Findings on High Resolution Computed Tomography in Symptomatic Veterans with Deployment-Related Lung Disease

PURPOSE

Military deployment to dusty, austere environments in Southwest Asia and Afghanistan is associated with symptomatic airways diseases including asthma and bronchiolitis. The utility of chest high-resolution computed tomographic (HRCT) imaging in lung disease diagnosis in this population is poorly understood. We investigated visual assessment of HRCT for identifying deployment-related lung disease compared with healthy controls.

MATERIALS AND METHODS

Chest HRCT images from 46 healthy controls and 45 symptomatic deployed military personnel with clinically confirmed asthma and/or biopsy-confirmed distal lung disease were scored by 3 independent thoracic radiologists. We compared demographic and clinical characteristics and frequency of imaging findings between deployers and controls, and between deployers with asthma and those with biopsy-confirmed distal lung disease, using χ2, Fisher exact or t tests, and logistic regression where appropriate. We also analyzed inter-rater agreement for imaging findings.

RESULTS

Expiratory air trapping was the only chest CT imaging finding that was significantly more frequent in deployers compared with controls. None of the 24 deployers with biopsy-confirmed bronchiolitis and/or granulomatous pneumonitis had HRCT findings of inspiratory mosaic attenuation or centrilobular nodularity. Only 2 of 21 with biopsy-proven emphysema had emphysema on HRCT.

CONCLUSIONS

Compared with surgical lung biopsy, visual assessment of HRCT showed few abnormalities in this small cohort of previously deployed symptomatic veterans with normal or near-normal spirometry.

Mining Tenure and Job Duties Differ Among Contemporary and Historic Underground Coal Miners With Progressive Massive Fibrosis

OBJECTIVE

To characterize differences in mining jobs and tenure between contemporary (born 1930+, working primarily with modern mining technologies) and historic coal miners with progressive massive fibrosis (PMF).

METHODS

We classified jobs as designated occupations (DOs) and non-DOs based on regulatory sampling requirements. Demographic, occupational characteristics, and histopathological PMF type were compared between groups.

RESULTS

Contemporary miners ( n = 33) had significantly shorter mean total (30.4 years vs 37.1 years, P = 0.0006) and underground (28.8 years vs 35.8 years, P = 0.001) mining tenure compared with historic miners ( n = 289). Silica-type PMF was significantly more common among miners in non-DOs (30.1% vs 15.8%, P = 0.03) and contemporary miners (58.1% vs 15.2%, P < 0.0001).

CONCLUSIONS

Primary jobs changed over time with the introduction of modern mining technologies and likely changed exposures for workers. Elevated crystalline silica exposures are likely in non-DOs and require attention.

The Spectrum of Pulmonary Histomorphology Changes in COVID-19 Cases

Introduction/Objective

Pulmonary specimens following COVID-19 virus infection demonstrate a spectrum of pulmonary histomorphology. Six patients with a history of COVID-19 infection are summarized in this review. The purpose of our study is to elucidate any possible correlations between clinical, laboratory, radiographic, and pathologic findings in COVID-19 patients. Further, we aim to characterize both non-specific and specific histomorphology and cytomorphology in COVID-19 patients.

Methods/Case Report

Six patients with known COVID-19 infection and lung biopsies/resections are identified. A chart review is performed to collect clinical histories, the results of COVID-19 PCR testing, radiographic impressions, pathologic interpretations of histology, and clinical outcomes. Information is summarized and tabulated.

Results (if a Case Study enter NA)

The most common, non-specific histological findings are focal/diffuse acute lung injury, organizing lung injury, or a combination of both patterns. Unique features of COVID-19 infection are identified in three cases, which illustrate viral cytopathic changes within hyperplastic pneumocytes. These include basophilic, vacuolated, granular cytoplasm and variably sized cytoplasmic/nuclear inclusions. Virus-loaded pneumocytes are typically identified in the organizing phase, and rarely in the acute lung injury phase. Immunohistochemical staining of anti-nuclear capsule antibody with appropriate controls shows focal positive staining in one case. SARS-CoV-2 PCR is positive in formalin-fixed paraffin-embedded (FFPE) tissue, while a serum PCR assay is negative.

Conclusion

The severity of clinical symptoms and clinical outcome are unrelated to the degree of lung involvement. Viral cytopathic changes are identified in three cases, with these specific findings associated with the organizing phase of lung injury, and either concurrent PCR positivity or positive immunohistochemical staining.

Single-cell transcriptome mapping identifies a local, innate B cell population driving chronic rejection after lung transplantation

Bronchiolitis obliterans syndrome (BOS) is the main reason for poor outcomes after lung transplantation (LTx). We and others have recently identified B cells as major contributors to BOS after LTx. The extent of B cell heterogeneity and the relative contributions of B cell subpopulations to BOS, however, remain unclear. Here, we provide a comprehensive analysis of cell population changes and their gene expression patterns during chronic rejection after orthotopic LTx in mice. Of 11 major cell types, Mzb1-expressing plasma cells (PCs) were the most prominently increased population in BOS lungs. These findings were validated in 2 different cohorts of human BOS after LTx. A Bhlhe41, Cxcr3, and Itgb1 triple-positive B cell subset, also expressing classical markers of the innate-like B-1 B cell population, served as the progenitor pool for Mzb1⁺ PCs. This subset accounted for the increase in IgG_2c production within BOS lung grafts. A genetic lack of Igs decreased BOS severity after LTx. In summary, we provide a detailed analysis of cell population changes during BOS. IgG⁺ PCs and their progenitors — an innate B cell subpopulation — are the major source of local Ab production and a significant contributor to BOS after LTx.

Small airways and airspace inflammation and injury distinguish lung histopathology in deployed military personnel from healthy and diseased lungs

The link between military deployment to Southwest Asia and Afghanistan and risk for lung disease, including bronchiolitis, is increasingly well-recognized. However, histopathologic features that distinguish deployment-related lung diseases from other diseases affecting the small airways and airspaces are uncertain. A computer-based scoring system was developed to characterize surgical lung biopsy findings in 65 soldiers with persistent respiratory symptoms following military deployment ('deployers'). Deployer lung biopsies were compared to those from eight patients with chronic hypersensitivity pneumonitis (cHP), 10 with smoking-related respiratory bronchiolitis, 11 with autoimmune or post-transplant obliterative bronchiolitis, and 10 normal donor lungs. Upper, middle, and lower lobe-specific findings in deployer samples were analyzed to inform optimum biopsy location choice for future patients.

Pathological entities that may affect the lungs and the myocardium. Evaluation with chest CT and cardiac MR

Certain entities may simultaneously involve the lungs and the myocardium. Knowing their cardiac and thoracic manifestations enhances the understanding of those conditions and increases awareness and suspicion for possible concurrent cardiothoracic involvement. Entities that can present with pulmonary and myocardial involvement include infiltrative diseases like sarcoidosis and amyloidosis, eosinophil-associated conditions including eosinophilic granulomatosis with polyangiitis (EGPA) and hypereosinophilic syndrome (HES), connective tissue diseases such as systemic sclerosis (SSc) and lupus erythematosus and genetic disorders like Fabry disease (FD). Lung involvement in sarcoidosis is almost universal. While cardiac involvement is less common, concurrent cardiothoracic involvement can often be seen. Pulmonary amyloidosis is more often a localized process and generally occurs separately from cardiac involvement, except for diffuse alveolar-septal amyloidosis. EGPA and HES can present with consolidative or ground glass opacities, cardiac inflammation and endomyocardial fibrosis. Manifestations of SSc include interstitial lung disease, pulmonary hypertension and cardiomyopathy. Lupus can present with serositis, pneumonitis and cardiac inflammation. FD causes left ventricular thickening and fibrosis, and small airways disease. This article aims to review the clinicopathological features of chest and cardiac involvement of these entities and describe their main findings on chest CT and cardiac MR.

IgA Antibodies Directed Against Citrullinated Protein Antigens Are Elevated in Patients With Idiopathic Pulmonary Fibrosis

BACKGROUND

The etiology of idiopathic pulmonary fibrosis (IPF) is unknown. Because it shares genetic, histopathologic, and radiographic features with the fibrosing interstitial lung disease seen in rheumatoid arthritis (RA), the goal of this study was to investigate RA-related autoantibodies in IPF.

METHODS

The study included patients with IPF from two separate cohorts at National Jewish Health and Brigham Women's Hospital (n = 181), general population control subjects (n = 160), and control subjects with disease (n = 86 [40 with RA-usual interstitial pneumonia and 46 with hypersensitivity pneumonitis]). Serum was tested for RA-associated antibodies (including IgG and IgA) to citrullinated protein antigens (ACPA). Lung tissue in 11 patients with IPF was examined for ectopic lymphoid aggregates.

RESULTS

An increased prevalence of ACPA positivity was found in two separate IPF cohorts. In particular, positivity for IgA-ACPA was increased in these two IPF cohorts compared with general population control subjects (21.3% and 24.8% vs 5.6%; P < .01). Patients with IPF were more likely to be IgA-ACPA-positive than IgG-ACPA-positive (23.2% vs 8.3%; P < .01), whereas patients with RA were more likely to be IgG-ACPA-positive than IgA-ACPA-positive (72.5% vs 52.5%; P = .04). There was a strong correlation between IgA-ACPA level and the number of ectopic lymphoid aggregates on lung histologic examination in IPF (r = 0.72; P = .01).

CONCLUSIONS

In this study, IgA-ACPA was elevated in patients with IPF and correlated with lymphoid aggregates in the lung, supporting the theory that IgA-ACPA may play a role in lung disease pathogenesis in a subset of individuals with IPF. Future studies are needed to determine whether this subset of ACPA-positive patients with IPF is distinct from patients with IPF but without antibodies.

Hospitalization Drug Regimen Changes in Geriatric Patients and Adherence to Modifications by General Practitioners in Primary Care

OBJECTIVES

To evaluate the overall rate of adherence by general practitioners (GPs) to treatment modifications suggested at discharge from hospital and to assess the way communication between secondary and primary care could be improved.

DESIGN

Observational prospective cohort study.

SETTING

Patients hospitalized from the emergency department to the acute geriatric care unit of a university hospital.

PARTICIPANTS

206 subjects with a mean age of 85 years.

MEASUREMENTS

Changes in drug regimen undertaken during hospitalization were collected with the associated justifications. Adherence at one month by GPs to treatment modifications was assessed as well as modifications implemented in primary care with their rationale in case of non-adherence. Community pharmacists' and GPs' opinions about quality of communication and information transfer at hospital-general practice interface were investigated.

RESULTS

5.5 ± 2.8 drug regimen changes were done per patient during hospitalization. The rate of adherence by GPs to treatment modifications suggested at discharge from hospital was 83%. In most cases, non-adherence by GPs to treatment modifications done during hospitalization was due to dosage adjustments, symptoms resolution but also worsening of symptoms. The last of which was particularly true for psychotropic drugs. All GPs received their patients' discharge letters but the timely dissemination still needs to be improved. Only 6.6% of community pharmacists were informed of treatment modifications done during their patients' hospitalization.

CONCLUSION

Our findings showed a successful rate of adherence by GPs to treatment modifications suggested at discharge from hospital, due to the fact that optimization was done in a collaborative way between geriatricians and hospital pharmacists and that justifications for drug regimen changes were systematically provided in discharge letters. Communication processes at the interface between secondary and primary care, particularly with community pharmacists, must be strengthened to improve seamless care.

Drug Prescription Including Interactions with Anticancer Treatments in the Elderly: A Global Approach

BACKGROUND

Consequences of inappropriate prescriptions and polymedication in patients suffering from cancer are beginning to be well documented. However, the methods used to evaluate these consequences are often discussed. Few studies evaluate the risk of interaction with anticancer drugs in elderly patients suffering from cancer.

OBJECTIVES

To describe the prevalence (i) of polypharmacy, (ii) of potentially inappropriate drug prescriptions and (iii) of drug interactions involving anticancer treatments, using a multiple reference tools.

DESIGN

A retrospective, cross-sectional, multicenter study performed from January to December 2012.

PARTICIPANTS

Patients aged 65 years or older suffering from cancer presented at the oncogeriatric multidisciplinary meeting.

MEASUREMENTS

Polymedication (>6 drugs), potentially inappropriate prescriptions and drug interactions involving anticancer treatment were analyzed in combination with explicit and implicit criteria within a global approach.

RESULTS

Among the 106 patients included in this study, polypharmacy was present in 60.4% of cases, potentially inappropriate drug prescription in 63.1% and drug interactions in 16% of case, of which 47% involved anti-cancer treatments. Twenty-seven major drug interactions were identified and eight interactions involved chemotherapy.

CONCLUSION

Polymedication, inappropriate prescribing and drug interactions involving anti-cancer drugs are common and largely underestimated in elderly cancer patients.

Relationship between gene expression and lung function in Idiopathic Interstitial Pneumonias

Background

Idiopathic interstitial pneumonias (IIPs) are a group of heterogeneous, somewhat unpredictable diseases characterized by progressive scarring of the interstitium. Since lung function is a key determinant of survival, we reasoned that the transcriptional profile in IIP lung tissue would be associated with measures of lung function, and could enhance prognostic approaches to IIPs.

Results

Using gene expression profiling of 167 lung tissue specimens with IIP diagnosis and 50 control lungs, we identified genes whose expression is associated with changes in lung function (% predicted FVC and % predicted D_LCO) modeled as categorical (severe vs mild disease) or continuous variables while adjusting for smoking status and IIP subtype; false discovery rate (FDR) approach was used to correct for multiple comparisons. This analysis identified 58 transcripts that are associated with mild vs severe disease (categorical analysis), including those with established role in fibrosis (ADAMTS4, ADAMTS9, AGER, HIF-1α, SERPINA3, SERPINE2, and SELE) as well as novel IIP candidate genes such as rhotekin 2 (RTKN2) and peptidase inhibitor 15 (PI15). Protein-protein interactome analysis of 553 genes whose expression is significantly associated with lung function when modeled as continuous variables demonstrates that more severe presentation of IIPs is characterized by an increase in cell cycle progression and apoptosis, increased hypoxia, and dampened innate immune response. Our findings were validated in an independent cohort of 131 IIPs and 40 controls at the mRNA level and for one gene (RTKN2) at the protein level by immunohistochemistry in a subset of samples.

Conclusions

We identified commonalities and differences in gene expression among different subtypes of IIPs. Disease progression, as characterized by lower measures of FVC and D_LCO, results in marked changes in expression of novel and established genes and pathways involved in IIPs. These genes and pathways represent strong candidates for biomarker studies and potential therapeutic targets for IIP severity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-2102-3) contains supplementary material, which is available to authorized users.

Role of IL-18 in second-hand smoke-induced emphysema

Chronic second-hand smoke (SHS) exposure comprises the main risk factor for nonsmokers to develop chronic obstructive pulmonary disease (COPD). However, the mechanisms behind the chronic inflammation and lung destruction remain incompletely understood. In this study, we show that chronic exposure of Sprague-Dawley rats to SHS results in a significant increase of proinflammatory cytokine IL-18 and chemokine (C-C motif) ligand 5 in the bronchoalveolar lavage fluid (BALF) and a significant decrease of vascular endothelial growth factor (VEGF) in the lung tissue. SHS exposure resulted in progressive alveolar airspace enlargement, cell death, pulmonary vessel loss, vessel muscularization, collagen deposition, and right ventricular hypertrophy. Alveolar macrophages displayed a foamy phenotype and a decreased expression of the natural inhibitor of IL-18, namely, IL-18 binding protein (IL-18BP). Moreover, IL-18 down-regulated the expression of VEGF receptor-1 and VEGFR receptor-2, and induced apoptosis in pulmonary microvascular endothelial cells in vitro. We also observed a trend toward increased concentrations of IL-18 in the BALF of patients with COPD. Our findings suggest that IL-18-mediated endothelial cell death may contribute to vascular destruction and disappearance in SHS-induced COPD. Moreover, IL-18 and IL-18BP are potential new targets for therapeutics.

Expression of cilium-associated genes defines novel molecular subtypes of idiopathic pulmonary fibrosis

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.

Interleukin 32 promotes angiogenesis: a new role for a versatile cytokine. (P6266)

IL-32 is a multi-faceted cytokine with roles in infection, autoimmunity and cancer. It aggravates inflammation, inhibits virus propagation and acts as a critical regulator of endothelial cell (EC) function. We now discovered that IL-32 also possesses angiogenic properties. The hyperproliferative EC of pulmonary hypertension and glioblastoma multiforme exhibited a markedly increased abundance of IL-32, and the cytokine colocalized with integrin αVβ3. In vitro, VEGF receptor blockade resulted in hyperproliferation of EC and a 3.4-fold increase in IL-32. When IL-32 was silenced by siRNA, the proliferation of adult and fetal EC was reduced (change in cell number +58% vs -15%). Mechanistic studies revealed that siIL-32-transfected EC produced 3-fold more activin A and angiopoietin 2, but 61% less NO, whereas neither apoptosis nor the abundance of VEGF or TGF-β were affected. Interestingly, pre-treatment with IFNγ was required to render EC responsive to exogenous IL-32γ. To obtain in vivo evidence for these angiogenic effects, we injected mice with matrigel plugs loaded with IL-32γ, VEGF or vehicle, and performed CD31- and H&E-staining after 14d. As anticipated, 25 ng/ml of VEGF increased neocapillarization 8-fold, but unexpectedly the effect of 100 ng/ml IL-32γ was even stronger (8.5-fold). In summary, we add VEGF-independent angiogenic properties to the portfolio of IL-32, implicating a role in pulmonary hypertension and neoplastic diseases that is possibly exerted via αVβ3.

LUNG INFLATION WITH DIRECT INJECTION OF AGAROSE: A TECHNIQUE FOR SIMULTANEOUS MOLECULAR AND MORPHOMETRIC MEASUREMENTS

The usual methods for preparing lungs for morphologic study involve the instillation of fixatives that modifyproteins and RNA such that the tissue is unsuitable for molecular studies. To develop a technique suitable for molecular studies, pieces of adult rat lungs were infiltrated with agarose, glutaraldehyde, or paraformaldehyde and the consistency of alveolar inflation was compared to lungs inflated with 10% formalin. Only direct injection with 1% agarose resulted in comparable inflation of lung tissue and preserved RNA and protein. Thus, this technique enables simultaneous molecular and morphometric analysis of the lung on small pieces of lung tissue in heterogeneous lung diseases.

Immunopathology of chronic rhinosinusitis in young children

OBJECTIVE

Previous investigation demonstrated predominantly lymphocytic inflammation in sinus mucosa of young children with chronic rhinosinusitis (CRS) rather than eosinophilic inflammation typical of adult CRS. Immunohistopathological study was undertaken to define further the cellular response in pediatric CRS.

STUDY DESIGN

Maxillary mucosal biopsies from children and adults with CRS were stained for CD3 (T lymphocytes), CD4 (helper T lymphocytes), CD8 (cytotoxic T lymphocytes), CD20 (B lymphocytes), CD68 (monocytes/macrophages), CD56 (natural killer cells), kappa and lambda (plasma cells), and myeloperoxidase (MPO; neutrophils).

RESULTS

Nineteen children with CRS (median age, 3.0 years; range, 1.4-8.2 years) had more CD8+, MPO+, and CD68+ cells (P < or = .03) and a trend toward more CD3+ and CD4+ cells (P = .06) in their epithelium and more CD20+, kappa+ and lambda+, MPO+, and CD68+ cells (P < or = .05) and a trend toward more CD4+ cells (P = .06) in their submucosa compared with adult control subjects. Immunostains from children with positive sinus cultures were similar to those with negative cultures except for more MPO+ cells in the submucosa (P = .04).

CONCLUSION

The inflammatory response of young children with CRS is characterized by a mixed lymphocyte population, macrophages, and neutrophils. Differences between pediatric and adult CRS suggest differing pathogenic mechanisms or progression in the inflammatory response with protracted disease.

Absence of T cells confers increased pulmonary arterial hypertension and vascular remodeling

RATIONALE

Severe pulmonary arterial hypertension (SPH) is a frequently lethal condition characterized by pulmonary vascular remodeling and right heart strain or failure. SPH is also often associated with autoimmune and collagen vascular disorders.

OBJECTIVES

To study the effects of T cells on the development of experimental SPH.

METHODS

Athymic nude rats lacking T cells were treated with a single subcutaneous injection of vascular endothelial growth factor (VEGF) receptor blocker SU5416 (20 mg/kg) to induce pulmonary vascular endothelial cell apoptosis. Immunohistochemical analysis and IL-4 levels of the lung tissue were performed. Cell death and proliferation were assessed by Western blot and immunohistochemistry.

MEASUREMENTS AND MAIN RESULTS

In contrast to SU5416-treated euthymic rats that develop SPH only in combination with chronic hypoxia, athymic nude rats developed SPH and vascular remodeling (similar to clinical SPH) at normoxic conditions as demonstrated by measurements of pulmonary artery pressure and right ventricle hypertrophy. Pulmonary arterioles became occluded with proliferating endothelial cells and were surrounded by mast cells, B cells, and macrophages. IL-4, proliferating cell nuclear antigen, and collagen type I levels were markedly increased in SU5416-treated athymic rat lungs. Antibody deposition was noted along the vascular endothelium in rats with SPH. Finally, protection from SPH was conferred by immune challenge with spleen cells from euthymic nude rats.

CONCLUSIONS

These studies demonstrate the importance of a complete, intact immune system in protecting against pulmonary angioproliferation in this new model of SPH as well as the importance of intact VEGF receptor signaling for lung endothelial cell homeostasis.

Prostacyclin prevents pulmonary endothelial cell apoptosis induced by cigarette smoke

RATIONALE

Impaired endothelial cell-dependent vasodilation, inflammation, apoptosis, and proliferation are manifestations of endothelial dysfunction in chronic obstructive pulmonary disease (COPD). Prostacyclin (PGI(2)) is a major product of the cyclooxygenase pathway with potent vasodilatory and antimitogenic properties and may be relevant to endothelial dysfunction in COPD.

OBJECTIVES

To determine if PGI(2) expression is altered in smoking-related lung disease and if it may be protective in COPD-associated endothelial dysfunction.

METHODS

We evaluated, by immunohistochemistry, Western blotting, and polymerase chain reaction, human emphysema tissue compared with normal tissue for expression of prostacyclin synthase (PGI(2)S). We examined the effects of cigarette smoke extract (CSE) and aldehyde components on eicosanoid expression in primary human pulmonary microvascular endothelial cells. Finally, we used a murine model of lung-specific PGI(2)S overexpression and in vitro studies to determine if PGI(2) expression has protective effects on cigarette smoke-induced endothelial apoptosis.

MEASUREMENTS AND MAIN RESULTS

Human emphysema lung tissue exhibited lower PGI(2)S expression within the pulmonary endothelium than in normal lung. In vitro studies demonstrated that CSE, and in particular the alpha,beta unsaturated aldehyde acrolein, suppressed PGI(2)S gene expression, whereas CSE significantly induced the upstream mediators COX-2 and cytosolic phospholipase A2 in human pulmonary microvascular endothelial cells. Mice with lung-specific PGI(2)S overexpression exhibited less endothelial apoptosis after chronic smoke exposure. In vitro, iloprost exhibited protective effects on CSE-induced apoptosis.

CONCLUSIONS

PGI(2) has protective effects in the pulmonary vasculature after acute and chronic cigarette smoke exposure. An imbalance in eicosanoid expression may be important to COPD-associated endothelial dysfunction.

Simvastatin causes endothelial cell apoptosis and attenuates severe pulmonary hypertension

Severe pulmonary hypertension (SPH) is characterized by precapillary arteriolar lumen obliteration, dramatic right ventricular hypertrophy, and pericardial effusion. Our recently published rat model of SPH recapitulates major components of the human disease. We used this model to develop new treatment strategies for SPH. SPH in rats was induced using VEGF receptor blockade in combination with chronic hypoxia. A large variety of drugs used in this study, including anticancer drugs (cyclophosphamide and paclitaxel), the angiotensin-converting enzyme inhibitor lisinopril, the antiangiogenic agent thalidomide, and the peroxisome proliferator-actived receptor-gamma agonist PGJ2, failed to decrease mean pulmonary artery pressure (PAP) or right ventricular hypertrophy. In contrast, treatment of rats with established SPH with simvastatin markedly reduced mean PAP and right ventricular hypertrophy, and this reduction was associated with caspase-3 activation and pulmonary microvascular endothelial cell apoptosis. Simvastatin partially restored caveolin-1, caveolin-2, and phospho-caveolin expression in vessel walls. In rat primary pulmonary microvascular endothelial cells, simvastatin induced caspase 3 activation and Rac 1 expression while suppressing Rho A and attenuated levels of Akt and ERK phosphorylation. We conclude that simvastatin is effective in inducing apoptosis in hyperproliferative pulmonary vascular lesions and could be considered as a potential drug for treatment of human SPH.

A protocol for the handling of tissue obtained by operative lung biopsy: recommendations of the chILD pathology co-operative group

This is the first of a series on pediatric pulmonary disease that will appear as Perspectives in Pediatric Pathology over the coming months. The series will include practical issues, such as this protocol for handling lung biopsies and another on bronchoalveolar lavage in childhood, as well as reviews of advances in various areas in pediatric pulmonary pathology. It has been 11 years since the last Perspectives on pulmonary disease. Much has happened since then in this area, and this collection will highlight some emerging and rapidly advancing areas in pediatric lung disease. These will include a review of molecular mechanisms of lung development, and another of mechanisms of pulmonary vascular development. The surfactant system and its disorders, as well as recent advances in the biology of the pulmonary neuroendocrine system and mechanisms of respiratory viral disease, will be addressed. Articles on pulmonary hypertension, pulmonary neoplasia, and pediatric lung transplantation, with their implications for the pediatric pathologist, are also planned. The contributors to this series are a diverse group with special interests and expertise in these areas. As Dr. William Thurlbeck noted in his foreword to the previous volume, Pulmonary Disease, volume 18 of Perspectives in Pediatric Pathology, pediatric pathology had been largely concerned with phenomenology, rather than with mechanisms, model systems, and experimental investigation. I think he would have been pleased to see the changes that have occurred over the past 10 years in pediatric lung biology and pathology in particular, because these were particularly favored interests of his later years.

Pulmonary Capillaritis in Lung Transplant Recipients: Treatment and Effect on Allograft Function

The clinical outcomes of lung transplant recipients presenting with post-transplant pulmonary capillaritis have not been well described. We retrospectively reviewed 40 cases of biopsy-proven pulmonary capillaritis in lung transplant recipients. Patients presented with a clinical syndrome characterized by dyspnea, hypoxemia, abnormal chest X-ray, and a decrease in forced expiratory volume in 1 second (FEV1); 25% presented with hemoptysis, and 18% with fulminant respiratory failure. Therapy with intravenous corticosteroids resulted in clinical improvement in 17 cases (43%). A response to plasmapheresis was seen in 12 (67%) of 18 cases refractory to corticosteroids. There were 5 deaths within 3 months of diagnosis. Nine (82%) of 11 lung transplant recipients who presented with capillaritis within 4 weeks post-transplant were alive at 1 year; all but 1 patient achieved expected percent predicted FEV1 values. Only 3 (14%) of 21 who presented with capillaritis > 1 month after transplant had a >20% decrease in the FEV1 after 12 months. These results suggest that post-transplant pulmonary capillaritis is (1) likely a form of acute allograft rejection clinically and histologically distinct from typical acute rejection, (2) less responsive to corticosteroid therapy than typical acute rejection, and (3) not associated with long-term adverse effects on allograft function.

Radiologic and pathologic features of bronchiolitis

OBJECTIVE

The purpose of this article is to describe and illustrate the clinical, pathologic, and imaging features of the inflammatory and fibrotic forms of bronchiolitis. The CT features presented in this article represent the typical features associated with each entity.

CONCLUSION

Direct signs of bronchiolitis include centrilobular nodules and tree-in-bud pattern. Indirect signs include mosaic attenuation and air trapping. Although classic examples of each entity exist, there can be substantial overlap in the appearances, and distinguishing among these entities is not always possible. When high-resolution CT features overlap, clinical details will usually help to narrow the differential diagnosis.

Treatment of severe pulmonary hypertension: a bradykinin receptor 2 agonist B9972 causes reduction of pulmonary artery pressure and right ventricular hypertrophy

Bradykinin is an important modulator of endothelial cell function and has also a powerful cardioprotective effect. Here we report that treatment of severely pulmonary hypertensive rats (that recapitulate several of the physiological and pathological characteristics of the human pulmonary vascular disease, including dramatic right ventricular hypertrophy, pericardial effusion and death) with a newly synthesized long-acting bradykinin B2 receptor agonist B9972 caused reduction of the pulmonary artery pressure (PAP=51+/-2.0 versus 68+/-2.8 of untreated animals) and of right ventricular hypertrophy (Rv/Lv+S=0.55+/-0.02 versus 0.73+/-0.03 of untreated rats) and activation of Akt. Long-term stimulation with B9972 in our animal model of SPH resulted in decreased expression of the B2 receptor in lung vasculature. Treatment with B9972 decreased the number of plexiform lesions in the lungs by inducing cell apoptosis in the obliterated vessels and by restoring caveolin-1 expression. B9972 also promoted eNOS activation. In vitro B9972 caused activation of caspase-3 as well as Erk and induction of prostacyclin production in rat pulmonary microvascular EC. Taken together our data suggest that a stable bradykinin B2 agonist B9972 demonstrates the capacity to reduce severe pulmonary hypertension, right ventricular hypertrophy and induce apoptosis of hyperproliferative cells in pre-capillary pulmonary arterioles.

High-resolution computed tomography features of nonspecific interstitial pneumonia and usual interstitial pneumonia

OBJECTIVE

To assess the accuracy of high-resolution computed tomography (HRCT) in the diagnosis of nonspecific interstitial pneumonia (NSIP). We hypothesized that the computed tomography (CT) features of NSIP could be distinguished from those of usual interstitial pneumonia (UIP).

METHODS

The HRCT images of 47 patients with surgical lung biopsy-proven NSIP (n = 25) and UIP (n = 22) were independently reviewed by 2 thoracic radiologists. Predominant imaging patterns, most likely diagnosis, and diagnostic level of confidence were recorded. A confident HRCT diagnosis of NSIP was based on the presence of spatially uniform, bilateral, basal-predominant ground-glass and/or reticular opacities with little if any honeycombing, whereas UIP was confidently diagnosed if a spatially inhomogeneous, bilateral, peripheral, basal-predominant pattern of reticular opacities and honeycombing with little if any ground-glass attenuation was identified.

RESULTS

A predominant pattern of ground-glass and/or reticular opacity with minimal to no honeycombing was demonstrated in 48 (96%) of 50 readings in patients with NSIP. Conversely, the presence of honeycombing as a predominant feature had a predictive value of 90% for UIP (P < 0.001). Usual interstitial pneumonia was more likely than NSIP to be subpleural and patchy (P < 0.001). A confident CT diagnosis of NSIP and UIP was correct in 73% and 88% of cases, respectively. The correctness of a CT diagnosis made at intermediate or high confidence was 68% and 88%, respectively. The kappa value for distinction of NSIP from UIP was 0.72.

CONCLUSION

In contrast to previous reports, NSIP can be separated from UIP in most cases. The presence of honeycombing as a predominant imaging finding is highly specific for UIP and can be used to differentiate it from NSIP, particularly when the distribution is patchy and subpleural predominant. The presence of predominant ground-glass and reticular opacity is highly characteristic of NSIP, but there is a subset of patients with UIP who have this pattern and may require biopsy for differentiation from NSIP.

Progression of asthma in childhood

In general, asthma runs a variable course. However, there are children with asthma who are at risk for progressive disease that can lead to failure to attain peak lung growth and eventually can result in clinical and functional impairment. We present a case of a 14-year-old girl who has demonstrated a deterioration in lung function at least in the past 6 years. This has been associated with increasing medication requirements, including chronic oral corticosteroid and a steroid-sparing medication, the presence of comorbidities, and the occurrence of frequent exacerbations. The patient has evidence of airway inflammation and remodeling based on biomarkers and biopsy findings. It remains a challenge to determine patients at risk for irreversible airflow obstruction, presumably a result of airway remodeling. Histopathologic studies from biopsy samples provide the best evidence for this. However, bronchoscopy and biopsy require technical expertise and cannot be routinely used. Clinically, once a patient increases medication requirements, this should serve as a marker of disease progression. Biomarkers of airway inflammation such as exhaled nitric oxide, exhaled breath condensates, and induced sputum analysis may have the potential to monitor disease progression. Additional efforts are necessary to understand the mechanisms involved in this phenomenon and to discover specific modalities of treatment to target the structural changes of airway remodeling.

Low-voltage-activated (T-type) calcium channels control proliferation of human pulmonary artery myocytes

While Ca2+ influx is essential for activation of the cell cycle machinery, the processes that regulate Ca2+ influx in this context have not been fully elucidated. Electrophysiological and molecular studies have identified multiple Ca2+ channel genes expressed in mammalian cells. Ca(v)3.x gene family members, encoding low voltage-activated (LVA) or T-type channels, were first identified in the central nervous system and subsequently in non-neuronal tissue. Reports of a potential role for T-type Ca2+ channels in controlling cell proliferation conflict. The present study tested the hypothesis that T-type Ca2+ channels, encoded by Ca(v)3.x genes, control pulmonary artery smooth muscle cell proliferation and cell cycle progression. Using quantitative RT/PCR, immunocytochemistry, and immunohistochemistry we found that Ca(v)3.1 was the predominant Ca(v)3.x channel expressed in early passage human pulmonary artery smooth muscle cells in vitro and in the media of human pulmonary arteries, in vivo. Selective blockade of Ca(v)3.1 expression with small interfering RNA (siRNA) and pharmacological blockade of T-type channels completely inhibited proliferation in response to 5% serum and prevented cell cycle entry. These studies establish that T-type voltage-operated Ca2+ channels are required for cell cycle progression and proliferation of human PA SMC.

Pathology of pulmonary hypertension

This article briefly discusses the traditional concepts of severe pulmonary hypertension and then details how the concept of severe pulmonary hypertension has moved from a vasoconstrictive to an angioproliferative disorder.

Oxidative stress in severe pulmonary hypertension

Severe pulmonary hypertension (PH) occurs in a primary or "unexplained" form and in a group of secondary forms associated with a number of diseases. Because the lung tissue from patients with severe PH demonstrates complex vascular lesions, which contain inflammatory cells, we wondered whether the lung tissue from patients with severe PH was "under oxidative stress." We used immunohistochemistry to localize nitrotyrosine and 8-hydroxy guanosine in the lung tissue sections from patients with primary and secondary PH. In some lung tissue extracts, the eicosanoid metabolites 5-oxo-eicosatetraenoic acid, leukotriene B4 5-hydroxyeicosatetraenoic acid (HETE), 12-HETE, and 15-HETE were measured using mass spectroscopy, and superoxide dismutase amount and activity were measured. Nitrotyrosine expression was ubiquitous in all PH lungs, and 5-oxo-eicosatetraenoic acid and HETE levels were elevated in the lungs of patients with severe PH but not in those lungs that were from the patients with severe PH treated chronically with prostacyclin. We conclude that indeed the lungs from patients with severe PH are under oxidative stress and that chronic prostacyclin infusion has an antiinflammatory effect on the lung tissue.

Histopathology of severe childhood asthma: a case series

BACKGROUND

To date, little has been published describing the pathology of severe childhood asthma. The currently accepted model of asthma holds that persistent airway inflammation leads to various symptoms of asthma, airway hyperresponsiveness, and airway remodeling that ultimately results in permanent loss of lung function.

METHODS

Evaluation of six children referred to the National Jewish Medical and Research Center with difficult-to-control asthma, despite aggressive anti-inflammatory therapy, who underwent bronchoscopy with endobronchial biopsy to better characterize their disease.

RESULTS

In every case, endobronchial biopsies revealed changes consistent with airway remodeling characterized by thickening of the basement membrane, smooth-muscle hypertrophy, with varying degrees of goblet-cell and submucous gland hyperplasia. The degree of subbasement membrane thickening did not appear to correlate with baseline FEV(1), ultimate FEV(1) following aggressive therapy, or lability in lung function. In five of six cases, there was minimal to no histologic evidence for airway inflammation with mild and patchy submucosal lymphocytic infiltration noted; eosinophils and neutrophils were not present. Further, the majority of the patients achieved normal FEV(1) values despite significant subbasement membrane thickening, counter to the current beliefs regarding airway remodeling and irreversible loss of lung function.

CONCLUSIONS

This case report highlights some of the shortcomings of the current inflammatory paradigm for severe asthma. Despite little evidence of ongoing airway inflammation, many of the subjects displayed significant lung function lability. The lack of inflammation argues against steroid resistance at a cellular level, although it could be argued that inflammation may have been distal to the site sampled. Additionally, normal to nearly normal lung function was achieved despite the presence of significant remodeling. These findings suggest the need to look beyond inflammation to fully treat severe asthma and ultimately alter its progression.

gamma-Catenin expression is reduced or absent in a subset of human lung cancers and re-expression inhibits transformed cell growth

Lung cancer is a heterogeneous disease categorized into multiple subtypes of cancers which likely arise from distinct patterns of genetic alterations and disruptions. Precedent exists for a role of beta-catenin, a downstream component of the Wnt signaling pathway that serves as a transcriptional co-activator with TCF/LEF, in several human cancers including colon carcinomas. In this study, we observed that beta-catenin was highly and uniformly expressed in a panel of NSCLC cell lines and primary lung tumors. By contrast, gamma-catenin was weakly expressed or absent in several NSCLC cell lines and immunohistochemical analysis of primary NSCLC tumors revealed negligible to weak gamma-catenin staining in approximately 30% of the specimens. Treatment of NSCLC cells expressing reduced gamma-catenin protein with 5-aza-2'-deoxycytidine (5aza2dc), a DNA methylation inhibitor, or trichostatin A (TSA), a histone deacetylase inhibitor, increased gamma-catenin protein content in NSCLC cells with low gamma-catenin expression. Significantly, the activity of a beta-catenin/TCF-dependent luciferase reporter was markedly elevated in the NSCLC cell lines that underexpressed gamma-catenin relative to those lines that highly expressed gamma-catenin. Moreover, transfection of these cells with a gamma-catenin expression plasmid reduced the elevated TCF activity by 85% and strongly inhibited cell growth on tissue culture plastic as well as anchorage-independent growth in soft agar. This study shows that gamma-catenin can function as an inhibitor of beta-catenin/TCF-dependent gene transcription and highlights gamma-catenin as a potentially novel tumor suppressor protein in a subset of human NSCLC cancers.

Analysis of nitric oxide synthase and nitrotyrosine expression in human pulmonary tuberculosis

The role of nitric oxide (NO) in the host-defense against human tuberculosis (TB) is controversial. Although experimental evidence indicates that NO may play an important role in controlling TB, its expression in human tuberculous lungs has not been systematically characterized. We therefore investigated the expression of NO synthases (NOS) and of nitrotyrosine, the latter a marker of NO expression, in surgically resected lungs of eight patients with TB. Immunohistochemical and morphometric analyses revealed that, compared with control subjects, inducible NOS, endothelial NOS, and nitrotyrosine, but not neuronal NOS, were significantly elevated in the inflammatory zone of the tuberculous granulomas, and in the nongranulomatous pneumonitis zone. Tumor necrosis factor-alpha (TNF-alpha) was also significantly increased in tuberculous lungs and was principally localized to the necrotic, and to a lesser extent, the inflammatory and fibrotic areas of the granulomas. The NOS isoforms, nitrotyrosine, and TNF-alpha were expressed by the epithelioid macrophages and giant cells within the granulomas and in alveolar macrophages and epithelial cells in pneumonitis areas. This descriptive study provides evidence that in human TB, NOS isoenzymes and NO are present in specialized areas of the tuberculous granulomas; their precise role in human TB remains to be determined.

Lymphocyte activation in the lungs of SP-D null mice

Surfactant protein D (SP-D) appears to play an important role in regulating local pulmonary inflammatory responses to pathogens. There is also in vitro evidence that SP-D may suppress local T cell responses. However, the role of SP-D in regulating T cell responses directly in the lung has not been previously evaluated in vivo. SP-D(-)(/-) mice demonstrate peribronchial and perivascular accumulations of lymphocytes. Therefore, we investigated the functional status and abundance of intrapulmonary lymphocytes in SP-D(-)(/-) mice. By morphometric analysis, SP-D(-)(/-) mice demonstrated increased numbers of airway- and vessel-associated lymphocytes without increases in interstitial lymphocytes. There was increased proliferative activity of lymphocytes isolated by enzymatic disassociation of minced lung. Flow cytometry was used to determine the number and functional activation status of intrapulmonary CD4(+) and CD8(+) T cells, as well as B cells and NK cells. Cytokine expression patterns in lung tissues were evaluated using RNase protection assays, reverse transcriptase/polymerase chain reaction, and enzyme-linked immunosorbent assay. There was marked T cell activation in the lungs of SP-D(-)(/-) mice, as reflected by an increased percentage of both CD4(+) and CD8(+) T cells expressing CD69 and CD25. BAL CD4 lymphocytes were increased and the fraction expressing CD69 was also increased. Although there were increases in BAL CD8 lymphocytes, apparent increases in CD69-positive CD8 lymphocytes did not reach statistical significance. In contrast, splenic T cells were not activated in SPD(-)(/-) mice. Of the proinflammatory cytokines evaluated, only interleukin (IL)-12 and IL-6 expression were consistently upregulated in the lungs of SPD(-)(/-) mice. Increased IL-2 expression was apparent but did not reach statistical significance. We conclude that the lack of local pulmonary production of SP-D leads to a state of persistent T cell activation, possibly in response to exogenous antigens. This study therefore provides further evidence of the important local immunoregulatory role of SP-D in vivo.

Janus face of vascular endothelial growth factor: the obligatory survival factor for lung vascular endothelium controls precapillary artery remodeling in severe pulmonary hypertension

Vascular endothelial growth factor (VEGF) plays a central role in the life and death of pulmonary vascular endothelial cells. Treatment of neonatal or adult rats with a VEGF receptor blocker destroys lung capillaries by inducing endothelial cell apoptosis and causes emphysema. Human lung tissue samples from patients with endstage emphysema have decreased levels of VEGF messenger RNA and protein and have decreased expression of kinase insert domain-containing receptor (VEGF receptor II). These decreases are associated with a high rate of alveolar septal cell apoptosis, indicating perhaps that decreased VEGF and kinase insert domain-containing receptor expression impairs endothelial cell survival in emphysematous lungs. Combination of VEGF receptor blockade with chronic hypoxia (3-wk exposure) results in obliteration of small precapillary pulmonary arteries by proliferating endothelial cells, severe pulmonary hypertension, and death caused by right-side heart failure. We propose that 1) VEGF receptor blockade causes endothelial cell apoptosis, 2) hypoxic vasoconstriction (shear stress) selects apoptosis-resistant endothelial cells that proliferate and obliterate the lumen, and 3) the vascular remodeling observed is relevant to the structural alterations that characterize severe pulmonary hypertension (including primary pulmonary hypertension) in humans. The endovascular cell growth in human disease and in our model exhibits some similarities with neoplastic cell growth. Chemotherapy strategies can now be employed in the animal model in an attempt to treat established vascular-obliterative lung disease.