predicted; UIP group, 65% predicted; p = 0.22; diffusing capacity of the lung for carbon monoxide: NSIP group, 40% predicted; UIP group, 42% predicted; p = 1.0). All patients had limited skin involvement. The Scl-70 antibody was absent among those assessed (NSIP group, 0 of 10 subjects; UIP group, 0 of 7 subjects). All patients were treated with cytotoxic therapy. The median survival time for those with NSIP was 15.3 years (5,596 days) compared with 3 years (1,084 days) for those with UIP (p = 0.07 [log-rank test]).Conclusions: In SSc patients with limited cutaneous disease and clinically significant ILD, fibrotic NSIP and UIP are the predominant pathologic patterns. Those with the UIP pattern of disease had a trend toward shorter survival time. [ABSTRACT FROM AUTHOR]

Background: Fibrotic hypersensitivity pneumonitis (FHP) is an irreversible lung disease with high morbidity and mortality. We sought to evaluate the safety and effect of pirfenidone on disease progression in such patients., Methods: We conducted a single-centre, randomised, double-blinded, placebo-controlled trial in adults with FHP and disease progression. Patients were assigned in a 2:1 ratio to receive either oral pirfenidone (2403 mg/day) or placebo for 52 weeks. The primary end point was the mean absolute change in the per cent predicted forced vital capacity (FVC%). Secondary end points included progression-free survival (PFS, time to a relative decline ≥10% in FVC and/or diffusing capacity of the lung for carbon monoxide (DLCO), acute respiratory exacerbation, a decrease of ≥50 m in the 6 min walk distance, increase or introduction of immunosuppressive drugs or death), change in FVC slope and mean DLCO%, hospitalisations, radiological progression of lung fibrosis and safety., Results: After randomising 40 patients, enrolment was interrupted by the COVID-19 pandemic. There was no significant between-group difference in FVC% at week 52 (mean difference -0.76%, 95% CI -6.34 to 4.82). Pirfenidone resulted in a lower rate of decline in the adjusted FVC% at week 26 and improved PFS (HR 0.26, 95% CI 0.12 to 0.60). Results for other secondary end points showed no significant difference between groups. No deaths occurred in the pirfenidone group and one death (respiratory) occurred in the placebo group. There were no treatment-emergent serious adverse events., Conclusions: The trial was underpowered to detect a difference in the primary end point. Pirfenidone was found to be safe and improved PFS in patients with FHP., Trial Registration Mumber: NCT02958917., Competing Interests: Competing interests: ERFP reports a relationship with Genentech, Boehringer Ingelheim and with National Heart Lung and Blood Institute that includes funding grants. All other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Cysts and cavities in the lung are commonly encountered on chest imaging. It is necessary to distinguish thin-walled lung cysts (≤2 mm) from cavities and characterize their distribution as focal or multifocal versus diffuse. Focal cavitary lesions are often caused by inflammatory, infectious, or neoplastic processes in contrast to diffuse cystic lung diseases. An algorithmic approach to diffuse cystic lung disease can help narrow the differential diagnosis, and additional testing such as skin biopsy, serum biomarkers, and genetic testing can be confirmatory. An accurate diagnosis is essential for the management and disease surveillance of extrapulmonary complications., (Copyright © 2023 Elsevier Inc. All rights reserved.)

A subset of individuals who recover from coronavirus disease 2019 (COVID-19) develop post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PASC), but the mechanistic basis of PASC-associated lung abnormalities suffers from a lack of longitudinal tissue samples. The mouse-adapted SARS-CoV-2 strain MA10 produces an acute respiratory distress syndrome in mice similar to humans. To investigate PASC pathogenesis, studies of MA10-infected mice were extended from acute to clinical recovery phases. At 15 to 120 days after virus clearance, pulmonary histologic findings included subpleural lesions composed of collagen, proliferative fibroblasts, and chronic inflammation, including tertiary lymphoid structures. Longitudinal spatial transcriptional profiling identified global reparative and fibrotic pathways dysregulated in diseased regions, similar to human COVID-19. Populations of alveolar intermediate cells, coupled with focal up-regulation of profibrotic markers, were identified in persistently diseased regions. Early intervention with antiviral EIDD-2801 reduced chronic disease, and early antifibrotic agent (nintedanib) intervention modified early disease severity. This murine model provides opportunities to identify pathways associated with persistent SARS-CoV-2 pulmonary disease and test countermeasures to ameliorate PASC.

COVID-19 survivors develop post-acute sequelae of SARS-CoV-2 (PASC), but the mechanistic basis of PASC-associated lung abnormalities suffers from a lack of longitudinal samples. Mouse-adapted SARS-CoV-2 MA10 produces an acute respiratory distress syndrome (ARDS) in mice similar to humans. To investigate PASC pathogenesis, studies of MA10-infected mice were extended from acute disease through clinical recovery. At 15-120 days post-virus clearance, histologic evaluation identified subpleural lesions containing collagen, proliferative fibroblasts, and chronic inflammation with tertiary lymphoid structures. Longitudinal spatial transcriptional profiling identified global reparative and fibrotic pathways dysregulated in diseased regions, similar to human COVID-19. Populations of alveolar intermediate cells, coupled with focal upregulation of pro-fibrotic markers, were identified in persistently diseased regions. Early intervention with antiviral EIDD-2801 reduced chronic disease, and early anti-fibrotic agent (nintedanib) intervention modified early disease severity. This murine model provides opportunities to identify pathways associated with persistent SARS-CoV-2 pulmonary disease and test countermeasures to ameliorate PASC.

Advancements in methods, technology, and our understanding of the pathobiology of lung injury have created the need to update the definition of experimental acute lung injury (ALI). We queried 50 participants with expertise in ALI and acute respiratory distress syndrome using a Delphi method composed of a series of electronic surveys and a virtual workshop. We propose that ALI presents as a "multidimensional entity" characterized by four "domains" that reflect the key pathophysiologic features and underlying biology of human acute respiratory distress syndrome. These domains are 1 ) histological evidence of tissue injury, 2 ) alteration of the alveolar-capillary barrier, 3 ) presence of an inflammatory response, and 4 ) physiologic dysfunction. For each domain, we present "relevant measurements," defined as those proposed by at least 30% of respondents. We propose that experimental ALI encompasses a continuum of models ranging from those focusing on gaining specific mechanistic insights to those primarily concerned with preclinical testing of novel therapeutics or interventions. We suggest that mechanistic studies may justifiably focus on a single domain of lung injury, but models must document alterations of at least three of the four domains to qualify as "experimental ALI." Finally, we propose that a time criterion defining "acute" in ALI remains relevant, but the actual time may vary based on the specific model and the aspect of injury being modeled. The continuum concept of ALI increases the flexibility and applicability of the definition to multiple models while increasing the likelihood of translating preclinical findings to critically ill patients.

Hypersensitivity pneumonitis (HP) is an immunologically mediated form of lung disease resulting from inhalational exposure to any of a large variety of antigens. A subgroup of patients with HP develops pulmonary fibrosis (fibrotic HP; FHP), a significant cause of morbidity and mortality. This study will evaluate the safety and efficacy of the antifibrotic pirfenidone in treating FHP. This single-centre, randomised, double-blind, placebo-controlled trial is enrolling adults with FHP (ClinicalTrials.gov: NCT02958917). Study participants must have fibrotic abnormalities involving ≥5% of the lung parenchyma on high-resolution computed tomography scan, forced vital capacity (FVC) ≥40% and diffusing capacity of the lung for carbon monoxide ≥30% of predicted values. Study participants will be randomised in a 2:1 ratio to receive pirfenidone 2403 mg·day -1 or placebo. The primary efficacy end-point is the mean change in FVC % predicted from baseline to week 52. A number of secondary end-points have been chosen to evaluate the safety and efficacy in different domains., Competing Interests: Conflict of interest: E.R. Fernández Pérez reports grants from the NHLBI and Boehringer Ingelheim outside the submitted work. Conflict of interest: J.L. Crooks has nothing to disclose. Conflict of interest: J.J. Swigris has nothing to disclose. Conflict of interest: J.J. Solomon has nothing to disclose. Conflict of interest: M.P. Mohning has nothing to disclose. Conflict of interest: T.J. Huie has nothing to disclose. Conflict of interest: M. Koslow has nothing to disclose. Conflict of interest: D.A. Lynch has nothing to disclose. Conflict of interest: S.D. Groshong has nothing to disclose. Conflict of interest: K.F. Fier has nothing to disclose., (Copyright ©The authors 2021.)

Rationale: Usual interstitial pneumonia (UIP) is the defining morphology of idiopathic pulmonary fibrosis (IPF). Guidelines for IPF diagnosis conditionally recommend surgical lung biopsy for histopathology diagnosis of UIP when radiology and clinical context are not definitive. A "molecular diagnosis of UIP" in transbronchial lung biopsy, the Envisia Genomic Classifier, accurately predicted histopathologic UIP. Objectives: We evaluated the combined accuracy of the Envisia Genomic Classifier and local radiology in the detection of UIP pattern. Methods: Ninety-six patients who had diagnostic lung pathology as well as a transbronchial lung biopsy for molecular testing with Envisia Genomic Classifier were included in this analysis. The classifier results were scored against reference pathology. UIP identified on high-resolution computed tomography (HRCT) as documented by features in local radiologists' reports was compared with histopathology. Measurements and Main Results: In 96 patients, the Envisia Classifier achieved a specificity of 92.1% (confidence interval [CI],78.6-98.3%) and a sensitivity of 60.3% (CI, 46.6-73.0%) for histology-proven UIP pattern. Local radiologists identified UIP in 18 of 53 patients with UIP histopathology, with a sensitivity of 34.0% (CI, 21.5-48.3%) and a specificity of 96.9% (CI, 83.8-100%). In conjunction with HRCT patterns of UIP, the Envisia Classifier results identified 24 additional patients with UIP (sensitivity 79.2%; specificity 90.6%). Conclusions: In 96 patients with suspected interstitial lung disease, the Envisia Genomic Classifier identified UIP regardless of HRCT pattern. These results suggest that recognition of a UIP pattern by the Envisia Genomic Classifier combined with HRCT and clinical factors in a multidisciplinary discussion may assist clinicians in making an interstitial lung disease (especially IPF) diagnosis without the need for a surgical lung biopsy.

Idiopathic pulmonary fibrosis (IPF) is a progressive, often fatal, fibrosing lung disease for which treatment remains suboptimal. Fibrogenic cytokines, including transforming growth factor-β (TGF-β), are central to its pathogenesis. Protein tyrosine phosphatase-α (PTPα) has emerged as a key regulator of fibrogenic signaling in fibroblasts. We have reported that mice globally deficient in PTPα ( Ptpra -/- ) were protected from experimental pulmonary fibrosis, in part via alterations in TGF-β signaling. The goal of this study was to determine the lung cell types and mechanisms by which PTPα controls fibrogenic pathways and whether these pathways are relevant to human disease. Immunohistochemical analysis of lungs from patients with IPF revealed that PTPα was highly expressed by mesenchymal cells in fibroblastic foci and by airway and alveolar epithelial cells. To determine whether PTPα promotes profibrotic signaling pathways in lung fibroblasts and/or epithelial cells, we generated mice with conditional (floxed) Ptpra alleles ( Ptpra f/f ). These mice were crossed with Dermo1 -Cre or with Sftpc -CreER T2 mice to delete Ptpra in mesenchymal cells and alveolar type II cells, respectively. Dermo1 -Cre/ Ptpra f/f mice were protected from bleomycin-induced pulmonary fibrosis, whereas Sftpc- CreER T2 /Ptpra f/f mice developed pulmonary fibrosis equivalent to controls. Both canonical and noncanonical TGF-β signaling and downstream TGF-β-induced fibrogenic responses were attenuated in isolated Ptpra -/- compared with wild-type fibroblasts. Furthermore, TGF-β-induced tyrosine phosphorylation of TGF-β type II receptor and of PTPα were attenuated in Ptpra -/- compared with wild-type fibroblasts. The phenotype of cells genetically deficient in PTPα was recapitulated with the use of a Src inhibitor. These findings suggest that PTPα amplifies profibrotic TGF-β-dependent pathway signaling in lung fibroblasts.

This review provides an updated approach to the diagnosis and management of hypersensitivity pneumonitis (HP). The importance of using a multidisciplinary discussion to increase diagnostic and treatment confidence is emphasized. The role of Bayesian reasoning is highlighted throughout, underscoring the importance of hypothesis generation (differential diagnosis) and diagnostic test interpretation based on the probability of HP. Probability estimates of diagnostic certainty (i.e., a confident versus a working diagnosis) and treatment thresholds are carefully examined.Therapeutically, beyond antigen avoidance and newly available antifibrotic therapy for patients with a progressive fibrosing phenotype; the role, timing, and expected response to anti-inflammatory therapy in individual patients are unanswered questions. Since the evidence and validation of testing generally performed during the diagnostic work-up and longitudinal monitoring of HP is feeble at best, the viewpoints discussed are not intended to resolve current controversies but rather to provide a conceptual framework for evaluating discordant information when evaluating and caring for patients with HP., Competing Interests: Dr. Fernández Pérez reports grants from NHLBI, grants and personal fees from Boehringer Ingelheim, grants and personal fees from Genentech, outside the submitted work.Dr. Brown reports the following outside the submitted work: grants from NIH, and advisory board participation for the following Biogen, Blade, Boehringer Ingelheim, Galapagos, Galecto, Genoa, Lifemax, MedImmune, monARC Bionetworks, OSIC (Open Source Imaging Consortium), Pliant, ProMetic, Third Pole, Theravance, Three Lakes Partners, Veracyte., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Background: In the appropriate clinical setting, the diagnosis of idiopathic pulmonary fibrosis (IPF) requires a pattern of usual interstitial pneumonia to be present on high-resolution chest CT (HRCT) or surgical lung biopsy. A molecular usual interstitial pneumonia signature can be identified by a machine learning algorithm in less-invasive transbronchial lung biopsy samples. We report prospective findings for the clinical validity and utility of this molecular test., Methods: We prospectively recruited 237 patients for this study from those enrolled in the Bronchial Sample Collection for a Novel Genomic Test (BRAVE) study in 29 US and European sites. Patients were undergoing evaluation for interstitial lung disease and had had samples obtained by clinically indicated surgical or transbronchial biopsy or cryobiopsy for pathology. Histopathological diagnoses were made by experienced pathologists. Available HRCT scans were reviewed centrally. Three to five transbronchial lung biopsy samples were collected from all patients specifically for this study, pooled by patient, and extracted for transcriptomic sequencing. After exclusions, diagnostic histopathology and RNA sequence data from 90 patients were used to train a machine learning algorithm (Envisia Genomic Classifier, Veracyte, San Francisco, CA, USA) to identify a usual interstitial pneumonia pattern. The primary study endpoint was validation of the classifier in 49 patients by comparison with diagnostic histopathology. To assess clinical utility, we compared the agreement and confidence level of diagnosis made by central multidisciplinary teams based on anonymised clinical information and radiology results plus either molecular classifier or histopathology results., Findings: The classifier identified usual interstitial pneumonia in transbronchial lung biopsy samples from 49 patients with 88% specificity (95% CI 70-98) and 70% sensitivity (47-87). Among 42 of these patients who had possible or inconsistent usual interstitial pneumonia on HRCT, the classifier showed 81% positive predictive value (95% CI 54-96) for underlying biopsy-proven usual interstitial pneumonia. In the clinical utility analysis, we found 86% agreement (95% CI 78-92) between clinical diagnoses using classifier results and those using histopathology data. Diagnostic confidence was improved by the molecular classifier results compared with histopathology results in 18 with IPF diagnoses (proportion of diagnoses that were confident or provisional with high confidence 89% vs 56%, p=0·0339) and in all 48 patients with non-diagnostic pathology or non-classifiable fibrosis histopathology (63% vs 42%, p=0·0412)., Interpretation: The molecular test provided an objective method to aid clinicians and multidisciplinary teams in ascertaining a diagnosis of IPF, particularly for patients without a clear radiological diagnosis, in samples that can be obtained by a less invasive method. Further prospective clinical validation and utility studies are planned., Funding: Veracyte., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Common variable immunodeficiency (CVID) is associated with significant chronic lung disease. The purpose of this paper was to describe the clinical, radiologic, and pathologic findings of CVID-associated lung diseases. These include airways' disease, interstitial lung disease, lymphoma, and mucosa-associated lymphoid tissue lymphoma. In addition, a genetic syndrome termed Kabuki syndrome results in CVID-like immune abnormalities. These patients may also present with CVID-associated lung disease. Awareness and precise identification of CVID-associated lung disease may allow for better assessment of prognosis and direction of therapy.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a progressive, fibrotic interstitial lung disease characterized by (myo)fibroblast accumulation and collagen deposition. Resistance to Fas-induced apoptosis is thought to facilitate (myo)fibroblast persistence in fibrotic lung tissues by poorly understood mechanisms., Objectives: To test the hypothesis that PTPN13 (protein tyrosine phosphatase-N13) is expressed by IPF lung (myo)fibroblasts, promotes their resistance to Fas-induced apoptosis, and contributes to the development of pulmonary fibrosis., Methods: PTPN13 was localized in lung tissues from patients with IPF and control subjects by immunohistochemical staining. Inhibition of PTPN13 function in primary IPF and normal lung (myo)fibroblasts was accomplished by: 1) downregulation with TNF-α (tumor necrosis factor-α)/IFN-γ, 2) siRNA knockdown, or 3) a cell-permeable Fas/PTPN13 interaction inhibitory peptide. The role of PTPN13 in the development of pulmonary fibrosis was assessed in mice with genetic deficiency of PTP-BL, the murine ortholog of PTPN13., Measurements and Main Results: PTPN13 was constitutively expressed by (myo)fibroblasts in the fibroblastic foci of patients with IPF. Human lung (myo)fibroblasts, which are resistant to Fas-induced apoptosis, basally expressed PTPN13 in vitro. TNF-α/IFN-γ or siRNA-mediated PTPN13 downregulation and peptide-mediated inhibition of the Fas/PTPN13 interaction in human lung (myo)fibroblasts promoted Fas-induced apoptosis. Bleomycin-challenged PTP-BL -/- mice, while developing inflammatory lung injury, exhibited reduced pulmonary fibrosis compared with wild-type mice., Conclusions: These findings suggest that PTPN13 mediates the resistance of human lung (myo)fibroblasts to Fas-induced apoptosis and promotes pulmonary fibrosis in mice. Our results suggest that strategies aimed at interfering with PTPN13 expression or function may represent a novel strategy to reduce fibrosis in IPF.

The common gain-of-function MUC5B promoter variant ( rs35705950 ) is the strongest risk factor for the development of idiopathic pulmonary fibrosis (IPF). While the role of complement in IPF is controversial, both MUC5B and the complement system play a role in lung host defense. The aim of this study was to evaluate the relationship between complement component 3 (C3) and MUC5B in patients with IPF and in bleomycin-induced lung injury in mice. To do this, we evaluated C3 gene expression in whole lung tissue from 300 subjects with IPF and 175 healthy controls. Expression of C3 was higher in IPF than healthy controls {1.40-fold increase [95% confidence interval (CI) 1.31-1.50]; P < 0.0001} and even greater among IPF subjects with the highest-risk IPF MUC5B promoter genotype [TT vs. GG = 1.59-fold (95% CI 1.15-2.20); P < 0.05; TT vs. GT = 1.66-fold (95% CI 1.20-2.30); P < 0.05]. Among subjects with IPF, C3 expression was significantly higher in the lung tissue without microscopic honeycombing than in the lung tissue with microscopic honeycombing [1.40-fold increase (95% CI 1.23- 1.59); P < 0.01]. In mice, while bleomycin exposure increased Muc5b protein expression, C3-deficient mice were protected from bleomycin-induced lung injury. In aggregate, our findings indicate that the MUC5B promoter variant is associated with higher C3 expression and suggest that the complement system may contribute to the pathogenesis of IPF.

Rationale: Usual interstitial pneumonia (UIP) is the histopathologic hallmark of idiopathic pulmonary fibrosis. Although UIP can be detected by high-resolution computed tomography of the chest, the results are frequently inconclusive, and pathology from transbronchial biopsy (TBB) has poor sensitivity. Surgical lung biopsy may be necessary for a definitive diagnosis., Objectives: To develop a genomic classifier in tissue obtained by TBB that distinguishes UIP from non-UIP, trained against central pathology as the reference standard., Methods: Exome enriched RNA sequencing was performed on 283 TBBs from 84 subjects. Machine learning was used to train an algorithm with high rule-in (specificity) performance using specimens from 53 subjects. Performance was evaluated by cross-validation and on an independent test set of specimens from 31 subjects. We explored the feasibility of a single molecular test per subject by combining multiple TBBs from upper and lower lobes. To address whether classifier accuracy depends upon adequate alveolar sampling, we tested for correlation between classifier accuracy and expression of alveolar-specific genes., Results: The top-performing algorithm distinguishes UIP from non-UIP conditions in single TBB samples with an area under the receiver operator characteristic curve (AUC) of 0.86, with specificity of 86% (confidence interval = 71-95%) and sensitivity of 63% (confidence interval = 51-74%) (31 test subjects). Performance improves to an AUC of 0.92 when three to five TBB samples per subject are combined at the RNA level for testing. Although we observed a wide range of type I and II alveolar-specific gene expression in TBBs, expression of these transcripts did not correlate with classifier accuracy., Conclusions: We demonstrate proof of principle that genomic analysis and machine learning improves the utility of TBB for the diagnosis of UIP, with greater sensitivity and specificity than pathology in TBB alone. Combining multiple individual subject samples results in increased test accuracy over single sample testing. This approach requires validation in an independent cohort of subjects before application in the clinic.

Rationale: Asymptomatic relatives of patients with familial interstitial pneumonia (FIP), the inherited form of idiopathic interstitial pneumonia, carry increased risk for developing interstitial lung disease., Objectives: Studying these at-risk individuals provides a unique opportunity to investigate early stages of FIP pathogenesis and develop predictive models of disease onset., Methods: Seventy-five asymptomatic first-degree relatives of FIP patients (mean age, 50.8 yr) underwent blood sampling and high-resolution chest computed tomography (HRCT) scanning in an ongoing cohort study; 72 consented to bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsies. Twenty-seven healthy individuals were used as control subjects., Measurements and Main Results: Eleven of 75 at-risk subjects (14%) had evidence of interstitial changes by HRCT, whereas 35.2% had abnormalities on transbronchial biopsies. No differences were noted in inflammatory cells in BAL between at-risk individuals and control subjects. At-risk subjects had increased herpesvirus DNA in cell-free BAL and evidence of herpesvirus antigen expression in alveolar epithelial cells (AECs), which correlated with expression of endoplasmic reticulum stress markers in AECs. Peripheral blood mononuclear cell and AEC telomere length were shorter in at-risk individuals than healthy control subjects. The minor allele frequency of the Muc5B rs35705950 promoter polymorphism was increased in at-risk subjects. Levels of several plasma biomarkers differed between at-risk subjects and control subjects, and correlated with abnormal HRCT scans., Conclusions: Evidence of lung parenchymal remodeling and epithelial dysfunction was identified in asymptomatic individuals at risk for FIP. Together, these findings offer new insights into the early pathogenesis of idiopathic interstitial pneumonia and provide an ongoing opportunity to characterize presymptomatic abnormalities that predict progression to clinical disease.

Background: The current usual interstitial pneumonitis (UIP)/idiopathic pulmonary fibrosis CT scan classification system excludes probable UIP as a diagnostic category. We sought to determine the predictive effect of probable UIP on CT scan on histology and the effect of the promoter polymorphism in MUC5B (rs35705950) on histologic and CT scan UIP diagnosis., Methods: The cohort included 201 subjects with pulmonary fibrosis who had lung tissue samples obtained within 1 year of chest CT scan. UIP diagnosis on CT scan was categorized as inconsistent with, indeterminate, probable, or definite UIP by two to three pulmonary radiologists. Tissue slides were scored by two expert pulmonary pathologists. All subjects with available DNA (N = 200) were genotyped for rs35705950., Results: The proportion of CT scan diagnoses were as follows: inconsistent with (69 of 201, 34.3%), indeterminate (72 of 201, 35.8%), probable (34 of 201, 16.9%), and definite (26 of 201, 12.9%) UIP. Subjects with probable UIP on CT scan were more likely to have histologic probable/definite UIP than subjects with indeterminate UIP on CT scan (82.4% [28 of 34] vs 54.2% [39 of 72]; P = .01). CT scan and microscopic honeycombing were not associated with each other (P = .76). The minor (T) allele of the MUC5B polymorphism was associated with concordant CT scan and histologic UIP diagnosis (P = .03)., Conclusions: Probable UIP on CT scan is associated with a higher rate of histologic UIP than indeterminate UIP on CT scan suggesting that they are distinct groups and should not be combined into a single CT scan category as currently recommended by guidelines. CT scan and microscopic honeycombing may be dissimilar entities. The T allele at rs35705950 predicts a UIP diagnosis by both chest CT scan and histology.

Platelet Endothelial Cell Adhesion Molecule 1 (PECAM-1) deficient mice in the FVB/n strain exhibit fatal chronic pulmonary fibrotic disease. The illness occurs in the absence of a detectable pro-inflammatory event. PECAM-1 is vital to the stability of vascular permeability, leukocyte extravasation, clotting of platelets, and clearance of apoptotic cells. We show here that the spontaneous development of fibrotic disease in PECAM-1 deficient FVB/n mice is characterized by early loss of vascular integrity in pulmonary capillaries, resulting in spontaneous microbleeds. Hemosiderin-positive macrophages were found in interstitial spaces and bronchoalveolar lavage (BAL) fluid in relatively healthy animals. We also observed a gradually increasing presence of hemosiderin-positive macrophages and fibrin deposition in the advanced stages of disease, corresponding to the accumulation of collagen, IL-10 expression, and myofibroblasts expressing alpha smooth muscle actin (SMA). Together with the growing evidence that pulmonary microbleeds and coagulation play an active part in human pulmonary fibrosis, this data further supports our hypothesis that PECAM-1 expression is necessary for vascular barrier function control and regulation of homeostasis specifically, in the pulmonary environment., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Context: Gastrin-releasing peptide receptors (GRPRs) activate mitogen-activated protein kinase signaling pathway primarily through epidermal growth factor receptor activation and are under investigation as a molecular target because they are overexpressed in several solid tumors., Objective: To determine GRPR expression in both non-small cell lung carcinoma and small cell lung carcinoma, comparing results with clinical stages and demographic data., Design: We analyzed the immunohistochemical expression of GRPR in 200 non-small cell lung carcinoma and 38 small cell lung carcinoma archival cases from 2004 to 2008., Results: Non-small cell lung carcinoma cases tended to be higher GRPR expressers at a rate of 62.5% (weak, moderate, and strong expression in 41.5%, 13.5%, and 7.5%, respectively), compared with 52.62% in small cell lung carcinoma cases (weak, moderate, and strong expression in 34.21%, 15.78%, and 2.63%, respectively; P = .30). In non-small cell lung carcinoma there was a trend for higher percentages of strong expression in adenocarcinoma cases (10%; P = .67), and in patients with advanced stages (III and IV; 9.43% and 6.9%; P = .01)., Conclusions: To the best of our knowledge, this is the first study to demonstrate GRPR tissue expression in a large population of patients with lung cancer. Although GRPR expression was similar in small cell and non-small cell carcinoma, the expression was more pronounced in an advanced-stage lung cancer, particularly in adenocarcinoma cases, and may represent a potential target for the development of new treatment approaches in this population.

Background: Idiopathic pulmonary fibrosis (IPF) is an untreatable lung disease with a median survival of only 3-5 years that is diagnosed using a combination of clinical, radiographic and pathologic criteria. Histologically, IPF is characterised by usual interstitial pneumonia (UIP), a fibrosing interstitial pneumonia with a pattern of heterogeneous, subpleural regions of fibrotic and remodelled lung. We hypothesised that gene expression profiles of lung tissue may identify molecular subtypes of disease that could classify subtypes of IPF/UIP that have clinical implications., Methods and Findings: We collected transcriptional profiles on lung tissue from 119 patients with IPF/UIP and 50 non-diseased controls. Differential expression of individual transcripts was identified using an analysis of covariance (ANCOVA) model incorporating the clinical diagnosis of each patient as well as age, gender and smoking status. Validation was performed in an independent cohort of 111 IPF/UIP and 39 non-diseased controls. Our analysis identified two subtypes of IPF/UIP based on a strong molecular signature associated with expression of genes previously associated with fibrosis (matrix metalloproteinases, osteopontin, keratins), cilium genes and genes with unknown function. We demonstrate that elevated expression of cilium genes is associated with more extensive microscopic honeycombing and higher expression of both the airway mucin gene MUC5B and the metalloproteinase MMP7, a gene recently implicated in attenuating ciliated cell differentiation during wound repair., Conclusions: Expression of cilium genes appears to identify two unique molecular phenotypes of IPF/UIP. The different molecular profiles may be relevant to therapeutic responsiveness in patients with IPF/UIP.

Human tracheobronchial epithelial (TBE) basal cells (BCs) function as progenitors in normal tissue. However, mechanistic studies are typically performed in vitro and frequently use BCs recovered from patients who die of nonrespiratory disease. It is not known whether the cadaveric epithelium (1) is undergoing homeostatic remodeling and/or repair, or (2) yields BC clones that represent homeostatic processes identified in tissue. We sought to compare the phenotype of TBE-BCs with that of BCs cultured under optimal clone-forming conditions. TBE pathology was evaluated using quantitative histomorphometry. The cultured BC phenotype was determined by fluorescence-activated cell sorter analysis. Clone organization and cell phenotype were determined by immunostaining. The cadaveric TBE is 20% normal. In these regions, BCs are keratin (K)-5(+) and tetraspanin CD151(+), and demonstrate a low mitotic index. In contrast, 80% of the cadaveric TBE exhibits homeostatic remodeling/repair processes. In these regions, BCs are K5(+)/K14(+), and a subset expresses tissue factor (TF). Passage 1 TBE cells are BCs that are K5(+)/TF(+), and half coexpress CD151. Optimal clone formation conditions use an irradiated NIH3T3 fibroblast feeder layer (American Type Culture Collection, Frederick, MD) and serum-supplemented Epicult-B medium (Stemcell Technologies, La Jolla, CA). The TF(+)/CD151(-) BC subpopulation is the most clonogenic BC subtype, and is enriched with K14(+) cells. TF(+)/CD151(-) BCs generate clones containing BCs that are K5(+)/Trp63(+), but K14(-)/CD151(-). TF(+) cells are limited to the clone edge. In conclusion, clonogenic human TBE BCs (1) exhibit a molecular phenotype that is a composite of the normal and remodeling/reparative BC phenotypes observed in tissue, and (2) generate organoid clones that contain phenotypically distinct BC subpopulations.

Background: We previously identified a MUC5B gene promoter-variant that is a risk allele for sporadic and familial Idiopathic Pulmonary Fibrosis/Usual Interstitial Pneumonia (IPF/UIP). This allele was strongly associated with increased MUC5B gene expression in lung tissue from unaffected subjects. Despite the strong association of this airway epithelial marker with disease, little is known of mucin expressing structures or of airway involvement in IPF/UIP., Methods: Immunofluorescence was used to subtype mucus cells according to MUC5B and MUC5AC expression and to identify ciliated, basal, and alveolar type II (ATII) cells in tissue sections from control and IPF/UIP subjects. Staining patterns were quantified for distal airways (Control and IPF/UIP) and in honeycomb cysts (HC)., Results: MUC5B-expressing cells (EC) were detected in the majority of control distal airways. MUC5AC-EC were identified in half of these airways and only in airways that contained MUC5B-EC. The frequency of MUC5B+ and MUC5AC+ distal airways was increased in IPF/UIP subjects. MUC5B-EC were the dominant mucus cell type in the HC epithelium. The distal airway epithelium from control and IPF/UIP subjects and HC was populated by basal and ciliated cells. Most honeycombing regions were distinct from ATII hyperplasic regions. ATII cells were undetectable in the overwhelming majority of HC., Conclusions: The distal airway contains a pseudostratified mucocilary epithelium that is defined by basal epithelial cells and mucus cells that express MUC5B predominantly. These data suggest that the HC is derived from the distal airway.

Background: Lymphangiogenesis responds to tissue injury as a key component of normal wound healing. The development of fibrosis in the idiopathic interstitial pneumonias may result from abnormal wound healing in response to injury. We hypothesize that increased lymphatic vessel (LV) length, a marker of lymphangiogenesis, is associated with parenchymal components of the fibroblast reticulum (organizing collagen, fibrotic collagen, and fibroblast foci), and its extent correlates with disease severity., Methods: We assessed stereologically the parenchymal structure of fibrotic lungs and its associated lymphatic network, which was highlighted immunohistochemically in age-matched samples of usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP) with FVC &lt; 80%, COPD with a Global Initiative for Obstructive Lung Disease stage 0, and normal control lungs., Results: LV length density, as opposed to vessel volume density, was found to be associated with organizing and fibrotic collagen density (P &lt; .0001). Length density of LVs and the volume density of organizing and fibrotic collagen were significantly associated with severity of both % FVC (P &lt; .001) and diffusing capacity of the lung for carbon monoxide (P &lt; .001)., Conclusions: Severity of disease in UIP and NSIP is associated with increased LV length and is strongly associated with components of the fibroblast reticulum, namely organizing and fibrotic collagen, which supports a pathogenic role of LVs in these two diseases. Furthermore, the absence of definable differences between UIP and NSIP suggests that LVs are a unifying mechanism for the development of fibrosis in these fibrotic lung diseases.

Rationale: The impact of modern treatments of pulmonary arterial hypertension (PAH) on pulmonary vascular pathology remains unknown., Objectives: To assess the spectrum of pulmonary vascular remodeling in the modern era of PAH medication., Methods: Assessment of pulmonary vascular remodeling and inflammation in 62 PAH and 28 control explanted lungs systematically sampled., Measurements and Main Results: Intima and intima plus media fractional thicknesses of pulmonary arteries were increased in the PAH group versus the control lungs and correlated with pulmonary hemodynamic measurements. Despite a high variability of morphological measurements within a given PAH lung and among all PAH lungs, distinct pathological subphenotypes were detected in cohorts of PAH lungs. These included a subset of lungs lacking intima or, most prominently, media remodeling, which had similar numbers of profiles of plexiform lesions as those in lungs with more pronounced remodeling. Marked perivascular inflammation was present in a high number of PAH lungs and correlated with intima plus media remodeling. The number of profiles of plexiform lesions was significantly lower in lungs of male patients and those never treated with prostacyclin or its analogs., Conclusions: Our results indicate that multiple features of pulmonary vascular remodeling are present in patients treated with modern PAH therapies. Perivascular inflammation may have an important role in the processes of vascular remodeling, all of which may ultimately lead to increased pulmonary artery pressure. Moreover, our study provides a framework to interpret and design translational studies in PAH.

Objective: We sought to characterize a novel cohort of patients with lung disease, anti-cyclic citrullinated peptide (CCP) antibody positivity, without rheumatoid arthritis (RA) or other connective tissue disease (CTD)., Methods: The study sample included 74 subjects with respiratory symptoms, evaluated January 2008-January 2010 and found to have a positive anti-CCP antibody but no evidence for RA or other CTD. Each underwent serologic testing, pulmonary physiology testing, and thoracic high-resolution computed tomography (HRCT) scan as part of routine clinical evaluation., Results: The majority of subjects were women, and most were former cigarette smokers. Four distinct radiographic phenotypes were identified: isolated airways disease (54%), isolated interstitial lung disease (ILD) (14%), mixed airways disease and ILD (26%), and combined pulmonary fibrosis with emphysema (7%). This cohort had a predominance of airways disease, either in isolation or along with a usual interstitial pneumonia-pattern of ILD. Among subjects with high-titer anti-CCP positivity (n=33), three developed the articular manifestations of RA during a median follow-up of 449 days., Conclusion: We have described a unique cohort of patients with anti-CCP antibody positivity and lung disease in the absence of existing RA or other CTD. The lung phenotypic characteristics of this cohort resemble those of established RA and a few of these patients have developed articular RA within a short period of follow-up. The implications of a positive anti-CCP antibody among patients with lung disease but not RA are not yet known, but we believe requires further investigation., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Idiopathic pulmonary fibrosis (IPF) is associated with the accumulation of collagen-secreting fibroblasts and myofibroblasts in the lung parenchyma. Many mechanisms contribute to their accumulation, including resistance to apoptosis. In previous work, we showed that exposure to the proinflammatory cytokines TNF-α and IFN-γ reverses the resistance of lung fibroblasts to apoptosis. In this study, we investigate the underlying mechanisms. Based on an interrogation of the transcriptomes of unstimulated and TNF-α- and IFN-γ-stimulated primary lung fibroblasts and the lung fibroblast cell line MRC5, we show that among Fas-signaling pathway molecules, Fas expression was increased ∼6-fold in an NF-κB- and p38(mapk)-dependent fashion. Prevention of the increase in Fas expression using Fas small interfering RNAs blocked the ability of TNF-α and IFN-γ to sensitize fibroblasts to Fas ligation-induced apoptosis, whereas enforced adenovirus-mediated Fas overexpression was sufficient to overcome basal resistance to Fas-induced apoptosis. Examination of lung tissues from IPF patients revealed low to absent staining of Fas in fibroblastic cells of fibroblast foci. Collectively, these findings suggest that increased expression of Fas is necessary and sufficient to overcome the resistance of lung fibroblasts to Fas-induced apoptosis. Our findings also suggest that approaches aimed at increasing Fas expression by lung fibroblasts and myofibroblasts may be therapeutically relevant in IPF.

Background: The mutations that have been implicated in pulmonary fibrosis account for only a small proportion of the population risk., Methods: Using a genomewide linkage scan, we detected linkage between idiopathic interstitial pneumonia and a 3.4-Mb region of chromosome 11p15 in 82 families. We then evaluated genetic variation in this region in gel-forming mucin genes expressed in the lung among 83 subjects with familial interstitial pneumonia, 492 subjects with idiopathic pulmonary fibrosis, and 322 controls. MUC5B expression was assessed in lung tissue., Results: Linkage and fine mapping were used to identify a region of interest on the p-terminus of chromosome 11 that included gel-forming mucin genes. The minor-allele of the single-nucleotide polymorphism (SNP) rs35705950, located 3 kb upstream of the MUC5B transcription start site, was present at a frequency of 34% among subjects with familial interstitial pneumonia, 38% among subjects with idiopathic pulmonary fibrosis, and 9% among controls (allelic association with familial interstitial pneumonia, P=1.2×10(-15); allelic association with idiopathic pulmonary fibrosis, P=2.5×10(-37)). The odds ratios for disease among subjects who were heterozygous and those who were homozygous for the minor allele of this SNP were 6.8 (95% confidence interval [CI], 3.9 to 12.0) and 20.8 (95% CI, 3.8 to 113.7), respectively, for familial interstitial pneumonia and 9.0 (95% CI, 6.2 to 13.1) and 21.8 (95% CI, 5.1 to 93.5), respectively, for idiopathic pulmonary fibrosis. MUC5B expression in the lung was 14.1 times as high in subjects who had idiopathic pulmonary fibrosis as in those who did not (P<0.001). The variant allele of rs35705950 was associated with up-regulation in MUC5B expression in the lung in unaffected subjects (expression was 37.4 times as high as in unaffected subjects homozygous for the wild-type allele, P<0.001). MUC5B protein was expressed in lesions of idiopathic pulmonary fibrosis., Conclusions: A common polymorphism in the promoter of MUC5B is associated with familial interstitial pneumonia and idiopathic pulmonary fibrosis. Our findings suggest that dysregulated MUC5B expression in the lung may be involved in the pathogenesis of pulmonary fibrosis. (Funded by the National Heart, Lung, and Blood Institute and others.).

Background and Objective: A comprehensive diagnostic evaluation is recommended for all patients with fibrotic lung disease and acute respiratory decompensation. However, the effect on clinical outcomes of this evaluation remains unknown., Methods: We evaluated 27 consecutive patients with fibrotic lung disease who were hospitalized for an acute respiratory decline between June 2006 and April 2009. An interstitial lung disease expert assisted with the acute care of each patient. A retrospective review of the patient charts was performed to obtain demographic and clinical data, and to assess outcomes., Results: Using a strict definition of acute exacerbation (AE) of fibrotic lung disease derived from the IPF Network Pulmonary Perspective statement, 10 of the 27 patients were classified as definite AE and nine as suspected AE. In eight patients, infectious agents were identified as potential explanations for the respiratory decline. No patients with congestive heart failure or pulmonary embolism were identified. Overall survival to discharge was 37.0%. One-year survival was 14.8%. There were no differences in outcomes for patients with AE compared with those for whom potential infectious aetiologies were identified (log rank, P = 0.932). Patients with IPF showed a decreased rate of survival compared with patients with non-IPF fibrotic disease (1-year survival 0% vs 28.6%, log rank, P = 0.045)., Conclusions: In patients with fibrotic lung disease and an acute respiratory decline, a detailed diagnostic evaluation revealed a potential infectious aetiology in up to one-third of cases. However, there was no association between this finding and outcomes in these patients. One-year survival was dismal in patients who suffered an acute respiratory decompensation.

Two primary prevention trials unexpectedly showed adverse effects of supplemental beta-carotene on lung cancer incidence in cigarette smokers. To elucidate the molecular mechanisms that might underlie these effects, we studied the immunohistochemical expression of cytochrome P450 1A1, 1A2, and 2E1, retinoic acid receptor beta, activated protein-1 elements, cyclin D1, and Ki67 in lung tumors and, when available, adjacent normal tissues obtained from incident cases in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Archival lung tissue was available from 52 men randomized to receive 20 mg of beta-carotene per day and 30 men randomized to the placebo arm, all of whom were diagnosed with incident non-small-cell lung carcinoma during the course of the trial and subsequently underwent radical pulmonary resection. In normal-appearing bronchial epithelium, positive staining for cyclin D1 was observed in 23% of cases in the beta-carotene group and 0% of cases in the placebo group (based on only 3 of 13 versus 0 of 11 cases staining positively, however; P = 0.04), with no differences in expression noted in lung tumor tissue (P = 0.48). There were no statistically significant differences in Ki67 expression in normal or cancerous lung tissue between intervention groups, although a small increase in staining in tumors was noted among cases in the beta-carotene versus placebo group (88% versus 71% of cases stained positive, respectively; P = 0.13). Contrary to expectation, beta-carotene supplementation had no apparent effect on retinoic acid receptor-beta expression. These findings suggest that male smokers supplemented with beta-carotene may have had an increased risk of lung cancer due to aberrant cell growth, although our results are based on a relatively small number of cases and require confirmation in other completed trials of beta-carotene supplementation., (2010 AACR.)

Increased apoptosis of alveolar epithelial cells and impaired apoptosis of myofibroblasts have been linked to the pathogenesis of idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP). Fas, a death receptor of the TNF-receptor superfamily, has been implicated in apoptosis of both cell types, though the mechanisms are poorly understood. The goals of this study were: (1) to examine the localization of Fas-associated death-domain-like IL-1beta-converting enzyme inhibitory protein (c-FLIP), an NF-kappaB-dependent regulator of Fas-signaling, in lung tissues from IPF/UIP patients and control subjects; and (2) to compare c-FLIP expression with epithelial cell and myofibroblast apoptosis, proliferation, and NF-kappaB activation. c-FLIP expression was restricted to airway epithelial cells in control lung tissues. In contrast, in patients with IPF/UIP, c-FLIP was also expressed by alveolar epithelial cells in areas of injury and fibrosis, but was absent from myofibroblasts in fibroblastic foci and from alveolar epithelial cells in uninvolved areas of lung tissue. Quantification of apoptosis and proliferation revealed an absence of apoptotic or proliferating cells in fibroblastic foci and low levels of apoptosis and proliferation by alveolar epithelial cells. Quantification of NF-kappaB expression and nuclear translocation revealed strong staining and translocation in alveolar epithelial cells and weak staining and minimal nuclear translocation in myofibroblasts. These findings suggest that: (1) c-FLIP expression is induced in the abnormal alveolar epithelium of patients with IPF/UIP, (2) the resistance of myofibroblasts to apoptosis in patients with IPF/UIP occurs independently of c-FLIP expression, and (3) increased NF-kappaB activation and c-FLIP expression by the alveolar epithelium may be linked.

The rat coronavirus sialodacryoadenitis virus (SDAV) causes respiratory infection and provides a system for investigating respiratory coronaviruses in a natural host. A viral suspension in the form of a microspray aerosol was delivered by intratracheal instillation into the distal lung of 6-8-week-old Fischer 344 rats. SDAV inoculation produced a 7 % body weight loss over a 5 day period that was followed by recovery over the next 7 days. SDAV caused focal lesions in the lung, which were most severe on day 4 post-inoculation (p.i.). Immunofluorescent staining showed that four cell types supported SDAV virus replication in the lower respiratory tract, namely Clara cells, ciliated cells in the bronchial airway and alveolar type I and type II cells in the lung parenchyma. In bronchial alveolar lavage fluid (BALF) a neutrophil influx increased the population of neutrophils to 45 % compared with 6 % of the cells in control samples on day 2 after mock inoculation. Virus infection induced an increase in surfactant protein SP-D levels in BALF of infected rats on days 4 and 8 p.i. that subsided by day 12. The concentrations of chemokines MCP-1, LIX and CINC-1 in BALF increased on day 4 p.i., but returned to control levels by day 8. Intratracheal instillation of rats with SDAV coronavirus caused an acute, self-limited infection that is a useful model for studying the early events of the innate immune response to respiratory coronavirus infections in lungs of the natural virus host.

Efficient removal of apoptotic cells is essential for resolution of inflammation. Failure to clear dying cells can exacerbate lung injury and lead to persistent inflammation and autoimmunity. Here we show that TNFalpha blocks apoptotic cell clearance by alveolar macrophages and leads to proinflammatory responses in the lung. Compared with mice treated with intratracheal TNFalpha or exogenous apoptotic cells, mice treated with the combination of TNFalpha plus apoptotic cells demonstrated reduced apoptotic cell clearance from the lungs and increased recruitment of inflammatory leukocytes to the air spaces. Treatment with intratracheal TNFalpha had no effect on the removal of exogenous apoptotic cells from the lungs of TNFalpha receptor-1 (p55) and -2 (p75) double mutant mice and no effect on leukocyte recruitment. Bronchoalveolar lavage from mice treated with TNFalpha plus apoptotic cells contained increased levels of proinflammatory cytokines IL-6, KC, and MCP-1, but exhibited no change in levels of anti-inflammatory cytokines IL-10 and TGF-beta. Administration of TNFalpha plus apoptotic cells during LPS-induced lung injury augmented neutrophil accumulation and proinflammatory cytokine production. These findings suggest that the presence of TNFalpha in the lung can alter the response of phagocytes to apoptotic cells leading to inflammatory cell recruitment and proinflammatory mediator production.

Gammaherpesviruses are tightly controlled by the host immune response, with gammaherpesvirus-associated malignancies prevalent in immune-suppressed individuals. Previously, infection of IFNgamma-unresponsive mice with gammaherpesvirus 68 (gammaHV68) showed that IFNgamma controlled chronic infection, limiting chronic diseases including arteritis and pulmonary fibrosis. Here, we show that gammaHV68-infected IFNgamma receptor-deficient (IFNgammaR(-/-)) mice uniformly develop angiocentric inflammatory lesions in the lung. Prolonged infection revealed a range of outcomes, from spontaneous regression to pulmonary lymphoma. By 12 months of infection, 80% of mice had lymphoid hyperplasia or pulmonary lymphoma; 45% of infected mice developed frank tumors between 5 and 12 months postinfection, with some mice showing systemic involvement. Lymphomas were composed of B lymphocytes and contained latently infected cells. Although IFNgammaR(-/-) mice control chronic gammaHV68 infection poorly, both early and late pathologies were indistinguishable between wild-type and reactivation-defective virus infection, indicating that, in contrast with other previously described gammaHV68-associated pathologies, these chronic diseases were not dependent on the reactivation of latent infection. This distinct combination of latent infection and defined host defect led to a specific and consistent lymphoproliferative disease. Significantly, this mouse model of virus-associated pulmonary B-cell lymphoma closely mimics the full spectrum of human lymphomatoid granulomatosis, an EBV-associated malignancy with no effective treatment.

Escherichia coli Ol57:H7 infection ranges from mild diarrheal illness to severe hemorrhagic colitis but may rarely be complicated by pseudomembranous colitis and/or necrosis. Herein, we report a sporadic case of ischemic E. coli Ol57:H7 pseudomembranous colitis in an adult that occurred during a national outbreak of E. coli Ol57:H7 in the United States.

Background: Usual interstitial pneumonia (UIP), the pathologic correlate of idiopathic pulmonary fibrosis, contains characteristic discrete areas of fibroblasts, myofibroblasts, and newly formed collagen, termed "fibroblast foci." These lesions are argued to represent isolated sites of recurrent acute lung injury and suggested to be the mechanism of disease progression. We hypothesized that, rather than isolated, these lesions are part of an organized neoplasm., Methods: Morphometric analysis of pentachrome-stained histologic sections of UIP was performed. Using point-counting technique on serial sections, fibroblast foci, arteries, and macrophage clusters were identified and we determined their individual "connectiveness" by estimating the Euler number. Two-dimensional micrographs were collated into a three-dimensional array from which a visual three-dimensional reconstruction could be constructed. Clonality analysis was performed using human androgen receptor gene methylation assay., Results: Blood vessels show significant connectivity with a Euler number of 2, whereas macrophage clusters exhibited no connectivity. The fibroblast foci showed a high level of interconnection with Euler numbers ranging from 19 to 39. The computer generated three-dimensional models provide a visual confirmation of this connectiveness. Human androgen receptor gene methylation assay analysis of the foci showed balanced methylation consistent with polyclonality., Conclusions: The fibroblast foci of UIP are the leading edge of a complex reticulum that is highly interconnected and extends from the pleura into the underlying parenchyma. It is a reactive, rather than a malignant, process.