Published papers

The clinical course of coronavirus disease 2019 (COVID-19) varies from mild to critical. We retrospectively examined whether clinical and laboratory findings on admission could predict COVID-19 prognosis. Among various factors associated with COVID-19 severity, our results indicated that the real-time reverse transcription-polymerase chain reaction (RT-PCR) threshold cycle (Ct) values for severe acute respiratory syndrome coronavirus 2 were the most useful predictor of COVID-19 prognosis.

© 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd. Background: Asthma is characterized by airway inflammation and obstruction with eosinophil infiltration into the airway. Arachidonic acid, an omega-6 fatty acid, is metabolized into cysteinyl leukotriene with pro-inflammatory properties for allergic inflammation, whereas the omega-3 fatty acid eicosapentaenoic acid (EPA) and its downstream metabolites are known to have anti-inflammatory effects. In this study, we investigated the mechanism underlying the counter-regulatory roles of EPA in inflamed lungs. Methods: Male C57BL6 mice were sensitized and challenged by ovalbumin (OVA). After EPA treatment, we evaluated the cell count of Bronchoalveolar lavage fluid (BALF), mRNA expressions in the lungs by q-PCR, and the amounts of lipid mediators by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based lipidomics. We investigated the effect of the metabolite of EPA by in vivo and in vitro studies. Results: Eicosapentaenoic acid treatment reduced the accumulation of eosinophils in the airway and decreased mRNA expression of selected inflammatory mediators in the lung. Lipidomics clarified the metabolomic profile in the lungs. Among EPA-derived metabolites, 12-hydroxy-17,18-epoxyeicosatetraenoic acid (12-OH-17,18-EpETE) was identified as one of the major biosynthesized molecules; the production of this molecule was amplified by EPA administration and allergic inflammation. Intravenous administration of 12-OH-17,18-EpETE attenuated airway eosinophilic inflammation through downregulation of C-C chemokine motif 11 (CCL11) mRNA expression in the lungs. In vitro, this molecule also inhibited the release of CCL11 from human airway epithelial cells stimulated with interleukin-4. Conclusion: These results demonstrated that EPA alleviated airway eosinophilic inflammation through its conversion into bioactive metabolites. Additionally, our results suggest that 12-OH-17,18-EpETE is a potential therapeutic target for the management of asthma.

© 2019 American Society for Clinical Investigation. The neuronal and immune systems exhibit bidirectional interactions that play a critical role in tissue homeostasis, infection, and inflammation. Neuron-derived neuropeptides and neurotransmitters regulate immune cell functions, whereas inflammatory mediators produced by immune cells enhance neuronal activation. In recent years, accumulating evidence suggests that peripheral neurons and immune cells are colocalized and affect each other in local tissues. A variety of cytokines, inflammatory mediators, neuropeptides, and neurotransmitters appear to facilitate this crosstalk and positive-feedback loops between multiple types of immune cells and the central, peripheral, sympathetic, parasympathetic, and enteric nervous systems. In this Review, we discuss these recent findings regarding neuro-immune crosstalk that are uncovering molecular mechanisms that regulate inflammation. Finally, neuro-immune crosstalk has a key role in the pathophysiology of allergic diseases, and we present evidence indicating that neuro-immune interactions regulate asthma pathophysiology through both direct and indirect mechanisms.

© 2018 Elsevier Inc. How mycobiota influence immunity in gut distal sites is not well understood. Li et al. developed protocols for gut-targeted depletion of phagocytes and mycobiota-free mice to investigate the influence of fungi on gut-lung crosstalk. They reveal that intestinal phagocytes sense fungal dysbiosis and mediate gut-lung-directed immunity to aggravate allergic airway disease.

© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Group 2 innate lymphoid cells (ILC2s) play critical roles in the induction of type 2 inflammation, response to parasite infection, metabolic homeostasis, and tissue repair. These multifunctional roles of ILC2s are tightly controlled by complex regulatory systems in the local microenvironment, the disruption of which may cause various health problems. This review summarizes up-to-date knowledge regarding positive and negative regulators for ILC2s based on their function and signaling pathways, including activating cytokines (IL-33, IL-25; MAPK, NF-κB pathways), co-stimulatory cytokines (IL-2, IL-7, IL-9, TSLP; STAT5, IL-4; STAT6, TNF superfamily; MAPK, NF-κB pathways), suppressive cytokines (type1 IFNs, IFN-γ, IL-27; STAT1, IL-10, TGF-β), transdifferentiation cytokines (IL-12; STAT4, IL-1β, IL-18), lipid mediators (LTC4, LTD4, LTE4, PGD2; Ca2+-NFAT pathways, PGE2, PGI2; AC/cAMP/PKA pathways, LXA4, LTB4), neuropeptides (NMU; Ca2+-NFAT, MAPK pathways, VIP, CGRP, catecholamine, acetylcholine), sex hormones (androgen, estrogen), nutrients (butyrate; HDAC inhibitors, vitamins), and cell-to-cell interactions (ICOSL-ICOS; STAT5, B7-H6-NKp30, E-cadherin-KLRG1). This comprehensive review affords a better understanding of the regulatory network system for ILC2s, providing impetus to develop new treatment strategies for ILC2-related health problems.

© 2020 The Authors. Respirology Case Reports published by John Wiley & Sons Australia, Ltd on behalf of The Asian Pacific Society of Respirology. Novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 is rapidly spreading worldwide. A typical clinical manifestation of COVID-19 is pneumonia, which can progress to acute respiratory distress syndrome and respiratory failure. Recent studies have reported that COVID-19 is often accompanied by coagulopathy, and a significant number of patients with severe or critical COVID-19 develop concomitant thrombosis, including pulmonary embolism (PE). However, there are limited reports of the incidence of PE in non-severe COVID-19 patients. Here, we report a case of non-severe COVID-19 complicated by PE, which indicates that the possibility of PE should consistently be considered, even in non-severe cases of COVID-19 without any risk of thrombosis.

© 2020 The Author(s) This study investigated, using cycle threshold (Ct) qPCR values, the association between symptoms and viral clearance in 57 patients with asymptomatic/mild SARS-CoV-2 infection. Patients with olfactory/taste disorders (OTDs) exhibited lower qPCR Ct values and longer time to negative qPCR than those without OTDs, suggesting an association between OTDs and high viral burden.

© 2020 Japanese Society of Allergology TSLP is an epithelial cell-derived cytokine synthesized in response to various stimuli, including protease allergens and microorganisms like viruses and bacteria. Biological functions of TSLP require heterodimer formation between the TSLP receptor (TSLPR) and IL-7 receptor-α, which polarize dendritic cells to induce type 2 inflammation and directly expand and/or activate Th2 cells, group 2 innate lymphoid cells, basophils, and other immune cells. TSLP is thus considered a master regulator of type 2 immune responses at the barrier surfaces of skin and the respiratory/gastrointestinal tract. Indeed, genetic, experimental, and clinical evidence suggests that the TSLP-TSLPR pathway is associated with the pathogenesis of allergic diseases such as atopic dermatitis (AD) and asthma. Tezepelumab (AMG-157/MEDI9929) is a human anti-TSLP antibody that prevents TSLP-TSLPR interactions. A phase 2 trial for moderate to severe AD showed that a greater but not statistically significant percentage of tezepelumab-treated patients showed clinical improvements compared to the placebo group. A phase 2 trial for uncontrolled, severe asthma showed significant decreases in asthma exacerbation rate and improved pulmonary function and asthma control for tezepelumab-treated patients. Levels of biomarkers of type 2 inflammation, such as blood/sputum eosinophil counts and fraction of exhaled nitric oxide decreased, however, clinical efficacy was observed irrespective of the baseline levels of these biomarkers. A blockade of the TSLP-TSLPR pathway likely will exert significant clinical effects on AD, asthma, and other allergic diseases. The efficacy of anti-TSLP antibodies compared to other biologics needs to be further examined.

© 2020 Japanese Society of Allergology Background: Multiple phenotypes exist within the classification of severe asthma. However, characteristics of patients with not well-controlled severe asthma have not been well identified. Methods: Japanese patients with asthma (age ≥ 20 years) were enrolled at the Keio University Hospital and its affiliated hospitals in this observational study (Keio Severe Asthma Research Program). Among them, patients with severe asthma (those undergoing Global Initiative for Asthma [GINA] 2018 step 4 or 5 treatment) were included in this analysis and investigated clinical characteristics based on asthma control status. Results: Of the 154 patients (men, 46.8%; age, 60.1 ± 14.9 years), 87 (56.5%) had not well-controlled (partly controlled and uncontrolled) asthma (GINA step 4, 42 patients; step 5, 45 patients). Overall, there were no significant differences in clinical characteristics between patients with well-controlled and not well-controlled asthma. However, cluster analysis revealed that distinct 5 clusters (cluster 1, well-controlled; cluster 2, eosinophilic; cluster 3, non–type 2 inflammation; cluster 4, high periostin; and cluster 5, late-onset type 2 inflammation), and clusters 2–5 were not well-controlled. Among them, cluster 3 was characterized by low eosinophil counts, low periostin levels, and less frequent olfactory disturbance, and this cluster had the worst asthma control. Conclusions: Japanese patients with severe asthma were divided into well-controlled and not-well controlled asthma, and we confirmed heterogeneity of not well-controlled severe asthma. These patients, especially non-type 2 phenotype, require a further therapeutic approach. (University Hospital Medical Information Network Clinical Trials Registry, UMIN000002980)

© 2020 Canadian Cardiovascular Society Thrombosis, especially venous thromboembolism, is a complication often associated with coronavirus disease 2019 (COVID-19). However, there have been relatively few reports of arterial thrombosis. Here, we describe a case of non-severe COVID-19 in a patient with dilated cardiomyopathy. After admission, symptoms, laboratory data, and imaging findings improved, but D-dimer levels gradually increased. Contrast computed tomography and echocardiography revealed a left ventricular thrombus. Anticoagulant treatment diminished the thrombus, and the patient recovered and was discharged. Although a left ventricular thrombus is a rare COVID-19 complication, performing appropriate diagnostic tests could improve COVID-19 mortality in patients with dilated cardiomyopathy.

© 2020, The Author(s). Thymic stromal lymphopoietin (TSLP) is a critical upstream cytokine inducing type 2 inflammation in various diseases, including asthma and atopic dermatitis. Accumulating evidence suggests that TSLP can directly stimulate a variety of immune cells, such as dendritic cells (DCs), basophils, T cells, and group 2 innate lymphoid cells (ILC2s). However, which cell types directly respond to TSLP in vivo and how TSLP initiates type 2 inflammation has remained controversial. To define the precise role of TSLP in vivo, for the first time we generated multiple cell lineage-specific TSLP receptor-deficient mice to systematically dissect the cell-intrinsic requirements for TSLP responsiveness in type 2 inflammation in the lung. In papain-induced innate immune-mediated type 2 airway inflammation, TSLP directly stimulated ILC2s, but not basophils, leading to enhanced type 2 inflammation. On the other hand, in OVA-induced adaptive immune-mediated type 2 airway inflammation, TSLP principally acted on DCs and CD4 + T cells during the sensitization phase, but not basophils or ILC2s, and facilitated the development of Th2 cell-mediated airway inflammation. Together, these findings reveal that TSLP activates distinct immune cell cascades in the context of innate and adaptive immune-mediated type 2 inflammation.

Objective To investigate the similarities and differences between Coronavirus disease 2019 (COVID-19) and autoimmune and autoinflammatory rheumatic diseases characterised by hyperferritinaemia, such as antimelanoma differentiation-associated protein 5 (MDA5) autoantibody-positive dermatomyositis and adult Still’s disease. Methods We reviewed consecutive, newly diagnosed, untreated patients with COVID-19, anti-MDA5 dermatomyositis, or adult Still’s disease. We compared their clinical, laboratory, and radiological characteristics, including the prevalence of macrophage activation syndrome and lung involvement in each disease. Results The numbers of patients with COVID-19, anti-MDA5 dermatomyositis, and adult-onset Still’s disease with hyperferritinaemia (serum ferritin ≥500ng/dL) who were included for main analysis were 22, 14, and 59, respectively. COVID-19 and adult Still’s disease both featured hyperinflammatory status, such as high fever and elevated serum C-reactive protein, whereas COVID-19 and anti-MDA5 dermatomyositis both presented with severe interstitial lung disease and hypoxaemia. While two-thirds of the patients in each group met the criteria for macrophage-activated syndrome that is used in systemic juvenile idiopathic arthritis, the HScore, an indicator of haemophagocytic lymphohistiocytosis, was low in anti-MDA5 dermatomyositis and COVID-19 even in severe or critical cases. The findings of chest computed tomography were similar between COVID-19 and anti-MDA5 dermatomyositis. Conclusion COVID-19 shared clinical features with rheumatic diseases characterised by hyperferritinaemia, including anti-MDA5 dermatomyositis and adult Still’s disease. These findings should be investigated further in order to shed light on the pathogenesis of not only COVID-19 but also the aforementioned rheumatic diseases.

Background: The coronavirus disease 2019 (COVID-19) causes a wide spectrum of lung manifestations ranging from mild asymptomatic disease to severe respiratory failure. We aimed to clarify the characteristics of radiological and functional lung sequelae of COVID-19 patients described in follow-up period. Method: PubMed and EMBASE were searched on January 20th, 2021 to investigate characteristics of lung sequelae in COVID-19 patients. Chest computed tomography (CT) and pulmonary function test (PFT) data were collected and analyzed using one-group meta-analysis. Results: Our search identified 15 eligible studies with follow-up period in a range of 1–6 months. A total of 3066 discharged patients were included in these studies. Among them, 1232 and 1359 patients were evaluated by chest CT and PFT, respectively. The approximate follow-up timing on average was 90 days after either symptom onset or hospital discharge. The frequency of residual CT abnormalities after hospital discharge was 55.7% (95% confidential interval (CI) 41.2–70.1, I2 = 96.2%). The most frequent chest CT abnormality was ground glass opacity in 44.1% (95% CI 30.5–57.8, I2 = 96.2%), followed by parenchymal band or fibrous stripe in 33.9% (95% CI 18.4–49.4, I2 = 95.0%). The frequency of abnormal pulmonary function test was 44.3% (95% CI 32.2–56.4, I2 = 82.1%), and impaired diffusion capacity was the most frequently observed finding in 34.8% (95% CI 25.8–43.8, I2 = 91.5%). Restrictive and obstructive patterns were observed in 16.4% (95% CI 8.9–23.9, I2 = 89.8%) and 7.7% (95% CI 4.2–11.2, I2 = 62.0%), respectively. Conclusions: This systematic review suggested that about half of the patients with COVID-19 still had residual abnormalities on chest CT and PFT at about 3 months. Further studies with longer follow-up term are warranted.

INTRODUCTION: Pneumonia is one of the most important characteristics of coronavirus disease 2019 (COVID-19) and imaging findings of COVID-19 pneumonia are diverse and change over disease course. However, the detailed clinical course of organizing pneumonia (OP) caused by COVID-19 has not been clarified. PATIENT CONCERNS: A 60-year-old man and a 61-year-old woman diagnosed with mild COVID-19 were admitted to our hospital. Their respiratory symptoms were deteriorating even after initiating treatment with antiviral drugs. DIAGNOSIS: Chest X-rays and computed tomography scan showed a rapid progression of linear consolidation with reversed halo sign, distributed in subpleural and peri-bronchial regions. They also presented with pulmonary fibrosis findings, including traction bronchiectasis and marked lung volume reduction. They were diagnosed with rapidly progressing OP. INTERVENTIONS: They were treated with systemic corticosteroids. OUTCOMES: The patients' imaging findings and respiratory conditions improved rapidly without any adverse effects. CONCLUSION: Physicians should carefully monitor patients with COVID-19, as they can develop rapidly progressive and fibrotic OP, which respond to corticosteroids.