Eosinophilic Lung Disease

Εosinophilic Chronic Obstructive Pulmonary Disease. What Do We Know So Far?

The latest advances in asthma treatment have highlighted the significance of eosinophilia and the possible role of some pro-eosinophilic mediators, like interleukins (IL) IL-5, IL-4/IL-13, and IL-33 in the disease's pathogenesis. Considering that a subgroup of patients with chronic obstructive pulmonary disease (COPD) may have blood eosinophilia akin to that seen in asthma, numerous studies in the last decade have suggested that eosinophilic COPD is a separate entity. While the exact role of blood eosinophils in the pathophysiology of COPD remains unclear, eosinophilia seems to increase the effectiveness of corticosteroid therapy. Currently, monoclonal antibodies targeting the interleukins (IL-5, IL-4, IL-13, and IL-33) or their receptors are being investigated in patients with COPD belonging in T2-high endotype. This review focuses on the mechanisms of eosinophilia in COPD, the effects of eosinophilia on disease outcome, and examines the most recent data on the use of peripheral blood eosinophilia in treating patients with COPD. Finally, we emphasize the current implication of monoclonal antibodies in COPD in the context of eosinophilic airway inflammation.

Review of Peripheral Blood Eosinophilia: Workup and Differential Diagnosis

Eosinophils are a type of granulocyte key to immune system modulation seen in a number of disease processes. Nearly every major organ system can be connected to peripheral eosinophilia through a number of different disease processes, ranging from benign conditions to malignancy. In this paper, we review both common and rare causes of peripheral eosinophilia, their symptoms, and a framework for the workup of peripheral eosinophilia of unknown etiology.

[Eosinophilic chronic obstructive pulmonary disease: A review]

Over the past decades, chronic obstructive pulmonary disease (COPD) has become a major public health problem due to increasing morbidity and mortality. COPD is characterized by airflow limitation due to inflammation of the bronchial tree and remodeling of the small airways. In 20-40% of patients with COPD, eosinophilic inflammation of the airways is observed, as in bronchial asthma. Eosinophilic COPD has recently been shown to be a distinct disease and is associated with more pronounced airway remodeling. Although the role of eosinophils in the pathogenesis of COPD is not fully understood, the level of eosinophils can be used in the prognosis and administration of corticosteroids, and their effectiveness is higher in eosinophilia. Currently, monoclonal antibodies directed against interleukins (IL-5, IL-4 and IL-13) or their receptors are being tested in the T2 endotype of COPD. This review focuses on the mechanisms of eosinophilia in COPD, the use of blood and sputum eosinophils as a biomarker, and the advisability of using monoclonal antibodies in the treatment of eosinophilic COPD.

A case of chronic eosinophilic pneumonia associated with rheumatoid arthritis in glucocorticoid-free remission with JAK inhibitor: A case report

RATIONALE

Chronic eosinophilic pneumonia (CEP) presents eosinophil infiltrations in the lung due to allergic reactions. Most CEP patients continue to take glucocorticoids, and their prolonged use induces various side effects. In this case report, based on the efficacy of baricitinib in patients with rheumatoid arthritis (RA) and CEP, we aimed to show that the administration of Janus kinase (JAK) inhibitors, when RA is complicated by an allergic disease, can stabilize the disease state and help avoid the adverse effects of long-term systemic glucocorticoid administration.

PATIENTS CONCERNS

A 56-year-old woman developed RA at the age of 19 years. Treatment of the arthritis was initiated, but the joint destruction had progressed. At the age of 42, she developed eosinophilic pneumonia, which was relieved by glucocorticoid therapy. Since then, maintenance therapy has been continued with the diagnosis of CEP. She was treated with concomitant tacrolimus for persistent arthritis, and the prednisolone (PSL) dose was reduced to 3 mg/day after 10 years. However, around this time, an increase in peripheral blood eosinophil counts and respiratory symptoms was observed.

DIAGNOSIS

The peripheral blood eosinophil count was 4000/µL and computed tomography revealed multiple ground-glass opacities in the peripheral lung fields. As interstitial pneumonia due to infection or other causes was ruled out, CEP relapse was diagnosed.

INTERVENTIONS

Pneumonia rapidly recovered when the PSL dose was increased to 15 mg/day, and asymptomatic eosinophilic infiltrates reappeared in the lung field along with a relapse of arthritis when the PSL dose was reduced to 5 mg/day. Concomitant use of methotrexate and baricitinib has been introduced to suppress allergic reactions to pneumonia.

OUTCOMES

After starting combination therapy with baricitinib and methotrexate, both arthritis and eosinophilia improved, and glucocorticoid-free remission was achieved.

LESSONS

Recently, inhibition of IL-5 signaling via JAK2 has been reported to be effective in bronchial asthma and atopic dermatitis. Although complications of RA and CEP are not common, the actions of baricitinib are useful not only in arthritis but also in allergic diseases. The efficacy of some JAK inhibitors should be actively tested in patients with RA and these complications.

Sophoraflavanone G from Sophora flavescens Ameliorates Allergic Airway Inflammation by Suppressing Th2 Response and Oxidative Stress in a Murine Asthma Model

Sophoraflavanone G (SG), isolated from Sophora flavescens, has anti-inflammatory and anti-tumor bioactive properties. We previously showed that SG promotes apoptosis in human breast cancer cells and leukemia cells and reduces the inflammatory response in lipopolysaccharide-stimulated macrophages. We investigated whether SG attenuates airway hyper-responsiveness (AHR) and airway inflammation in asthmatic mice. We also assessed its effects on the anti-inflammatory response in human tracheal epithelial cells. Female BALB/c mice were sensitized with ovalbumin, and asthmatic mice were treated with SG by intraperitoneal injection. We also exposed human bronchial epithelial BEAS-2B cells to different concentrations of SG to evaluate its effects on inflammatory cytokine levels. SG treatment significantly reduced AHR, eosinophil infiltration, goblet cell hyperplasia, and airway inflammation in the lungs of asthmatic mice. In the lungs of ovalbumin-sensitized mice, SG significantly promoted superoxide dismutase and glutathione expression and attenuated malondialdehyde levels. SG also suppressed levels of Th2 cytokines and chemokines in lung and bronchoalveolar lavage samples. In addition, we confirmed that SG decreased pro-inflammatory cytokine, chemokine, and eotaxin expression in inflammatory BEAS-2B cells. Taken together, our data demonstrate that SG shows potential as an immunomodulator that can improve asthma symptoms by decreasing airway-inflammation-related oxidative stress.

Fisetin Suppresses the Inflammatory Response and Oxidative Stress in Bronchial Epithelial Cells

Fisetin is isolated from many fruits and vegetables and has been confirmed to improve airway hyperresponsiveness in asthmatic mice. However, whether fisetin reduces inflammatory response and oxidative stress in bronchial epithelial cells is unclear. Here, BEAS-2B human bronchial epithelial cells were treated with various concentrations of fisetin and then stimulated with tumor necrosis factor-α (TNF-α) or TNF-α/interleukin-4. In addition, ovalbumin-sensitized mice were treated with fisetin to detect inflammatory mediators and oxidative stress expression. Fisetin significantly reduced the levels of inflammatory cytokines and chemokines in TNF-α-stimulated BEAS-2B cells. Fisetin also attenuated intercellular adhesion molecule-1 expression in TNF-α-stimulated BEAS-2B cells, suppressing THP-1 monocyte adhesion. Furthermore, fisetin significantly suppressed airway hyperresponsiveness in the lungs and decreased eosinophil numbers in the bronchoalveolar lavage fluid of asthmatic mice. Fisetin decreased cyclooxygenase-2 expression, promoted glutathione levels, and decreased malondialdehyde levels in the lungs of asthmatic mice. Our findings indicate that fisetin is a potential immunomodulator that can improve the pathological features of asthma by decreasing oxidative stress and inflammation.

Excipient lung disease secondary to intravenous heroin use

We present a case of a woman who had progressive shortness of breath and wheezing with a mild restrictive pulmonary function pattern. She was initially diagnosed with eosinophilic granulomatosis with polyangiitis on the basis of peripheral eosinophilia, bronchoalveolar lavage eosinophilia (47%) and surgical lung biopsy findings. Six months following her diagnosis, the patient returned because of persistent symptoms, and a second review of the lung biopsy revealed thrombotic lesions in the pulmonary vessels with polarisable foreign body materials, associated giant cell reactions and numerous eosinophil infiltrates, consistent with intravenous drug abuse. Further investigation showed that she had a history of intravenous heroin overdose, and the diagnosis of excipient lung disease was made. This case highlights the importance of expert pathological, radiological and clinical review of complex presentations and the need for a thorough medication and drug use history review.

Rapidly progressive respiratory failure after helminth larvae ingestion

BACKGROUND

Self-administration of helminths has gained attention among patients as a potential but unproven therapy for autoimmune disease. We present a case of rapidly progressive respiratory failure in a patient with systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH) as a result of self-administration of parasitic organisms.

CASE

A 45-year-old woman with a history of interstitial lung disease and PAH due to limited cutaneous SSc presented to pulmonary clinic with worsening dyspnea, cough, and new onset hypoxemia. Three months prior to presentation she started oral helminth therapy with Necator americanus as an alternative treatment for SSc. Laboratory evaluation revelaed eosinophilia and elevated IgE levels. IgG antibodies to Strongyloides were detected. High resolution computed tomography of the chest revealed progressive ILD and new diffuse ground glass opacities. Transthoracic echocardiogram and right heart catheterization illustrated worsening PAH and right heart failure. The patient was admitted to the hospital and emergently evaluated for lung transplantation but was not a candidate for transplantation due to comorbidities. Despite aggressive treatment for PAH and right heart failure, her respiratory status deteriorated, and the patient transitioned to comfort-focused care.

CONCLUSION

Although ingestion of helminths poses a risk of infection, helminth therapy has been investigated as a potential treatment for autoimmune diseases. In this case, self-prescribed helminth ingestion precipitated fatal acute worsening of lung inflammation, hypoxemia, and right heart dysfunction, highlighting the risk of experimental helminth therapy in patients, especially those with underlying respiratory disease.

Ginsenoside Rg3 ameliorates allergic airway inflammation and oxidative stress in mice

Background

Ginsenoside Rg3, isolated from Panax ginseng, has anti-inflammatory and anti-tumor activities. It is known to reduce inflammation in acute lung injury in mice, and to reduce the expression of inflammatory cytokines and COX-2 in human asthmatic airway epithelium. In this study, we attempted to determine whether ginsenoside Rg3 inhibits airway inflammation, oxidative stress, and airway hyperresponsiveness (AHR) in the lungs of asthmatic mice. We also investigated its effects on oxidative stress and the inflammatory response in tracheal epithelial cells.

Methods

Asthma symptoms were induced in female BALB/c mice sensitized with ovalbumin (OVA). Mice were divided into five groups: normal controls, OVA-induced asthmatic controls, and asthmatic mice treated with ginsenoside Rg3 or prednisolone by intraperitoneal injection. Inflammatory BEAS-2B cells (human tracheal epithelial cells) treated with ginsenoside Rg3 to investigate its effects on inflammatory cytokines and oxidative responses.

Results

Ginsenoside Rg3 treatment significantly reduced eosinophil infiltration, oxidative responses, airway inflammation, and AHR in the lungs of asthmatic mice. Ginsenoside Rg3 reduced Th2 cytokine and chemokine levels in bronchoalveolar lavage fluids and lung. Inflammatory BEAS-2B cells treated with ginsenoside Rg3 reduced the eotaxin and pro-inflammatory cytokine expressions, and monocyte adherence to BEAS-2B cells was significantly reduced as a result of decreased ICAM-1 expression. Furthermore, ginsenoside Rg3 reduced the expression of reactive oxygen species in inflammatory BEAS-2B cells.

Conclusion

Ginsenoside Rg3 is a potential immunomodulator that can ameliorate pathological features of asthma by decreasing oxidative stress and inflammation

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Ginsenoside Rg3 reduced eosinophil infiltration, and airway hyperresponsiveness in the lungs of asthmatic mice.

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Ginsenoside Rg3 inhibited oxidative responses in the lungs.

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Ginsenoside Rg3 reduced the levels of Th2 cytokines in BALF and lung.

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Ginsenoside Rg3 inhibited monocyte cell adherence to tracheal epithelial cells.

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Ginsenoside Rg3 reduced the levels of pro-inflammatory cytokines in tracheal epithelial cells.

Eosinophilic Chronic Obstructive Pulmonary Disease

Recent therapeutic advances in the management of asthma have underscored the importance of eosinophilia and the role of pro-eosinophilic mediators such as IL-5 in asthma. Given that a subset of patients with COPD may display peripheral eosinophilia similar to what is observed in asthma, a number of recent studies have implied that eosinophilic COPD is a distinct entity. This review will seek to contrast the mechanisms of eosinophilia in asthma and COPD, the implications of eosinophilia for disease outcome, and review current data regarding the utility of peripheral blood eosinophilia in the management of COPD patients.

Clinical characteristics of patients with chronic eosinophilic pneumonia in a Chinese tertiary-care hospital: A 6-year retrospective study

Introduction

Chronic eosinophilic pneumonia (CEP) is a rare disease with unknown etiology. Due to lack of specificity of CEP symptoms, clinicians are not experienced in establishing its diagnosis.

Objectives

To summarize the clinical data of CEP patients to improve the understanding of CEP and reduce misdiagnosis.

Methods

Data of patients pathologically diagnosed with CEP in the PLA General Hospital between May 2013 and May 2019 were collected, and clinical manifestations, imaging characteristics, pathological features, and treatment were retrospectively analyzed.

Results

Twenty patients, including 6 males and 14 females, were diagnosed with CEP. The average age was 47.0 ± 10.2 years. The main clinical manifestations were cough and dyspnea. The average duration of CEP was 15.5 ± 11.5 months. The average proportion of eosinophils in the peripheral blood was 18.9 ± 17.8%, and the average proportion of eosinophils in the bronchoalveolar lavage fluid was 41.5 ± 19.4%. The main imaging features were patchy shadows and consolidation shadows. The most common manifestations on bronchoscopic examination were congestion and edema of the bronchial mucosa. Two patients had granular protrusions of the endotracheal membrane. Histological examination indicated infiltration of numerous eosinophils. All patients improved after prednisone therapy.

Conclusion

CEP onset is insidious, and clinical manifestations lack specificity. Typical imaging features are peripheral and subpleural distribution of lung infiltrates. Some patients have a normal proportion of eosinophils in the peripheral blood, but most have an increased number of eosinophils in the BALF, which contributes to CEP diagnosis. A biopsy is necessary when differential diagnosis is difficult. A systemic glucocorticoid is effective.

Therapeutic Effects of an Anti-sialyl Lewis X Antibody in a Murine Model of Allergic Asthma

Asthma is an allergic disease that causes severe infiltration of leukocytes into the lungs. Leukocyte infiltration is mediated by the binding of sialyl Lewis X (sLex) glycans present on the leukocytes to E-and P-selectins present on the endothelial cells at the sites of inflammation. Here, we found that mouse eosinophils express sLex glycans, and their infiltration into the lungs and proliferation in the bone marrow were significantly suppressed by an anti-sLex monoclonal antibody (mAb) F2 in a murine model of ovalbumin-induced asthma. The percentage of eosinophils in the bronchoalveolar lavage fluid and bone marrow and serum IgE levels decreased significantly in the F2-administered mice. Levels of T helper type 2 (Th2) cytokines and chemokines, involved in IgE class switching and eosinophil proliferation and recruitment, were also decreased in the F2-administered mice. An ex vivo cell rolling assay revealed that sLex glycans mediate the rolling of mouse eosinophils on P-selectin-expressing cells. These results indicate that the mAb F2 exerts therapeutic effects in a murine model of allergen-induced asthma, suggesting that sLex carbohydrate antigen could serve as a novel therapeutic target for allergic asthma.

Case Report: Clonorchis sinensis Infection Associated with Eosinophilic Pneumonia: A Case Report and Review of the Literature

Clonorchis sinensis, a trematode prevalent in East Asia, causes hepatobiliary infection. Exposure typically occurs through ingestion of raw or undercooked fish containing the encysted larval form of the parasite. Extrahepatobiliary disease has not commonly been described. In this case report, we describe an unusual case of C. sinensis infection associated with eosinophilic pneumonia. A middle-aged man from China presented with subacute cough and was found to have a bilateral diffuse eosinophilic pneumonia with associated peripheral eosinophilia. Stool microscopy revealed C. sinensis eggs, and the patient improved after treatment with prednisone and praziquantel. Pulmonary clonorchiasis should be considered in patients with eosinophilic pneumonia from areas highly endemic for this pathogen.

May 2020: Is It Always COVID-19 No Matter What?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing a massive outbreak throughout the world. In this period, diseases other than coronavirus disease (COVID-19) have not disappeared; however, it is hard for doctors to diagnose diseases that can mimic the clinical, radiological, and laboratory features of COVID-19, especially rare lung diseases such as acute eosinophilic pneumonia (AEP). We report the clinical case of a young patient who presented to the Emergency Department with respiratory failure and clinical symptoms, radiological aspects, and blood tests compatible with COVID-19; two swabs and a serology test for SARS-CoV-2 were performed, both resulted negative, but the respiratory failure worsened. Peripheral eosinophilia guided us to consider the possibility of a rare disease such as AEP, even if radiology findings were not pathognomonic. Therefore, we decided to perform a flexible bronchoscopy with bronchoalveolar lavage (BAL) at the lingula, which showed the presence of eosinophilia greater than 40%. As a consequence, we treated the patient with high-dose corticosteroids that completely resolved the respiratory symptoms. This case report highlights the difficulty of making alternative diagnoses during the COVID-19 pandemic, especially for rare lung diseases such as AEP, which may have initial characteristics similar to COVID-19.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

Eosinophilic bronchitis, eosinophilic granuloma, and eosinophilic bronchopneumopathy in 75 dogs (2006-2016)

Background

Eosinophilic lung disease is a poorly understood inflammatory airway disease that results in substantial morbidity.

Objective

To describe clinical findings in dogs with eosinophilic lung disease defined on the basis of radiographic, bronchoscopic, and bronchoalveolar lavage fluid (BAL) analysis. Categories included eosinophilic bronchitis (EB), eosinophilic granuloma (EG), and eosinophilic bronchopneumopathy (EBP).

Animals

Seventy‐five client owned dogs.

Methods

Medical records were retrospectively reviewed for dogs with idiopathic BAL fluid eosinophilia. Information abstracted included duration and nature of clinical signs, bronchoscopic findings, and laboratory data. Thoracic radiographs were evaluated for the pattern of infiltrate, bronchiectasis, and lymphadenomegaly.

Results

Thoracic radiographs were normal or demonstrated a bronchial pattern in 31 dogs assigned a diagnosis of EB. Nine dogs had intraluminal mass lesions and were bronchoscopically diagnosed with EG. The remaining 35 dogs were categorized as having EBP based on radiographic changes, yellow green mucus in the airways, mucosal changes, and airway collapse. Age and duration of cough did not differ among groups. Dogs with EB were less likely to have bronchiectasis or peripheral eosinophilia, had lower total nucleated cell count in BAL fluid, and lower percentage of eosinophils in BAL fluid compared to dogs in the other 2 groups. In contrast to previous reports, prolonged survival (>55 months) was documented in dogs with EG.

Conclusions and Clinical Importance

Dogs with eosinophilic lung disease can be categorized based on imaging, bronchoscopic and BAL fluid cytologic findings. Further studies are needed to establish response to treatment in these groups.

A case of chronic eosinophilic pneumonia in a patient treated with dupilumab

The increasing knowledge on inflammatory pathways has driven the development of targeted biological therapies for severe refractory asthma. Among the recently developed biologics, the fully human monoclonal antibody dupilumab is an interesting therapeutic option, given its ability to inhibit the biological effects of both IL-4 and IL-13. We describe the case of a male, Caucasian, 56-year-old patient with allergic and eosinophilic severe asthma. Given the poor asthma control, he started treatment with add-on dupilumab, and after the tenth injection, he presented with a fever and bilateral pulmonary thickening. A significant increase in blood eosinophilia was also reported. The patient underwent a fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB/TBB). BAL revealed eosinophils alveolitis (60%) while TBB showed findings compatible with chronic eosinophilic pneumonia (CEP). After prolonged treatment with oral corticosteroids, the clinical picture improved with resolution of CEP. Since the beginning of dupilumab treatment, simultaneously to a great improvement in asthma control, the patient showed a progressive increase in blood eosinophils count and subsequent onset of clinical-radiological pattern suggestive of CEP. Based on published data, dupilumab may have induced an alteration of the complex immunological pathway of our patient. This pathway is affected by both allergic and eosinophilic asthmatic endotypes, and consequently, the concomitant action of allergenic stimuli and eosinophils may have caused the appearance of eosinophilic pneumonia. To our knowledge, this is the first reported case of CEP as a possible severe side effect of dupilumab administration.

Evaluation of the efficacy of isopathic immunotherapy in the treatment of allergic asthma in BALB/C mice

Introduction: Homeopathy is a therapeutic method based on the fundamental principle of "like cures like." Homeopathic remedies are extremely dilute but involve vigorous shaking at each dilution. Isopathy is one approach of homeopathy, in which the causative agents or products of a disease are used to treat the same disease. Allergen immunotherapy is the only potential disease-modifying treatment for allergic patients. Subcutaneous immunotherapy is more effective than sublingual immunotherapy. However, subcutaneous immunotherapy is ineffective at a low dose, whereas at high doses it can result in an unacceptably high frequency of systemic reactions. In the current study, we evaluated the efficacy of isopathic immunotherapy with highly diluted ovalbumin (HD OVA) in the treatment of OVA-induced allergic asthma in BALB/c mice.Methods: BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received HD OVA on days 21, 22, 32 and 41 (8 h after the last challenge) of the treatment. The mice were challenged with OVA (5%) aerosols on days 35, 38 and 41 for 20 minutes using an ultrasonic nebulizer and sacrificed the next day.Results: Isopathic immunotherapy significantly reduced lung tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and interleukin-4 production. It also insignificantly increased the production of transforming growth factor-beta and proliferation of regulatory T cells against the allergen.Conclusion: Isopathic immunotherapy may be a good candidate treatment for allergic asthma.

Evaluation of the efficacy of nicotine in treatment of allergic asthma in BALB/c mice

Nicotine, an nAChR agonist, shows prominent anti-inflammatory properties, and some studies have illustrated its suppressive effects on inflammation. Here, we have examined whether nicotine as a medicine may have beneficial effects on the treatment of asthma in a mouse model of allergic asthma. BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received nicotine with concentrations of 1 and 10 mg/kg three times every other day. After 10 days, the mice were challenged with OVA (5%) using an ultrasonic nebulizer and died the next day. Our results showed that the administration of nicotine reduced lung-tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and IL-4 production, while it increased the TGF-β/IL-4 ratio and the number of Treg cells. Our results showed that nicotine applies its suppressive effects in a dose-dependent manner: administration of 10 mg/kg of nicotine showed more suppressive effects than 1 mg/kg. Such data suggested that nicotine might be a good candidate to be used as a medicine in the treatment of allergic asthma by decreasing allergic inflammation severity and potentiating Treg cells proliferation against the allergen.