Haemosiderin-laden macrophages in the bronchoalveolar lavage fluid of patients with diffuse alveolar damage

Dynamic shifts in lung cytokine patterns in post-COVID-19 interstitial lung disease patients: a pilot study

Introduction

The pathogenesis of post-COVID interstitial lung disease, marked by lung tissue scarring and functional decline, remains largely unknown.

Objectives

We aimed to elucidate the temporal cytokine/chemokine changes in bronchoalveolar lavage (BAL) from patients with post-COVID interstitial lung disease to uncover potential immune drivers of pulmonary complications.

Design

We evaluated 16 females diagnosed with post-COVID interstitial lung disease, originating from moderate to severe cases during the second epidemic wave in the Autumn of 2020, treated at the Pneumology Department of the Arad County Clinical Hospital, Romania. Their inflammatory response over time was compared to a control group.

Methods

A total of 48 BAL samples were collected over three intervals (1, 3, and 6 months) and underwent cytology, gene, and protein expression analyses for pro/anti-inflammatory lung cytokines and chemokines using reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay.

Results

One month after infection, there were significant increases in the levels of IL-6 and IL-8. These levels decreased gradually over the course of 6 months but were still higher than those seen in control. Interferon-gamma and tumor necrosis factor alpha exhibited similar patterns. Persistent elevations were found in IL-10, IL-13, and pro-fibrotic M2 macrophages' chemokines (CCL13 and CCL18) for 6 months. Furthermore, pronounced neutrophilia was observed at 1 month post-COVID, highlighting persistent inflammation and lung damage. Neutrophil efferocytosis, aiding inflammation resolution and tissue repair, was evident at the 1-month time interval. A notable time-dependent reduction in CD28 was also noticed.

Conclusion

Our research provides insight into the immunological processes that may lead to the fibrotic changes noted in the lungs following COVID-19.

Role of bronchoscopy for respiratory involvement in granulomatosis with polyangiitis and microscopic polyangiitis

Objectives

This study describes data from bronchoscopy performed at the diagnosis of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Methods

We conducted a retrospective study between 2004 and 2019 in patients aged >18 years with a diagnosis of microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA) who underwent bronchoscopy at onset of the disease. We collected bronchoalveolar lavage (BAL) and histological findings obtained during bronchoscopy.

Results

274 patients with AAV were identified. Among 92 bronchoscopies, 62 were performed at diagnosis, and 58 procedures were finally analysed. Cough was more frequent in patients with MPA than GPA (p=0.02). The presence of endobronchial lesions (24.1%) was found to be significantly associated with GPA (p<0.0001) and proteinase 3-ANCA (p=0.01). The most frequent endobronchial lesions were inflammation and hyperaemia of the bronchial mucosa (50%), followed by stenoses (28%), ulcerations (21%) and mass-like granulomatosis (7%). The diagnostic yield of bronchial biopsies was useful for visible lesions (66.6% versus 0%; p=0.006). On BAL, diffuse alveolar haemorrhage (DAH) was detected in 31 (53.4%) patients and was more frequent in MPA patients (70.4% versus 38.7%; p=0.016). In 16.1% of DAH cases, BAL confirmed the diagnosis despite the absence of clinical or biological arguments. The incidence of microbial infections on BAL (38%) was similar between MPA and GPA (p=0.54).

Conclusion

Bronchoscopy is an informative procedure at the onset of AAV disease in patients with respiratory manifestations. Endobronchial lesions are more frequently found in GPA and should be biopsied. BAL can be used to confirm DAH or diagnose superadded infection.

Hemosiderin-Laden Macrophages in Bronchoalveolar Lavage Samples of Children with Bronchopulmonary Dysplasia

OBJECTIVES

To evaluate the prevalence of hemosiderin-laden macrophages in children with bronchopulmonary dysplasia (BPD) and assess for an association between hemosiderin-laden macrophages and pulmonary arterial hypertension.

STUDY DESIGN

Retrospective case-control study of infants and children with and without BPD who underwent bronchoscopy with bronchoalveolar lavage (BAL) the at Children's Hospital of Philadelphia between 2012 and 2021.

RESULTS

BAL from 205 children with BPD and 106 controls without BPD matched for tracheostomy, infection, and age were reviewed for hemosiderin-laden macrophages. Seventy-one individuals (34.6%) with BPD had a BAL with 10% or more hemosiderin-laden macrophages compared with 3 (2.8%) controls (P < .0001; OR, 18.19; 95% CI, 5.57-59.41). Patients with pulmonary hypertension by echocardiogram (P = .04; OR, 3.69; 95% CI, 1.05-12.96) or an elevated mean pulmonary artery pressure during cardiac catheterization, r_s (14) = 0.56, P = .04, were more likely to have elevated hemosiderin-laden macrophages on BAL samples less than 60 days from bronchoscopy. After adjusting for birth weight, gestational age, BPD grade, and age at the time of bronchoscopy using logistic regression, pulmonary hypertension was associated with a higher odds of hemosiderin-laden macrophages of 10% or more (P = .02; OR, 6.37; 95% CI, 1.28-31.87). No association was observed between hemosiderin-laden macrophages and sex, race, gestational age, birth weight, tracheostomy, or infectious studies.

CONCLUSIONS

This retrospective study revealed increased hemosiderin-laden macrophages in BAL samples from patients with BPD and a significant association with pulmonary arterial hypertension. It is unclear whether elevated hemosiderin-laden macrophages within BPD contributes to the pathogenesis of lung and pulmonary vascular disease or is simply a biomarker of pulmonary arterial hypertension.

Selected severe &#8222;haematological&#8220; syndromes in adult intensive care patients

Haemophagocytic syndrome, diffuse alveolar haemorrhage, catastrophic antiphospholipid syndrome and various types of thrombotic microangiopathies are rare conditions with significant morbidity and mortality. A common feature is late diagnosis, which can affect the success of treatment. The aim of this review article is to summarize the basic diagnostic and therapeutic steps of the present subpopulation of critically ill patients.

Celiac disease and idiopathic pulmonary hemosiderosis: A literature review of the Lane-Hamilton Syndrome

Lane-Hamilton syndrome (LHS) presents a medical emergency, with 14% mortality due to Idiopathic Pulmonary Hemosiderosis (IPH) in acute phase. Despite the clinical severity of this entity, there has been no published review in the international literature, resulting in lack of awareness and delayed diagnosis.A rigorous search of international databases yielded a total of 80 LHS cases from January 1971 to August 2020. We analyzed 44 children (8.56±4.72years, 21boys) and 36 adults (33.61±13.41years, 12men), to present the clinical manifestations, radiological and immunological pattern, therapeutic approaches and outcome of LHS. We also elaborated on clinical and laboratory findings' associations to propose diagnostic indexes and clarified differences based on age distribution.Celiac Disease (CD) and IPH diagnosis was made concurrently in 46 patients, whereas in 21 patients the diagnosis of LHS was delayed for 2.5y (3mo-11y). Hemoptysis (n=56, 70%), dyspnea (n=47, 58.8%), anemia (n=72, 90%) and iron deficiency (n=54, 67.5%) were most commonly observed. Medical history revealed recurrent episodes of hemoptysis (n=38) and persistent iron deficiency anemia (n=25) in need of multiple blood transfusions or iron supplementation. Patchy infiltrate opacities to consolidation predominated in children, whereas bilateral diffuse ground glass opacities in adults. Duodenal biopsy was performed in 66 cases (diagnostic 87.8%), BAL in 51 (diagnostic 74.5%) and surgical lung biopsy in 20. Anti-tTG titer was positive in all 24 (54.6%) children and 19 (52.8%) adults that documented this assay. Prednisone or methylprednisolone pulse therapy and GFD were initiated in the acute phase, whereas chronic therapy included GFD, along with long-term prednisone in refractory cases. Three cases with severe respiratory failure or hemodynamic instability were intubated and a further 3 succumbed.A thorough understanding of LHS may reveal further diagnostic indexes and a consensus on therapy guidelines. Screening for CD is essential in all IPH cases for timely recognition and favorable outcome.

Respiratory Distress: Three Patient Cases

As mentioned in the January 2022 Pediatrics in Review Commentary, we now present three patients who have a common chief complaint followed by 5 questions for CME credit. All three cases have discussions on presentation, the differential diagnosis, and management that collectively serve as a Review article. The common theme here is that all three patients have difficulty breathing. We hope you will enjoy this review format.

Diffuse Alveolar Hemorrhage (DAH) in the Immediate Post-Transplant Setting: An Unusual Case and a Review of Literature

Diffuse alveolar hemorrhage is known to be a devastating clinical condition with myriad etiologies. The immediate post-transplant period is plagued by immunosuppression, surgical complications, and nosocomial sources of infection. Diffuse alveolar hemorrhage in this setting is usually attributed to infection. In this case report, an unusual cause of diffuse alveolar hemorrhage due to anti-thymocyte globulin used as an induction agent is described, and an approach to DAH in the immediate post-transplant setting is discussed.

Hemosiderin-Laden Macrophages in Bronchoalveolar Lavage: Predictive Role for Acute Exacerbation of Idiopathic Interstitial Pneumonias

Background

Hemosiderin-laden macrophages (HLMs) have been identified in the bronchoalveolar lavage fluid (BALF) of patients with idiopathic pulmonary fibrosis (IPF). This retrospective study examined the ability of HLMs in BALF to predict the acute exacerbation (AE) of chronic idiopathic interstitial pneumonias (IIPs).

Methods

Two hundred and twenty-one patients with IIP diagnosed by bronchoscopy were enrolled in the study (IPF, n = 87; IIPs other than IPF, n = 134). Giemsa stain was used to detect HLMs in BALF specimens. Prussian blue stain was used to quantify HLMs in BALF, and a hemosiderin score (HS) was given to the specimens containing HLMs.

Results

Twenty-four patients had a positive HS (range: 7‒132). The receiver-operating characteristic curve analysis identified the cutoff HS value for predicting the AE of IIPs to be 61.5. Seven cases had a higher HS (≥61.5) and 214 had a lower HS. AE occurred significantly earlier in the higher HS group (4/7 cases) than in the lower HS group (41/214 cases) during a median observation period of 1239 days (log-rank test, p = 0.026). Multivariate Cox proportional hazard regression analysis showed that a higher HS was a significant predictor of AE in addition to IPF, percent predicted forced vital capacity, and modified Medical Research Council score. The C-statistics for the prediction of AE did not significantly improve by all the above parameters with HS as compared without HS.

Conclusions

A higher HS was a significant predictor of AE in IIPs but did not significantly improve the predictive ability of other parameters.

Diffuse Alveolar Hemorrhage in Primary Versus Secondary Antiphospholipid Syndrome

BACKGROUND

Diffuse alveolar hemorrhage (DAH) occurs in patients with both primary and secondary antiphospholipid antibody syndrome (APS). We sought to determine the differences in clinical presentation, management, and outcomes of DAH in these patients.

METHODS

We performed a medical records review study and reviewed 30 patients with DAH in the setting of primary and secondary antiphospholipid syndrome seen at our institution between January 1, 1997, and December 31, 2018. We analyzed their demographics, clinical presentation, laboratory values, imaging studies, lung pathology results, management, and outcomes.

RESULTS

The patients in the secondary APS cohort were younger (median age, 48.5 vs 58 years) and comprised more females (75% vs 17%) compared with those with primary APS (p < 0.05). Two thirds of patients in the secondary APS group were anemic compared with less than one fourth in the primary APS group (p = 0.005). At the time of the first episode of DAH, the patients in the secondary APS required invasive and noninvasive ventilation, antibiotics, and combination immunosuppressive therapy (includes a combination of glucocorticoids with immunosuppressants or intravenous immunoglobulins or plasma exchange) more often compared with those with primary APS. There was only one in-hospital death (3% in-hospital mortality). One-year and 5-year mortality rates were 20% and 27%, respectively, with no significant difference between the primary and secondary APS groups.

CONCLUSIONS

Diffuse alveolar hemorrhage in the setting of APS, especially secondary APS, can be severe. However, in-hospital mortality is uncommon with current management strategies.

Anticoagulant Use as an Independent Risk Factor and Higher In-Hospital Mortality in Patients Showing Alveolar Hemorrhage in Diffuse Lung Disease

Background and objectives: Bronchoalveolar lavage (BAL) is commonly performed to evaluate diffuse lung disease and occasionally to identify alveolar hemorrhage. However, the clinical impact of alveolar hemorrhage and its risk factors in patients with diffuse lung disease have not been clarified. Materials and Methods: We retrospectively analyzed the medical records of all patients who underwent BAL to evaluate diffuse lung disease from January 2017 to December 2020. Alveolar hemorrhage was defined as progressive hemorrhagic BAL fluid or the presence of ≥20% hemosiderin-laden macrophages in the BAL fluid. Logistic regression analysis was performed to assess the association between alveolar hemorrhage and other factors. Results: Sixty subjects were enrolled in this study. Alveolar hemorrhage was observed in 19 subjects (31.7%) with idiopathic interstitial pneumonia, acute respiratory distress syndrome, interstitial pneumonia with autoimmune features, drug-induced lung injury, eosinophilic pneumonia, adenocarcinoma, and systemic lupus erythematosus. The use of anticoagulants was a significant risk factor for alveolar hemorrhage (odds ratio 7.57, p = 0.049). Patients with alveolar hemorrhage required intubated mechanical ventilation more frequently (63.2% vs. 24.4%, p = 0.005) and had higher in-hospital mortality rates (26.3% vs. 4.9%, p = 0.028) than those without alveolar hemorrhage. Conclusions: Alveolar hemorrhage was observed in various etiologies. The use of anticoagulants was a significant risk factor for alveolar hemorrhage. Patients with alveolar hemorrhage showed more severe respiratory failure and had higher in-hospital mortality than those without alveolar hemorrhage.

Treatment of Diffuse Alveolar Hemorrhage: Controlling Inflammation and Obtaining Rapid and Effective Hemostasis

Diffuse alveolar hemorrhage (DAH) is a life-threatening pulmonary complication in patients with hematologic malignancies or systemic autoimmune disorders. Pathologic findings show pulmonary capillaritis, bland hemorrhage, diffuse alveolar damage, and hemosiderin-laden macrophages, but in the majority of cases, pathogenesis remains unclear. Despite the severity and high mortality, the current treatment options for DAH remain empirical. Systemic treatment to control inflammatory activity including high-dose corticosteroids, cyclophosphamide, and rituximab and supportive care have been applied, but largely unsuccessful in critical cases. Activated recombinant factor VII (FVIIa) can achieve rapid local hemostasis and has been administered either systemically or intrapulmonary for the treatment of DAH. However, there is no randomized controlled study to evaluate the efficacy and safety, and the use of FVIIa for DAH remains open to debate. This review discusses the pathogenesis, diverse etiologies causing DAH, diagnosis, and treatments focusing on hemostasis using FVIIa. In addition, the risks and benefits of the off-label use of FVIIa in pediatric patients will be discussed in detail.

Bronchoalveolar lavage: role in the evaluation of pulmonary interstitial disease

INTRODUCTION

Bronchoalveolar lavage (BAL), a noninvasive, well-tolerated procedure is an important diagnostic tool that can facilitate the diagnosis of various lung diseases. This procedure allows the assessment of large alveolar compartments, by providing cells as well as non-cellular constituents from the lower respiratory tract. Alterations in BAL fluid and cells ratio reflects pathological changes in the lung parenchyma. In some cases, clinicians use BAL as a differential diagnosis guide for interstitial lung disease.

AREAS COVERED

In this review, we summarized the diagnostic criteria for BAL in interstitial lung diseases, pulmonary infections, lung cancer and other pathologies such as fat embolism, gastroesophageal reflux and collagen vascular disease. For this review, we have selected scientific papers published in the PubMed database in our area of interest. We aimed to highlight the usefulness of BAL in respiratory pathology.

EXPERT OPINION

Although BAL fluid analyzes has an essential role in the diagnostic work-up of many lung pathologies, it should be performed in selected patients. For accurate results, the BAL technique is very important to be standardized.

Deep Learning-Based Quantification of Pulmonary Hemosiderophages in Cytology Slides

Exercise-induced pulmonary hemorrhage (EIPH) is a common condition in sport horses with negative impact on performance. Cytology of bronchoalveolar lavage fluid by use of a scoring system is considered the most sensitive diagnostic method. Macrophages are classified depending on the degree of cytoplasmic hemosiderin content. The current gold standard is manual grading, which is however monotonous and time-consuming. We evaluated state-of-the-art deep learning-based methods for single cell macrophage classification and compared them against the performance of nine cytology experts and evaluated inter- and intra-observer variability. Additionally, we evaluated object detection methods on a novel data set of 17 completely annotated cytology whole slide images (WSI) containing 78,047 hemosiderophages. Our deep learning-based approach reached a concordance of 0.85, partially exceeding human expert concordance (0.68 to 0.86, mean of 0.73, SD of 0.04). Intra-observer variability was high (0.68 to 0.88) and inter-observer concordance was moderate (Fleiss' kappa = 0.67). Our object detection approach has a mean average precision of 0.66 over the five classes from the whole slide gigapixel image and a computation time of below two minutes. To mitigate the high inter- and intra-rater variability, we propose our automated object detection pipeline, enabling accurate, reproducible and quick EIPH scoring in WSI.

Update on the Management of Respiratory Manifestations of the Antineutrophil Cytoplasmic Antibodies-Associated Vasculitides

Antibody-associated vasculitis comprises 3 small vessel vasculitis syndromes: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic polyangiitis (EGPA). This article outlines the major tracheobronchial and pulmonary parenchymal disease manifestations of GPA and MPA and their management, as well as relevant recent advances in the treatment of EGPA. Shared trends in the management of all 3 syndromes are: (1) a focus on glucocorticoid avoidance and (2) an increasing reliance on biologic agents. Evidence from randomized controlled trials and large cohort studies in support of these trends as well as ongoing research efforts are summarized.

Systemic lupus erythematosus and diffuse alveolar hemorrhage, etiology and novel treatment strategies

Diffuse alveolar hemorrhage is a severe respiratory complication of systemic lupus erythematosus. The illness develops over hours to a few days and is the systemic lupus erythematosus-associated syndrome with highest mortality. Although no specific symptoms have been identified, a number of features are associated with diffuse alveolar hemorrhage, with a drop in blood hemoglobin the most prominent. Dyspnea, blood-stained sputum, diffuse infiltrates identified by chest imaging, elevated single breath-diffusing capacity for monoxide, thrombocytopenia and C3 hypocomplementemia are other commonly reported signs of diffuse alveolar hemorrhage. The etiology is not completely understood but many patients develop diffuse alveolar hemorrhage concomitant with lupus nephritis, suggesting immune complex-driven pathology. Biopsy studies have identified both cases with capillaritis and a bland non-inflammatory phenotype. An animal model of diffuse alveolar hemorrhage has indicated requirement of B lymphocytes and complement receptor-mediated apoptotic body phagocytosis by monocytes as part of the pathogenesis. This review will discuss considerations when diagnosing the condition and available therapies. Infections and other causes of hemorrhage have to be excluded as these require different treatment strategies. Methylprednisolone and cyclophosphamide remain the most commonly used therapies. Plasmapheresis and rituximab are other beneficial treatment options. A few studies have also considered intrapulmonary Factor VII therapy, extracorporeal membrane oxygenation and mesenchymal stem cell therapy. There is an unmet need of better definition of diffuse alveolar hemorrhages etiology and pathology for development of improved treatment strategies.

Pathological and Radiological Correlation in Prolonged Myeloperoxidase Anti-neutrophil Cytoplasmic Antibody-related Diffuse Alveolar Hemosiderosis

A 60-year-old woman with a 20-year history of myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis visited our hospital due to productive cough and a low-grade fever for several weeks. Thoracic computed tomography demonstrated scattered tiny nodules, patchy consolidation, ground glass opacities, and thickening interlobular septa. On video-assisted thoracic surgery, those abnormalities were found to correspond to the accumulation of hemosiderin-laden alveolar macrophages (AMs) in the alveolar spaces and alveolar septa due to MPO-ANCA vasculitis. The radiological findings persisted for a further two years, indicating the possibility of persistent vasculitis in the lung or evidence of incomplete clearance of hemosiderin-laden AMs.

Diffuse alveolar hemorrhage: how relevant is etiology?

Background

Diffuse Alveolar Hemorrhage (DAH) is a rare and potentially life-threatening clinical syndrome whose early recognition is essential.

Objectives

Characterization of patients with DAH and comparison of presentation and evolution of the disease according to etiology.

Methods

We retrospectively reviewed the clinical records of patients admitted to our hospital over a 7-year period with DAH. Criteria for DAH (1+2): 1 - hemoptysis and/or pulmonary infiltrates and/or anemia (DAH triad); 2 - hemorrhagic bronchoalveolar lavage (BAL) or siderophagic alveolitis. DAH was grouped in immune and nonimmune and the course of disease was compared.

Results

We included 24 patients admitted with DAH, of which 11 had an immune cause: p-ANCA vasculitis (n=7), Systemic Lupus Erythematosus (n=2), c-ANCA vasculitis (n=1), Rheumatoid Arthritis (n=1) and 13 had a nonimmune cause: heart disease (n=6), amiodarone toxicity (n=2), clotting disorder (n=2), cannabis toxicity (n=1), S. aureus infection (n=1) and idiopathic (n=1). Patients with nonimmune DAH were significantly older than those with immune DAH (67.9±18.1 vs 56.6±18.8 years, p=0.042). DAH triad was observed in 54% of all patients, hemoptysis in 67%, anemia in 79%, and pulmonary infiltrates in all cases. Patients with immune DAH had more frequently pulmonary-renal syndrome (p<0.001), kidney failure (p=0.048), shock (p=0.049) and needed more frequently admition in ICU (p=0.039) and blood transfusion (p=0.043). Hospital length of stay was superior in immune group (29.5±20.0 vs 19.5±14.3 days, p=0.047). In-hospital mortality was exclusive to immune DAH (12.5%).

Conclusions

Patients with DAH due to immune causes were significantly younger, had more severe presentations of the disease and worst outcomes.

The contribution of bronchoalveolar lavage in the diagnosis of welder's lung in a patient with pulmonary fibrosis

Interstitial pulmonary fibrosis is rare clinical entity related to welding usually associated with long term and heavy exposure to welding fumes. A 56-year-old asymptomatic male patient was referred to our clinic due to abnormal chest X-ray findings that was requested for regular controls. He has been working as a welder both indoor and outdoor settings for the last 25 years. The radiological findings were compatible with usual interstitial pneumonia on computed tomography of thorax. Pulmonary function tests, exercise capacity and laboratory results were within normal limits. Collagen tissue markers were negative. In order to confirm the relation of welding with pulmonary fibrosis, bronchoalveolar lavage was performed and stained with Prussian blue. The demonstration of hemosiderin-laden macrophages (25%) confirmed this association and allowed differential diagnosis. Besides it helped the patient decide to leave his job.

Ferritin H Deficiency in Myeloid Compartments Dysregulates Host Energy Metabolism and Increases Susceptibility to Mycobacterium tuberculosis Infection

Iron is an essential factor for the growth and virulence of Mycobacterium tuberculosis (Mtb). However, little is known about the mechanisms by which the host controls iron availability during infection. Since ferritin heavy chain (FtH) is a major intracellular source of reserve iron in the host, we hypothesized that the lack of FtH would cause dysregulated iron homeostasis to exacerbate TB disease. Therefore, we used knockout mice lacking FtH in myeloid-derived cell populations to study Mtb disease progression. We found that FtH plays a critical role in protecting mice against Mtb, as evidenced by increased organ burden, extrapulmonary dissemination, and decreased survival in Fth-/- mice. Flow cytometry analysis showed that reduced levels of FtH contribute to an excessive inflammatory response to exacerbate disease. Extracellular flux analysis showed that FtH is essential for maintaining bioenergetic homeostasis through oxidative phosphorylation. In support of these findings, RNAseq and mass spectrometry analyses demonstrated an essential role for FtH in mitochondrial function and maintenance of central intermediary metabolism in vivo. Further, we show that FtH deficiency leads to iron dysregulation through the hepcidin-ferroportin axis during infection. To assess the clinical significance of our animal studies, we performed a clinicopathological analysis of iron distribution within human TB lung tissue and showed that Mtb severely disrupts iron homeostasis in distinct microanatomic locations of the human lung. We identified hemorrhage as a major source of metabolically inert iron deposition. Importantly, we observed increased iron levels in human TB lung tissue compared to healthy tissue. Overall, these findings advance our understanding of the link between iron-dependent energy metabolism and immunity and provide new insight into iron distribution within the spectrum of human pulmonary TB. These metabolic mechanisms could serve as the foundation for novel host-directed strategies.

Clinical characteristics and prognosis of drug-associated acute respiratory distress syndrome compared with non-drug-associated acute respiratory distress syndrome: a single-centre retrospective study in Japan

OBJECTIVES

To report the clinical features and prognosis of drug-associatedacute respiratory distress syndrome (ARDS).

DESIGN

A retrospective analysis of data collected during a prospective cohort study.

SETTING

Intensive care unit in a teaching hospital.

PARTICIPANTS

A total of 197 Japanese patients with ARDS diagnosed by the Berlin definition who were admitted to the Division of Respiratory Medicine from October 2004 to December 2015 were enrolled in the study and were classified as two groups according to their causes: a drug-associated ARDS group (n=27) and a non-drug-associated ARDS group (n=170). Primary outcome measure is 28-day mortality, and the secondaryoutcome measure is ventilator-free days.

RESULTS

The Acute Physiology and Chronic Health Evaluation II scores were significantly lower in the drug-associated ARDS group than in the non-drug-associated ARDS group (median (IQR): 18.0 (16.5-21.0) vs 23.0 (18.0-26.0), p<0.001), and the arterial oxygen tension/fractional inspired oxygen ratio was higher (148.0 (114.1-177.5) vs 101.0 (71.5-134.0), p=0.003). In the drug-associated ARDS group, although high-resolution CT scores indicative of the extent of fibroproliferation (301.6 (244.1-339.8) vs 208.3 (183.4-271.6), p<0.001), serum lactate dehydrogenase levels (477 (365-585) vs 322 (246-434), p=0.003) and the McCabe scores (score 1/2/3, n (%): 20 (74)/4 (15)/3 (11)vs154 (91)/7 (4)/9 (5), p=0.04) were significantly higher, ventilator weaning was earlier (p<0.001) and 28-day mortality was better (p=0.043). After adjusting for potentially confounding covariates, drug-associated ARDS group was associated with lower 28-day mortality (adjusted HR (HR) 0.275; 95% CI 0.106 to 0.711; p=0.008).

CONCLUSIONS

Although more severe lung damage with fibroproliferation was observed in patients with drug-associated ARDS, ventilator weaning was earlier, and their prognosis was better than the others. Further well-designed prospective studies are needed.

Sequential adjuvant chemoradiotherapy-induced diffuse alveolar haemorrhage in a patient with breast cancer successfully treated with corticosteroid plus recombinant human soluble thrombomodulin

The effective treatment for corticosteroid (CS)-refractory sequential chemoradiotherapy (CRT)-induced lung injury has not been established. We report a case of sequential CRT-induced diffuse alveolar haemorrhage (DAH) successfully treated with CS therapy plus recombinant human soluble thrombomodulin (rhTM). A 69-year-old woman was treated with sequential adjuvant CRT for early-stage breast cancer. After sequential CRT, she suffered from progressive dyspnoea. Chest CT scan showed consolidations in the irradiation field and diffuse ground-glass attenuations in the non-irradiation regions. We suspected sequential CRT-induced DAH because of increased haemosiderin-laden macrophages in bronchoalveolar lavage fluid. Her clinical conditions did not improve with high-dose CS therapy. Therefore, rhTM was added, and her disease and serum high-mobility group box-1 levels improved rapidly. Therefore, rhTM plus CS might be a safe and effective treatment for sequential CRT-induced lung injury, although further study is necessary to validate these findings.

HFE gene variants and iron-induced oxygen radical generation in idiopathic pulmonary fibrosis

In idiopathic pulmonary fibrosis (IPF), lung accumulation of excessive extracellular iron and macrophage haemosiderin may suggest disordered iron homeostasis leading to recurring microscopic injury and fibrosing damage. The current study population comprised 89 consistent IPF patients and 107 controls. 54 patients and 11 controls underwent bronchoalveolar lavage (BAL). Haemosiderin was assessed by Perls' stain, BAL fluid malondialdehyde (MDA) by high-performance liquid chromatography, BAL cell iron-dependent oxygen radical generation by fluorimetry and the frequency of hereditary haemochromatosis HFE gene variants by reverse dot blot hybridisation. Macrophage haemosiderin, BAL fluid MDA and BAL cell unstimulated iron-dependent oxygen radical generation were all significantly increased above controls (p<0.05). The frequency of C282Y, S65C and H63D HFE allelic variants was markedly higher in IPF compared with controls (40.4% versus 22.4%, OR 2.35, p=0.008) and was associated with higher iron-dependent oxygen radical generation (HFE variant 107.4±56.0, HFE wild type (wt) 59.4±36.4 and controls 16.7±11.8 fluorescence units per 10(5) BAL cells; p=0.028 HFE variant versus HFE wt, p=0.006 HFE wt versus controls). The data suggest iron dysregulation associated with HFE allelic variants may play an important role in increasing susceptibility to environmental exposures, leading to recurring injury and fibrosis in IPF.

Serum ferritin is an important inflammatory disease marker, as it is mainly a leakage product from damaged cells

"Serum ferritin" presents a paradox, as the iron storage protein ferritin is not synthesised in serum yet is to be found there. Serum ferritin is also a well known inflammatory marker, but it is unclear whether serum ferritin reflects or causes inflammation, or whether it is involved in an inflammatory cycle. We argue here that serum ferritin arises from damaged cells, and is thus a marker of cellular damage. The protein in serum ferritin is considered benign, but it has lost (i.e. dumped) most of its normal complement of iron which when unliganded is highly toxic. The facts that serum ferritin levels can correlate with both disease and with body iron stores are thus expected on simple chemical kinetic grounds. Serum ferritin levels also correlate with other phenotypic readouts such as erythrocyte morphology. Overall, this systems approach serves to explain a number of apparent paradoxes of serum ferritin, including (i) why it correlates with biomarkers of cell damage, (ii) why it correlates with biomarkers of hydroxyl radical formation (and oxidative stress) and (iii) therefore why it correlates with the presence and/or severity of numerous diseases. This leads to suggestions for how one might exploit the corollaries of the recognition that serum ferritin levels mainly represent a consequence of cell stress and damage.

Stress Cardiomyopathy Associated with Diffuse Alveolar Hemorrhage after Colonoscopy

Stress cardiomyopathy (SCM) is usually precipitated by a physiologically or psychologically stressful event. Although it occurs only rarely, hypoxia- and hypercapnia-induced sympathetic activation may also cause SCM. We present the case of a 37-year-old woman affected with SCM after a routine colonoscopy. During the procedure, she aspirated residual polyethylene glycol from her stomach. Hypotension, resting dyspnea, and hemoptysis were subsequently observed. Laboratory findings revealed elevated cardiac enzymes, and a transthoracic echocardiogram revealed left ventricular (LV) global hypokinesia. She was ultimately diagnosed with diffuse alveolar hemorrhage-associated SCM. After successful treatment with a ventilator and corticosteroids, her LV systolic function and dimensions normalized and she was discharged without complications.

Diffuse alveolar hemorrhage in coumarin users: a fibrosing interstitial pneumonia trigger?

BACKGROUND

Fibrosing interstitial pneumonias (IPs) include idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP). It has been suggested that oxidative damage plays a role in the pathophysiology of idiopathic interstitial pneumonias. Diffuse alveolar hemorrhage (DAH) can cause oxidative stress. Accordingly, we hypothesized that episodes of DAH might trigger fibrosing IP development.

METHODS

Patients using coumarins with confirmed DAH were retrospectively gathered during a 9 year period and reviewed for the development of IPF or fibrosing NSIP.

RESULTS

A total of 65 patients with DAH could finally be included, 31 (48 %) of whom subsequently developed a fibrosing IP. The majority of these 31 patients developed the fibrosing IP within 3 years after DAH confirmation. A total of 41 (63 %) patients died within 3.0 ± 0.9 (range 1.3-4.7) years after the DAH diagnosis had been confirmed. Twenty-two of the deceased (54 %) had finally developed fibrosing IP.

CONCLUSIONS

Almost half of the patients with established episodes of DAH developed fibrosing IP; therefore it seems that DAH might be a trigger for the development of fibrosing IP. This observation warrants prospective studies to further evaluate the clinical impact of these findings.

[Acute respiratory distress syndrome related to intra-alveolar hemorrhage revealing a vasculitis]

Intra-alveolar hemorrhage (IAH) could be revealed by acute respiratory failure. The classic association of hemoptysis - anemia - radiological infiltrates is suggestive and has to be confirmed by broncho-alveolar lavage with Golde score. Etiologies included immune and non-immune diseases, with specific treatment for each. We report a case of IAH revealed by acute respiratory distress syndrome and anemia (3 g/dL), related to pulmonary and cerebral vasculitis without renal involvement. The patient was efficiently treated with corticosteroids and cyclophosphamide. This case highlights the critical role of BAL cytological analysis with Golde score, and the need for a rapid and accurate diagnosis in order to guide specific treatment. If histology is needed, renal biopsy even without renal involvement, or surgical lung biopsy is possible.

Update on diffuse alveolar hemorrhage and pulmonary vasculitis

Diffuse alveolar hemorrhage is a clinical syndrome that can be a manifestation of multiple different causes. Identification of the underlying etiology is of utmost importance and dictates treatment. Pulmonary vasculitis including antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a common cause of diffuse alveolar hemorrhage. For AAV, treatment includes induction followed by maintenance therapy. Rituximab has an increasing role in the treatment of AAV.

IL-10R blockade during chronic schistosomiasis mansoni results in the loss of B cells from the liver and the development of severe pulmonary disease

In schistosomiasis patients, parasite eggs trapped in hepatic sinusoids become foci for CD4+ T cell-orchestrated granulomatous cellular infiltrates. Since the immune response is unable to clear the infection, the liver is subjected to ongoing cycles of focal inflammation and healing that lead to vascular obstruction and tissue fibrosis. This is mitigated by regulatory mechanisms that develop over time and which minimize the inflammatory response to newly deposited eggs. Exploring changes in the hepatic inflammatory infiltrate over time in infected mice, we found an accumulation of schistosome egg antigen-specific IgG1-secreting plasma cells during chronic infection. This population was significantly diminished by blockade of the receptor for IL-10, a cytokine implicated in plasma cell development. Strikingly, IL-10R blockade precipitated the development of portal hypertension and the accumulation of parasite eggs in the lungs and heart. This did not reflect more aggressive Th2 cell responsiveness, increased hepatic fibrosis, or the emergence of Th1 or Th17 responses. Rather, a role for antibody in the prevention of severe disease was suggested by the finding that pulmonary involvement was also apparent in mice unable to secrete class switched antibody. A major effect of anti-IL-10R treatment was the loss of a myeloid population that stained positively for surface IgG1, and which exhibited characteristics of regulatory/anti-inflammatory macrophages. This finding suggests that antibody may promote protective effects within the liver through local interactions with macrophages. In summary, our data describe a role for IL-10-dependent B cell responses in the regulation of tissue damage during a chronic helminth infection.

Pulmonary vasculitis in the intensive care unit

Pulmonary vasculitis can occur in apparent isolation, as part of a primary systemic vasculitis, or with an underlying systemic inflammatory autoimmune disorder. The presentation of pulmonary vasculitis in the intensive care unit (ICU) can be fulminant and will often overlap with more common disorders that affect the critically ill. Although diffuse alveolar hemorrhage (DAH) is the clinical feature that often initiates the concern for an underlying vasculitis, hemoptysis may not be apparent or its presentation can be mistaken for an alternative disease process. As a result, the diagnosis of pulmonary vasculitis in the ICU may be delayed or be completely unrecognized. A high level of suspicion is essential to obtain a timely diagnosis and for effective therapies to be implemented. There have been significant advances this past decade in diagnostic strategies as well as in the therapeutic options for patients with pulmonary vasculitis. We review here the clinical presentations, diagnostic strategies, and treatment options of the critically ill patients presenting with pulmonary vasculitis. The reader is referred to other resources for a more comprehensive review of specific vasculitic entities.

[Journal of the year 2009 in interventionist pneumology, interstitial diseases and transplant]

Endobronchial ultrasound bronchoscopy has been one of the most important contributions to the minimally invasive diagnosis and staging of mediastinal disease in the last few years. Two original works with linear and radial endobronchial ultrasound bronchoscopy published in the Archivos de Bronconeumología are analysed. In pleural pathology, we have selected a multicentre study one the usefulness of an outpatient tunnelised pleural drainage in 63 patients with malignant neoplastic effusions. This technique was indicated in 20% when pleurodesis failed or was not indicated, and an overall symptomatic improvement was achieved in 95% of cases. In interstitial diseases, we highlight the article on the usefulness of BAL in the initial diagnosis of these diseases in a series of 562 patients studied over 14 years. The authors highlight the minimal invasiveness of the technique and its value which, when added to the radiological and clinical findings, enables these diseases to be managed without surgical biopsy in around 90% of cases. Finally, we highlight the works on lung transplant which analysed the value of interleukin-8 by BAL in the donor lung to detect sub-clinical involvement that could lead to a primary dysfunction of the lung graft, the risk factors associated to mortality in 92 lung transplant receivers due to emphysema and, lastly, the experience of the transplant in 15 patients with pulmonary arterial hypertension in an advanced functional class, with a peri-operative survival at 5 years of 40%.