IgG4-related pleural disease diagnosed by thoracoscopic pleural biopsy: A case report.

Here we report a rare case of immunoglobulin G4 (IgG4)-related pleural disease diagnosed using a thoracoscopic pleural biopsy. A 66-year-old man was admitted to our hospital with right-dominant bilateral pleural effusions and gradually worsening dyspnoea. Chest radiographs revealed right-dominant pleural effusions, while chest computed tomography showed bilateral pleural effusions without parenchymal lesions. Although the bilateral pleural effusions were exudative with an increased number of lymphocytes, the definitive diagnosis was initially elusive. High IgG4 levels in the serum and pleural effusions were observed. A pathological evaluation of a right pleural biopsy specimen collected via video-assisted thoracoscopic surgery showed fibrosis-associated lymphoplasmacytic infiltration, 45-60 IgG4-positive plasma cells per high-power field, and an IgG4/immunoglobulin G ratio of 40%. Consequently, the patient was diagnosed with IgG4-related pleural disease. The bilateral pleural effusions improved after corticosteroid therapy.

SARS-CoV-2 co-detection with other respiratory pathogens-descriptive epidemiological study.

BACKGROUND: Co-detection of respiratory pathogens with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is poorly understood. This descriptive epidemiological study aimed to determine the effect of the interaction of different respiratory pathogens on clinical variables. METHODS: We retrospectively reviewed the results of comprehensive multiplex polymerase chain reaction (PCR) testing from November 2020 to March 2023 to estimate respiratory pathogen co-detection rates in Shinjuku, Tokyo. We evaluated the interactions of respiratory pathogens, particularly SARS-CoV-2, between observed and expected co-detection. We estimated the trend of co-detection with SARS-CoV-2 in terms of age and sex and applied a multiple logistic regression model adjusted for age, testing period, and sex to identify influencing factors between co-detection and single detection for each pathogen. RESULTS: Among 57,746 patients who underwent multiplex PCR testing, 10,516 (18.2%) had positive for at least one of the 22 pathogens. Additionally, 881 (1.5%) patients were confirmed to have a co-detection. SARS-CoV-2 exhibited negative interactions with adenovirus, coronavirus, human metapneumovirus, parainfluenza virus, respiratory syncytial virus, and rhino/enterovirus. SARS-CoV-2 co-detection with other pathogens occurred most frequently in patients of the youngest age group (0-4 years). A multiple logistic regression model indicated that younger age was the most influential factor for SARS-CoV-2 co-detection with other respiratory pathogens. CONCLUSION: The study highlights the prevalence of SARS-CoV-2 co-detection with other respiratory pathogens in younger age groups, necessitating further exploration of the clinical implications and severity of SARS-CoV-2 co-detection.

Autoimmune pulmonary alveolar proteinosis during the treatment of nonspecific interstitial pneumonia complicated by clinically amyopathic dermatomyositis: A case report.

A 46-year-old male was treated with corticosteroids for nonspecific interstitial pneumonia (NSIP). He was referred to our hospital and admitted for worsening dyspnea and diffuse ground-glass opacity on chest computed tomography (CT) during corticosteroid treatment. Gottron's sign was observed, and the patient was diagnosed with clinically amyopathic dermatomyositis on skin biopsy. We increased the corticosteroid dose and added immunosuppressive agents; however, the opacity on the chest CT worsened. Based on periodic-acid-Schiff-positive granular material in the bronchoalveolar lavage fluid and the presence of anti-GM-CSF antibodies, the patient was diagnosed with autoimmune pulmonary alveolar proteinosis (APAP). The concentration of anti-GM-CSF antibodies in preserved serum was also elevated when the patient was diagnosed with NSIP. Thus, we assumed that NSIP and APAP coexisted, and that APAP manifested during immunosuppressive therapy. When exacerbation is observed during the treatment of interstitial pneumonia with immunosuppressive agents, it is necessary to consider APAP.

Serum VEGF-A levels on admission in COVID-19 patients correlate with SP-D and neutrophils, reflecting disease severity: A prospective study.

BACKGROUND AND OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in significant global morbidity and mortality. This study aimed to investigate the clinical significance of serum vascular endothelial growth factor A (VEGF-A) in COVID-19 patients and its association with disease severity and pulmonary injury. METHODS: We prospectively collected data from 71 hospitalized COVID-19 patients between June 2020 and January 2021. Patients were classified as either mild or severe based on their oxygen requirements during hospitalization. Serum VEGF-A levels were measured using an ELISA kit. RESULTS: In comparison to mild cases, significantly elevated serum VEGF-A levels were observed in severe COVID-19 patients. Furthermore, VEGF-A levels exhibited a positive correlation with white blood cell count, neutrophil count, and lymphocyte count. Notably, serum surfactant protein-D (SP-D), an indicator of alveolar epithelial cell damage, was significantly higher in patients with elevated VEGF-A levels. CONCLUSION: These results suggest that elevated serum VEGF-A levels could serve as a prognostic biomarker for COVID-19 as it is indicative of alveolar epithelial cell injury caused by SARS-CoV-2 infection. Additionally, we observed a correlation between VEGF-A and neutrophil activation, which plays a role in the immune response during endothelial cell injury, indicating a potential involvement of angiogenesis in disease progression. Further research is needed to elucidate the underlying mechanisms of VEGF-A elevation in COVID-19.

Practical guide for the diagnosis and management of primary ciliary dyskinesia.

OBJECTIVE: Primary ciliary dyskinesia (PCD) is a relatively rare genetic disorder that affects approximately 1 in 20,000 people. Approximately 50 genes are currently known to cause PCD. In light of differences in causative genes and the medical system in Japan compared with other countries, a practical guide was needed for the diagnosis and management of Japanese PCD patients. METHODS: An ad hoc academic committee was organized under the Japanese Rhinologic Society to produce a practical guide, with participation by committee members from several academic societies in Japan. The practical guide including diagnostic criteria for PCD was approved by the Japanese Rhinologic Society, Japanese Society of Otolaryngology-Head and Neck Surgery, Japanese Respiratory Society, and Japanese Society of Pediatric Pulmonology. RESULTS: The diagnostic criteria for PCD consist of six clinical features, six laboratory findings, differential diagnosis, and genetic testing. The diagnosis of PCD is categorized as definite, probable, or possible PCD based on a combination of the four items above. Diagnosis of definite PCD requires exclusion of cystic fibrosis and primary immunodeficiency, at least one of the six clinical features, and a positive result for at least one of the following: (1) Class 1 defect on electron microscopy of cilia, (2) pathogenic or likely pathogenic variants in a PCD-related gene, or (3) impairment of ciliary motility that can be repaired by correcting the causative gene variants in iPS cells established from the patient's peripheral blood cells. CONCLUSION: This practical guide provides clinicians with useful information for the diagnosis and management of PCD in Japan.

LAG3 is an independent prognostic biomarker and potential target for immune checkpoint inhibitors in malignant pleural mesothelioma: a retrospective study.

BACKGROUND: Lymphocyte-activation gene 3 (LAG3) is an immune checkpoint receptor; novel LAG3 immune checkpoint inhibitors (ICIs) exhibit therapeutic activity in melanoma. The role of LAG3and ICIs of LAG3 are unknown in malignant pleural mesothelioma (MPM). This study aimed to uncover the prognostic landscape of LAG3 in multiple cancers and investigate the potential of using LAG3 as an ICIs target in patients with MPM. METHODS: We used The Cancer Genome Atlas (TCGA) cohort for assessing mRNA expression and our cohort for immunohistochemical expression. TCGA cohort were analyzed using the Wilcoxon rank-sum test to compare mRNA expression between normal and tumor tissues in multiple cancers. We used 86 MPM cases from TCGA and 38 MPM cases from our cohort to analyze the expression of LAG3 in tumor-infiltrating lymphocytes. The mean LAG3 mRNA expression was set as the cut-off and samples were classified as positive/negative for immunohistochemical expression. Overall survival (OS) of patients with MPM was determined using the Kaplan-Meier method based on LAG3 mRNA and immunohistochemical expression. OS analysis was performed using the multivariate Cox proportional hazards model. The correlation of LAG3 expression and mRNA expression of tumor immune infiltration cells (TIICs) gene markers were estimated using Spearman correlation. To identify factors affecting the correlation of LAG3 mRNA expression, a multivariate linear regression model was performed. RESULTS: LAG3 mRNA was associated with prognosis in multiple cancers. Elevated LAG3 mRNA expression was correlated with a better prognosis in MPM. LAG3 expression was detected immunohistochemically in the membrane of infiltrating lymphocytes in MPM. LAG3 immunohistochemical expression was correlated with a better prognosis in MPM. The multivariate Cox proportional hazards model revealed that elevated LAG3 immunohistochemical expression indicated a better prognosis. In addition, LAG3 mRNA expression was correlated with the expression of various gene markers of TIICs, the most relevant to programmed cell death 1 (PD-1) with the multivariate linear regression model in MPM. CONCLUSIONS: LAG3 expression was correlated with prognosis in multiple cancers, particularly MPM; LAG3 is an independent prognostic biomarker of MPM. LAG3 regulates cancer immunity and is a potential target for ICIs therapy. PD-1 and LAG3 inhibitors may contribute to a better prognosis in MPM. TRIAL REGISTRATION: This study was registered with UMIN000049240 (registration day: August 19, 2022) and approved by the Institutional Review Board (approval date: August 22, 2022; approval number: 2022-0048) at Tokyo Women's Medical University.

Clinical characteristics and treatment outcomes of severe asthma patients with a history of multiple biologic drugs use.

BACKGROUND: Asthma control has been shown to improve after clinical use of molecular-targeted biologic drugs. Although most patients have shown favorable responses to biologic drugs, some individuals need to switch to another biologic drug. To date, limited data are available regarding patients who received multiple biologic drugs. OBJECTIVE: We aimed to evaluate the characteristics and outcomes of patients treated with multiple biologic drugs. METHODS: We reviewed severe asthma patients who received biologic drugs between May 2009 and September 2019. Clinical characteristics of patients and changes in annualized asthma exacerbation rates, asthma control test (ACT), and oral corticosteroid (OCS) dose, before and after the use of the final biologic drug, were evaluated. RESULTS: Of the 105 patients who received biologic drugs, 20 patients received multiple biologic drugs. Twelve patients received two biologic drugs, six received three, and two received four. Patients who received multiple biologic drugs tended to have a significantly higher number of allergic or eosinophilic airway comorbidities (allergic rhinitis: p = 0.02, chronic rhinosinusitis with nasal polyps: p < 0.001). Approximately half of the patients changed to different treatments due to uncontrolled comorbidities. Annualized exacerbation rates, ACT, and OCS dose significantly improved after the latest biologic drug use (p = 0.035, p < 0.001, and p = 0.038, respectively). CONCLUSIONS: The results of this study indicated that allergic and eosinophilic airway comorbidities should be considered during the selection of biologic drugs. Furthermore, most patients who received multiple biologic drugs achieved disease control after switching to the optimal biologic drug.

Nationwide survey of refractory asthma with bronchiectasis by inflammatory subtypes.

RATIONALE: Bronchiectasis and bronchiolitis are differential diagnoses of asthma; moreover, they are factors associated with worse asthma control. OBJECTIVE: We determined clinical courses of bronchiectasis/bronchiolitis-complicated asthma by inflammatory subtypes as well as factors affecting them. METHODS: We conducted a survey of refractory asthma with non-cystic fibrosis bronchiectasis/bronchiolitis in Japan. Cases were classified into three groups, based on the latest fractional exhaled NO (FeNO) level (32 ppb for the threshold) and blood eosinophil counts (320/µL for the threshold): high (type 2-high) or low (type 2-low) FeNO and eosinophil and high FeNO or eosinophil (type 2-intermediate). Clinical courses in groups and factors affecting them were analysed. RESULTS: In total, 216 cases from 81 facilities were reported, and 142 were stratified: 34, 40 and 68 into the type 2-high, -intermediate and -low groups, respectively. The frequency of bronchopneumonia and exacerbations requiring antibiotics and gram-negative bacteria detection rates were highest in the type 2-low group. Eighty-seven cases had paired latest and oldest available data of FeNO and eosinophil counts; they were analysed for inflammatory transition patterns. Among former type 2-high and -intermediate groups, 32% had recently transitioned to the -low group, to which relatively low FeNO in the past and oral corticosteroid use contributed. Lastly, in cases treated with moderate to high doses of inhaled corticosteroids, the frequencies of exacerbations requiring antibiotics were found to be higher in cases with more severe airway lesions and lower FeNO. CONCLUSIONS: Bronchiectasis/bronchiolitis-complicated refractory asthma is heterogeneous. In patients with sputum symptoms and low FeNO, airway colonisation of pathogenic bacteria and infectious episodes are common; thus, corticosteroids should be carefully used.

A case of lung intravascular large B cell lymphoma developed with respiratory failure rescued by corticosteroid prior to definite diagnosis.

A 56-year-old man complained progressive dyspnea, fatigue and fever for one month. His chest CT exhibited faint ground-glass opacities, and the levels of serum LDH and soluble interleukin 2 receptor were markedly elevated. Positron emission tomography (PET) showed high uptake of 18-fluoro deoxy glucose (18FDG) only on both lungs. We performed transbronchial lung biopsies (TBLB) for the diagnosis. After bronchoscopy, he had prolonged hypoxemia. Because defects of 99m-Technetium macroaggregated albumin (99mTc-MAA) in pulmonary blood flow scintigraphy were consistent with the distribution of 18FDG uptake in PET, we speculated that the presence of intravascular lymphoma (IVL) cells in the capillaries might have behaved like tumor embolism. We started rescue by prednisolone based on treatment of lymphoma. As a result, his hypoxemia was gradually improved. Histological findings in TBLB specimen showed that CD20+CD79+Bcl-2+c-myc+ lymphoma cells were localized to small vessel lumina in alveoli and bronchioles, and he was definitely diagnosed with lung intravascular large B cell lymphoma (IVLBCL). He was treated with complete cyclophosphamide, doxorubicin, vincristine, and prednisolone with rituximab (R-CHOP) in combination with intrathecal methotrexate injection. After eight cycles of R-CHOP and three times of intrathecal methotrexate, 18FDG uptake of PET on both lungs completely disappeared, achieving complete metabolic remission. We experienced a rare case of lung IVLBCL developed with respiratory failure successfully rescued by prednisolone prior to definite diagnosis.

Analysis of the diagnosis of Japanese patients with primary ciliary dyskinesia using a conditional reprogramming culture.

BACKGROUND: Primary ciliary dyskinesia (PCD) is diagnosed through multiple methods, including transmission electron microscopy (TEM), a high-speed video microscopy analysis (HSVA), immunofluorescence (IF), and genetic testing. A primary cell culture has been recommended to avoid the misdiagnosis of secondary ciliary dyskinesia derived from infection or inflammation and improve diagnostic accuracy. However, primary cells fail to differentiate into ciliated cells through repeated passages. The conditional reprogramming culture (CRC) method, a combination of a Rho-kinase inhibitor and fibroblast feeder cells, has been applied to cystic fibrosis. The goal of this study was to evaluate the value of CRC in diagnosing PCD in Japanese patients. METHODS: Eleven patients clinically suspected of having PCD were included. Airway epithelial cells were obtained from an endobronchial forceps biopsy and cultured at the air-liquid interface (ALI) combined with CRC. Ciliary movement, ultrastructure, and mutated ciliary protein evaluation were performed using HSVA, TEM, and IF, respectively. Genetic testing was performed on some patients. RESULTS: CRC yielded dense and well-differentiated ciliated cells with a high success rate (∼90%). In patients with PCD, the ciliary ultrastructure phenotype (outer dynein arm defects or normal ultrastructure) and IF findings (absence of the mutated ciliary protein) were confirmed after CRC. In DNAH11-mutant cases with normal ultrastructure by TEM, the HSVA revealed stiff and hyperfrequent ciliary beating with low bending capacity in CRC-expanded cells, thereby supporting the diagnosis. CONCLUSIONS: CRC could be a potential tool for improving diagnostic accuracy and contributing to future clinical and basic research in PCD.

Tryptase and IL-33 in Bronchoalveolar Lavage Fluid May Predict the Types of Eosinophilic Pneumonia and Disease Recurrence.

INTRODUCTION: Eosinophilic pneumonia (EP) is characterized by a marked accumulation of eosinophils in the lungs and blood. Eosinophils and mast cells play an important role in the pathogenesis of EP via release of biomarkers such as tryptase and interleukin (IL)-33. However, the potential role of these biomarkers is not fully understood. OBJECTIVES: We aimed to evaluate the differences among the levels of tryptase and IL-33 in bronchoalveolar lavage fluid (BALF) from several types of EP. We evaluated the differences between the levels of these biomarkers in the recurrent and nonrecurrent cases. METHOD: We prospectively collected the clinical data of patients with EP, diagnosed between 2006 and 2015 in our institution. Bronchoscopy was performed before steroid treatment; BALF was collected. The clinical characteristics of EP patients and the levels of tryptase and IL-33 in BALF were evaluated. RESULTS: We enrolled 15 patients with chronic EP (CEP), 5 with acute EP (AEP), 10 with drug-induced EP, and 6 with angiitis-related EP. Tryptase levels in the CEP group were significantly higher than that in the drug-induced EP group (p = 0.048), while the AEP group had the highest IL-33 levels. Recurrence of EP was noted in 67% of patients with CEP. The levels of tryptase and IL-33 were notably higher in the recurrent cases than that in the nonrecurrent CEP group (p = 0.004, p = 0.04, respectively). Furthermore, there was a positive correlation between the levels of tryptase and IL-33 in the BALF of patients with CEP (ρ = 0.69, p = 0.004). CONCLUSIONS: Tryptase and IL-33 in BALF are useful biomarkers for the assessment of EP types. These biomarkers could be used to predict disease recurrence.

Analysis of the clinical features of Japanese patients with primary ciliary dyskinesia.

OBJECTIVE: Primary ciliary dyskinesia (PCD) is a rare hereditary disease. Most reports of PCD in Japan are case reports, and clinical analysis has not been performed. Differences in the causative genes might affect the clinical features in different ethnic groups. The purpose of this study was to clarify the clinical features of Japanese patients with PCD. METHODS: We performed a retrospective chart review of PCD patients seen at Mie University Hospital and patients whose blood samples were sent to us for genetic analysis from 2011 to 2020. Data on the following items were collected and analyzed: age at first visit to the hospital, age at diagnosis of PCD, process of referral to our facility, chief complaint, situs status, PrImary CiliARy DyskinesiA Rule (PICADAR) score, nasal nitric oxide concentration, otoscopic findings, rhinoscopic findings, and paranasal computed tomography scan findings. RESULTS: Sixty-seven patients (24 male, 43 female) were diagnosed with PCD during the study period. Age at diagnosis ranged from 2 months to 69 years (median, 17 years). Respiratory symptoms (77%) were the most common complaint, followed by nasal (15%) and aural (8%) symptoms. Situs inversus was present in 17 (25%) cases. Only 2 cases had congenital cardiac anomalies. The mean PICADAR score was 7.3 (range, 3-14) points. Approximately 50% of tympanic membranes showed retraction, suggesting otitis media with effusion. The mean Lund-Mackay score was 12.8 (range, 7-17) points, suggesting that the radiographic findings were not always severe. There was no significant difference in the total Lund-Mackay score between patients with and without situs inversus (12.7 vs. 12.6, respectively). CONCLUSION: Situs inversus was present in 25% of Japanese PCD patients, which is much lower than observed in other countries. This is a result of differences in the major disease-causing genes. The general rule that "situs inversus is observed in approximately 50% of PCD patients" cannot be applied, at least, in Japanese PCD patients.

Less airway inflammation and goblet cell metaplasia in an IL-33-induced asthma model of leptin-deficient obese mice.

BACKGROUND: Obesity-associated asthma is a phenotype of severe asthma. Late-onset, non-eosinophilic and female-dominant phenotype is highly symptomatic and difficult to treat. Leptin, an adipokine, exerts an immunomodulatory effect. IL-33 associated with innate immunity induces type 2 inflammation and is present in adipose tissue. The purpose of this study was to elucidate the pathogenesis of obesity-associated asthma by focusing on the interaction between leptin and IL-33. METHODS: In leptin-deficient obese (ob/ob) and wild-type mice, IL-33 was instilled intranasally on three consecutive days. In part of the mice, leptin was injected intraperitoneally prior to IL-33 treatment. The mice were challenged with methacholine, and airway hyperresponsiveness (AHR) was assessed by resistance (Rrs) and elastance (Ers) of the respiratory system using the forced oscillation technique. Cell differentiation, IL-5, IL-13, eotaxin, keratinocyte-derived chemokine (KC) in bronchoalveolar lavage fluid (BALF) and histology of the lung were analyzed. For the in vitro study, NCI-H292 cells were stimulated with IL-33 in the presence or absence of leptin. Mucin-5AC (MUC5AC) levels were measured using an enzyme-linked immunosorbent assay. RESULTS: Ob/ob mice showed greater Rrs and Ers than wild-type mice. IL-33 with leptin, but not IL-33 alone, enhanced Ers rather than Rrs challenged with methacholine in ob/ob mice, whereas it enhanced Rrs alone in wild-type mice. IL-33-induced eosinophil numbers, cytokine levels in BALF, eosinophilic infiltration around the bronchi, and goblet cell metaplasia were less in ob/ob mice than in wild-type mice. However, leptin pretreatment attenuated these changes in ob/ob mice. MUC5AC levels were increased by co-stimulation with IL-33 and leptin in vitro. CONCLUSIONS: Ob/ob mice show innate AHR. IL-33 with leptin, but not IL-33 alone, induces airway inflammation and goblet cell metaplasia and enhances AHR involving peripheral airway closure. This is presumably accelerated by mucus in ob/ob mice. These results may explain some aspects of the pathogenesis of obesity-associated asthma.

Characteristics of patients with severe asthma who experienced treatment failure with omalizumab.

BACKGROUND: Omalizumab, an anti-IgE antibody, has been widely used in many countries, including Japan. However, some patients do not respond to omalizumab, and the cause of treatment failure has not been fully elucidated. OBJECTIVE: This study aimed to evaluate the characteristics of adult asthma patients who failed to achieve disease control with omalizumab in a real-world setting. METHODS: We retrospectively reviewed the medical records of patients in Tokyo Women's Medical University Hospital between March 2009 and May 2016. The patient characteristics and factors for treatment failure with omalizumab were evaluated, as were treatment alternatives after discontinuation of omalizumab. RESULTS: In total, 59 patients were included in this study. The omalizumab-ineffective group had a significantly higher number of patients with eosinophilic sinusitis (P = 0.001) and eosinophilic otitis media (P = 0.023) than the omalizumab-effective group. A multivariate analysis revealed that both eosinophilic chronic rhinosinusitis (odds ratio: 23.4; P = 0.011) and eosinophilic otitis media (odds ratio: 6.71; P = 0.039) were associated with treatment failure with omalizumab. Most patients with eosinophilic comorbidities of the ear, nose, and throat (ENT) in the omalizumab-ineffective group received mepolizumab or benralizumab as alternative therapy, following which disease control was achieved. CONCLUSION: Eosinophilic comorbidities of the ENT may affect treatment failure with omalizumab in patients with severe asthma. Anti-interleukin-5 antibody or anti-interleukin-5Rα antibody rather than anti-IgE antibody should be considered as an additional therapy for patients with severe asthma who have eosinophilic comorbidities of the ENT.

Multifaceted analysis of Japanese cases of primary ciliary dyskinesia: Value of immunofluorescence for ciliary protein detection in patients with DNAH5 and DNAH11 mutations.

Multifaceted analysis is recommended for the diagnosis of primary ciliary dyskinesia (PCD). A 31-year-old woman had situs inversus, bronchiectasis, family history of PCD, and compound heterozygous mutations in DNAH5. Her cilia were immotile. Defects in the outer dynein arms were revealed by transmission electron microscopy and loss of DNAH5 proteins in the entire length of axonemes using immunofluorescence (IF). A 17-year-old boy had bronchiectasis and heterozygous mutations in DNAH11. His cilia were motile with normal ultrastructure. The loss of DNAH11 proteins at the proximal region of cilia was revealed by IF. IF could be useful to support PCD diagnosis.

Polymerase-chain reaction testing to prevent hospital-acquired severe acute respiratory syndrome coronavirus 2 infection in Shinjuku, an epicenter in Tokyo: The Tokyo Women's Medical University model.

Hospital-acquired severe acute respiratory virus coronavirus 2 (SARS-CoV-2) infection is a healthcare challenge. We hypothesized that polymerase chain reaction testing of symptomatic triaged outpatients and all inpatients before hospitalization in Shinjuku, a coronavirus disease 2019 (COVID-19) epicenter in Tokyo, using the Tokyo Women's Medical University (TMWU) model would be feasible and efficient at preventing COVID-19. This retrospective study enrolled 2981 patients from March to May 2020. The prevalence of SARS-CoV-2 infection was 1.81% (95% credible interval [CI]: 0.95-3.47%) in triaged symptomatic outpatients, 0.04% (95% CI: 0.0002-0.2%) in scheduled asymptomatic inpatients, 3.78% (95% CI: 1.82-7.26%) in emergency inpatients, and 2.4% (95% CI: 1.49-3.82%) in symptomatic patients. There were no cases of hospital-acquired SARS-CoV-2 infection. This shows that the TWMU model could prevent hospital-acquired SARS-CoV-2 infection and is feasible and effective in reducing the impact of SARS-CoV-2 infection in the hospitals.

A case of pulmonary infarction induced by undiagnosed HIV.

A 25-year-old Chinese man visited our institution due to fever and left chest pain. A chest CT showed infiltrative shadows with pleural effusion. Despite antibiotics treatment, his symptoms gradually worsened. The contrast CT showed deterioration of infiltrative shadows with thromboembolism in pulmonary arteries, suggesting pulmonary infarction. Thereafter, his HIV test turned out to be positive. His symptoms and radiological findings improved after initiation of an anticoagulant therapy. No known risk factors for thromboembolism were identified except HIV infection. The possibility of pulmonary thrombosis should be noted when the HIV patient with acute chest pain and pneumonia-like infiltrative shadow is seen.

Coexistence of diffuse panbronchiolitis and sarcoidosis revealed during splenectomy: a case report.

BACKGROUND: Sarcoidosis is a systemic granulomatous disease caused by CD4+ cell-dominant inflammation. Meanwhile, diffuse panbronchiolitis is a chronic inflammatory respiratory disease predominantly caused by CD8+ lymphocytes and neutrophils. Herein, we report a rare case of sarcoidosis in which the clinical presentation had become evident as diffuse panbronchiolitis after splenectomy for sarcoidosis. CASE PRESENTATION: A 23-year-old Japanese woman was referred to our hospital due to splenomegaly of unknown etiology. Upon admission, chest computed tomography scan revealed centrilobular and randomly distributed small nodules in both lungs. Bronchoalveolar lavage revealed a high proportion of lymphocytes and a decreased CD4/CD8 ratio. However, the biopsy specimens obtained from both the liver and lungs revealed noncaseating epithelioid granulomas, which confirmed the diagnosis of sarcoidosis. The patient underwent splenectomy due to progressive cytopenia and high risk of splenic rupture. After the surgery, the condition of the patient was consistently good for 3 months. Then, she gradually developed productive cough and dyspnea. Both sinus and chest computed tomography scan revealed chronic paranasal sinusitis and deterioration of centrilobular nodules in both lung fields, respectively. The second bronchoalveolar lavage revealed a high proportion of neutrophils, and the bronchoalveolar lavage fluid tested positive for Hemophilus influenzae. The titer of cold agglutinin was elevated, thereby confirming the diagnosis of diffuse panbronchiolitis. On the basis of the clinical and radiological findings, the condition of the patient improved with low-dose macrolide therapy for 3 months. CONCLUSIONS: The coexistence of sarcoidosis and diffuse panbronchiolitis has not been previously reported, and the hidden profiles of diffuse panbronchiolitis may have been revealed by splenectomy.

A case of lymphangioleiomyomatosis with diffuse large B-cell lymphoma: Usefulness of FDG-PET.

Lymphangioleiomyomatosis (LAM) is characterized by cystic lung disease, abdominal tumor and involvement of the axial lymph nodes. We report a very rare case of LAM with malignant lymphoma. A 51-year-old female had medical history of recurrent pneumothorax and nephrectomy for a left renal angiomyolipoma and was diagnosed with LAM by video-assisted thoracoscopic surgery at the age of 30. She presented with left neck mass. Computed tomography and magnetic response imaging showed multiple enlarged cervical lymph nodes. 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) showed abnormal uptake in the mass. We suspected a malignant tumor or extrapulmonary lesion of LAM, and performed surgical biopsy. Pathologically, diffuse large B-cell lymphoma was diagnosed, but LAM was not detected. After she received six cycles of R-CHOP chemotherapy, FDG-PET turned negative and complete metabolic response was achieved. As LAM is reported to be silent for FDG-PET, unusual uptake of FDG is useful for identifying other neoplasms. For this case, FDG-PET was useful for the differential diagnosis and therapeutic evaluation.