Infectious respiratory pathogens among patients with acute exacerbation of idiopathic pulmonary fibrosis during the coronavirus disease 2019 pandemic in Japan.

BACKGROUND: Few studies have investigated the prevalence of pathogens in patients with acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF), specifically, the interactions between respiratory pathogens and AE-IPF during the coronavirus disease 2019 (COVID-19) pandemic. OBJECTIVES: We aimed to analyze pathogens in patients with AE-IPF between September 2020 and December 2022. METHODS: This retrospective observational study was conducted at our hospital between September 2020 and December 2022. In patients with AE-IPF, pre-hospitalization polymerase chain reaction (PCR) tests for respiratory pathogens, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), were performed using multiplex PCR or Smart Gene assay with nasopharyngeal swab specimens. Microbiological assays, including Gram staining, sputum cultures, blood cultures, and urinary antigen tests for Streptococcus pneumoniae and Legionella pneumophila, were also performed. RESULTS: Forty-nine patients with AE-IPF were included. The median age was 75 years old and 42 (86 %) were male. Only one of the 49 patients (2 %) was positive for SARS-CoV-2. Two of 28 patients (7 %) were positive for human rhinovirus/enterovirus. No bacteria were detected in sputum culture, blood culture, or urinary antigen tests. CONCLUSIONS: The detection frequency of SARS-CoV-2 infection in patients with AE-IPF was lower than that of human rhinovirus/enterovirus. Continuous analysis for the presence of pathogens is necessary for appropriate infection control because respiratory viruses may increase as the coronavirus pandemic subsides.

Epidemiologic evaluation of pulmonary paragonimiasis in Japan using a Japanese nationwide administrative database.

BACKGROUND: Paragonimiasis is a parasitic disease primarily contracted through consumption of undercooked freshwater crustaceans or wild boar meat. Large-scale nationwide epidemiological data on paragonimiasis are lacking. In this study, we aimed to investigate the nationwide epidemiology of hospitalized patients with paragonimiasis in Japan using a comprehensive nationwide Japanese administrative database. METHODS: We evaluated the Japanese Diagnosis Procedure Combination (DPC) data of patients diagnosed with pulmonary paragonimiasis between April 1, 2012 and March 30, 2020. The patients' address and information, including age, sex, treatment (medication: praziquantel; surgery: open thoracotomy or intracranial mass extirpation), Japan coma scale, comorbidities, and length of hospital stay, were extracted. RESULTS: Of the 49.6 million hospitalized patients, data were extracted on 73 patients with paragonimiasis, of whom 36 were male and 37 were female. The mean age was 49.7 years and the mean length of stay was 12.5 days. The most frequent comorbidity was pleural effusion (31.5 %), followed by pneumothorax (13.7 %). The sites of ectopic paragonimiasis in organs other than the lung included the liver (5.5 %), skin (4.1 %), and brain (2.7 %). Geographically, most patients were from the Kyushu region (54.8 %), followed by the Kanto region (22.0 %). Fukuoka Prefecture had the highest number of patients (22.0 %) by prefecture. During the study period, an average of 9.1 patients/year were hospitalized with lung paragonimiasis in Japan. CONCLUSION: Paragonimiasis has not completely disappeared in Japan; thus, physicians should be aware of paragonimiasis in the Kyushu region, especially in the Fukuoka Prefecture.

Sarcoidosis Associated with Enlarged Mediastinal Lymph Nodes with the Detection of Streptococcus gordonii and Cutibacterium acnes Using a Clone Library Method.

A 77-year-old Japanese woman with mediastinal lymphadenopathy and uveitis was diagnosed with sarcoidosis. The bacterial flora in biopsied samples from mediastinal lymph nodes was analyzed using a clone library method with Sanger sequencing of the 16S rRNA gene, and Streptococcus gordonii (52 of 71 clones) and Cutibacterium acnes (19 of 71 clones) were detected. No previous study has conducted a bacterial floral analysis using the Sanger method for the mediastinal lymph node in sarcoidosis, making this case report the first to document the presence of S. gordonii and C. acnes in the mediastinal lymph node of a patient with sarcoidosis.

Clinical factors associated with viral shedding time of SARS-CoV-2 Omicron variant in Japan.

The Omicron variant of severe acute respiratory syndrome coronavirus 2 exhibits increased infectivity compared with all prior variants, and the timing of quarantine release should be carefully considered. However, to date, only two Chinese studies have analyzed the association between the viral shedding time (VST) and risk factors among patients infected with the Omicron variant. These studies included only limited numbers of severe cases and no analysis of underlying diseases and immunosuppressive drug use. Therefore, the current study aimed to analyze them in Japan. This retrospective observational study was conducted at the University of Occupational and Environmental Health, Japan, from January 2022 to October 2022 and included 87 hospitalized patients and 305 healthcare workers (HCWs) with coronavirus 2019 (COVID-19). In comparison with HCWs, hospitalized patients were significantly older and had a higher proportion of severe COVID-19 cases and significantly longer VST. A simple regression analysis showed that severe, current, or ex-smoking status, cardiovascular diseases, chronic kidney disease, and use of corticosteroids for underlying diseases were significantly correlated with a longer VST. Moreover, multiple linear regression analysis revealed that cardiovascular diseases, chronic kidney disease, and corticosteroid use were significantly associated with a longer VST. Therefore, COVID-19 patients with these underlying diseases may require a longer isolation period and the timing of quarantine release should be carefully considered.

Difficulty differentiating primary mediastinal classical Hodgkin lymphoma from inflammatory myofibroblastic tumor: A case report.

A 20-year-old Japanese man visited our hospital because an enlarged mediastinal shadow had been detected on chest x-ray. Chest computed tomography revealed a large mediastinal mass with multiple lymph node enlargement, pericardial effusion, and bilateral pleural effusion. He was diagnosed with inflammatory myofibroblastic tumor (IMT) based on a thoracoscopic tumor biopsy. Initial corticosteroid and celecoxib treatment was only partially effective; therefore, additional tumor rebiopsy and left axillary lymph node biopsy were performed. Based on the findings, the patient was rediagnosed with classical Hodgkin lymphoma (CHL). To date, there has only been one report of a case initially diagnosed as IMT and rediagnosed as CHL, as in our case, and only three reports of malignant lymphoma mimicking IMT. When IMT is suspected based on pathological findings and subsequently with treatment failure, possible CHL and performing rebiopsy should be considered.

Altered Polarization and Impaired Phagocytic Activity of Lung Macrophages in People With Human Immunodeficiency Virus and Chronic Obstructive Pulmonary Disease.

BACKGROUND: People with human immunodeficiency virus (PWH) have an increased risk of developing chronic obstructive pulmonary disease (COPD). METHODS: We phenotyped lung macrophages in 4 subgroups-M1 (CD40+CD163-), M2 (CD40-CD163+), double positives (CD40+CD163+), and double negatives and (CD40-CD163-)-and we determined their phagocytic capacity in PWH with and without COPD. RESULTS: People with human immunodeficiency virus with COPD have more double-negative macrophages (84.1%) versus PWH without (54.3%) versus controls (23.9%) (P=.004) and reduced phagocytosis (P=.012). Double-negative macrophages had the worst phagocytic capacity (P<.001). CONCLUSIONS: People with human immunodeficiency virus with COPD have an abundance of nonpolarized macrophages, which have poor phagocytic capacity and therefore predispose PWH to increased risk of disease progression.

Macrophages with reduced expressions of classical M1 and M2 surface markers in human bronchoalveolar lavage fluid exhibit pro-inflammatory gene signatures.

The classical M1/M2 polarity of macrophages may not be applicable to inflammatory lung diseases including chronic obstructive pulmonary disease (COPD) due to the complex microenvironment in lungs and the plasticity of macrophages. We examined macrophage sub-phenotypes in bronchoalveolar lavage (BAL) fluid in 25 participants with CD40 (a M1 marker) and CD163 (a M2 marker). Of these, we performed RNA-sequencing on each subtype in 10 patients using the Illumina NextSeq 500. Approximately 25% of the macrophages did not harbor classical M1 or M2 surface markers (double negative, DN), and these cells were significantly enriched in COPD patients compared with non-COPD patients (46.7% vs. 14.5%, p < 0.001). 1886 genes were differentially expressed in the DN subtype compared with  all other subtypes at a 10% false discovery rate. The 602 up-regulated genes included 15 mitochondrial genes and were enriched in 86 gene ontology (GO) biological processes including inflammatory responses. Modules associated with cellular functions including oxidative phosphorylation were significantly down-regulated in the DN subtype. Macrophages in the human BAL fluid, which were negative for both M1/M2 surface markers, harbored a gene signature that was pro-inflammatory and suggested dysfunction in cellular homeostasis. These macrophages may contribute to the pathogenesis and manifestations of inflammatory lung diseases such as COPD.

Abundance of Non-Polarized Lung Macrophages with Poor Phagocytic Function in Chronic Obstructive Pulmonary Disease (COPD).

Lung macrophages are the key immune effector cells in the pathogenesis of Chronic Obstructive Pulmonary Disease (COPD). Several studies have shown an increase in their numbers in bronchoalveolar lavage fluid (BAL) of subjects with COPD compared to controls, suggesting a pathogenic role in disease initiation and progression. Although reduced lung macrophage phagocytic ability has been previously shown in COPD, the relationship between lung macrophages' phenotypic characteristics and functional properties in COPD is still unclear. (1) Methods: Macrophages harvested from bronchoalveolar lavage (BAL) fluid of subjects with and without COPD (GOLD grades, I-III) were immuno-phenotyped, and their function and gene expression profiles were assessed using targeted assays. (2) Results: BAL macrophages from 18 COPD and 10 (non-COPD) control subjects were evaluated. The majority of macrophages from COPD subjects were non-polarized (negative for both M1 and M2 markers; 77.9%) in contrast to controls (23.9%; p < 0.001). The percentages of these non-polarized macrophages strongly correlated with the severity of COPD (p = 0.006) and current smoking status (p = 0.008). Non-polarized macrophages demonstrated poor phagocytic function in both the control (p = 0.02) and COPD (p < 0.001) subjects. Non-polarized macrophages demonstrated impaired ability to phagocytose Staphylococcus aureus (p < 0.001). They also demonstrated reduced gene expression for CD163, CD40, CCL13 and C1QA&B, which are involved in pathogen recognition and processing and showed an increased gene expression for CXCR4, RAF1, amphiregulin and MAP3K5, which are all involved in promoting the inflammatory response. (3) Conclusions: COPD is associated with an abundance of non-polarized airway macrophages that is related to the severity of COPD. These non-polarized macrophages are predominantly responsible for the poor phagocytic capacity of lung macrophages in COPD, having reduced capacity for pathogen recognition and processing. This could be a key risk factor for COPD exacerbation and could contribute to disease progression.

Lung Macrophage Functional Properties in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is caused by the chronic exposure of the lungs to toxic particles and gases. These exposures initiate a persistent innate and adaptive immune inflammatory response in the airways and lung tissues. Lung macrophages (LMs) are key innate immune effector cells that identify, engulf, and destroy pathogens and process inhaled particles, including cigarette smoke and particulate matter (PM), the main environmental triggers for COPD. The number of LMs in lung tissues and airspaces is increased in COPD, suggesting a potential key role for LMs in initiating and perpetuating the chronic inflammatory response that underpins the progressive nature of COPD. The purpose of this brief review is to discuss the origins of LMs, their functional properties (chemotaxis, recruitment, mediator production, phagocytosis and apoptosis) and changes in these properties due to exposure to cigarette smoke, ambient particulate and pathogens, as well as their persistent altered functional properties in subjects with established COPD. We also explore the potential to therapeutically modulate and restore LMs functional properties, to improve impaired immune system, prevent the progression of lung tissue destruction, and improve both morbidity and mortality related to COPD.

Two Cases of Tuberous Sclerosis Complex Suggestive of Complicating Multifocal Micronodular Pneumocyte Hyperplasia: A Case Report.

Multifocal micronodular pneumocyte hyperplasia (MMPH) is pathologically characterized by multifocal nodular hyperplasia of type Ⅱ pneumocyte-like cells. MMPH is usually complicated with tuberous sclerosis complex (TSC). MMPH patients tend to be asymptomatic or only slightly symptomatic. MMPH tends to progress slowly and needs no treatment. We herein describe two cases of MMPH with its characteristic radiological features and clinical manifestations of TSC. Case 1: a 20-year-old female with definitive TSC in infancy. Chest CT at the age of 18 revealed multiple nodular opacities and ground-glass attenuations in a scattered and random distribution in the bilateral lungs. Case 2: a 44-year-old female with probable TSC at 36 years of age. Chest CT at the age of 43 showed random areas of small ground-glass attenuations, predominantly in the upper lung fields. Case 1 and Case 2 have had no respiratory symptoms or radiographic changes in the recent two years and four years, respectively. Although pathological examinations of the lung were not performed because consent for surgical lung biospies was unobtainable, we considered that these pulmonary manifestations were most likely MMPH with TSC because of these characteristic radiographical findings of multiple nodular opacities and ground-glass attenuations of 10 mm or less in size and their scattered distribution, and because there have been no abnormal laboratory data or changes in their chest radiological findings for years. Neither patient is under treatment for pulmonary lesions. Although MMPH is a rare disease, multiple nodules and ground-glass attenuations on lung imaging findings should be considered as pulmonary manifestations in patients with TSC.

An Autopsy Case Report of Adult T-cell Leukemia Accompanied by Rheumatoid Arthritis Mimicking Diffuse Panbronchiolitis.

A 50-year-old female with a history of chronic sinusitis and rheumatoid arthritis visited our department with repetitive lower respiratory tract infections of Pseudomonas aeruginosa. Her chest CT showed diffuse panbronchiolitis-like pulmonary lesions, her blood examination revealed atypical lymphocytes, and she was serologically positive for anti-human T-lymphotrophic virus type 1 (HTLV-1) antibody. Her rheumatoid arthritis had been well-controlled after biological agent treatment followed by anti-inflammatory analgesic treatment. She received long-term low-dose macrolide therapy for four years. The Pseudomonas aeruginosa gradually became multi-antibiotic-resistant. Her lower respiratory infection gradually became uncontrollable, and her adult T cell leukemia (ATL) developed to the acute phase. Due to repetitive lower respiratory tract infections and respiratory failure, however, she could not receive any treatment for ATL, and she eventually died due to the progression of the disease. An autopsy revealed an invasion of abnormal lymphocytes in multiple organs, including the lungs, which indicated that the HTLV-1 infection and the progression of ATL were the dominant factors in this patient's clinical course. There have been no diffuse panbronchiolitis-like cases accompanied by rheumatoid arthritis and HTLV-1 infection so far. Because these diseases show similar clinical features, it is difficult to discriminate between them. There are presently no appropriate criteria for the proper time of treatment of patients with pulmonary lesion-associated ATL, but further research is expected to elucidate this matter.

The significance of oral streptococci in patients with pneumonia with risk factors for aspiration: the bacterial floral analysis of 16S ribosomal RNA gene using bronchoalveolar lavage fluid.

BACKGROUND: Aspiration pneumonia has been a growing interest in an aging population. Anaerobes are important pathogens, however, the etiology of aspiration pneumonia is not fully understood. In addition, the relationship between the patient clinical characteristics and the causative pathogens in pneumonia patients with aspiration risk factors are unclear. To evaluate the relationship between the patient clinical characteristics with risk factors for aspiration and bacterial flora in bronchoalveolar lavage fluid (BALF) in pneumonia patients, the bacterial floral analysis of 16S ribosomal RNA gene was applied in addition to cultivation methods in BALF samples. METHODS: From April 2010 to February 2014, BALF samples were obtained from the affected lesions of pneumonia via bronchoscopy, and were evaluated by the bacterial floral analysis of 16S rRNA gene in addition to cultivation methods in patients with community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP). Factors associated with aspiration risks in these patients were analyzed. RESULTS: A total of 177 (CAP 83, HCAP 94) patients were enrolled. According to the results of the bacterial floral analysis, detection rate of oral streptococci as the most detected bacterial phylotypes in BALF was significantly higher in patients with aspiration risks (31.0 %) than in patients without aspiration risks (14.7 %) (P = 0.009). In addition, the percentages of oral streptococci in each BALF sample were significantly higher in patients with aspiration risks (26.6 ± 32.0 %) than in patients without aspiration risks (13.8 ± 25.3 %) (P = 0.002). A multiple linear regression analysis showed that an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of ≥3, the presence of comorbidities, and a history of pneumonia within a previous year were significantly associated with a detection of oral streptococci in BALF. CONCLUSIONS: The bacterial floral analysis of 16S rRNA gene revealed that oral streptococci were mostly detected as the most detected bacterial phylotypes in BALF samples in CAP and HCAP patients with aspiration risks, especially in those with a poor ECOG-PS or a history of pneumonia.

[Factors Associated with Diagnostic Yield of Endobronchial Ultrasonography with a Guide Sheath for Peripheral Lung Cancer].

Endobronchial ultrasonography with a guide sheath (EBUS-GS) has recently been used for improved diagnostic yields for peripheral pulmonary lesions. This study retrospectively evaluated the factors related to the diagnostic yield of EBUS-GS for peripheral lung cancer. The medical records of 76 patients who had been diagnosed with lung cancer and had undergone bronchoscopy with EBUS-GS in our hospital between August 2014 and September 2015 were reviewed. The total diagnostic ratio of peripheral lung cancer was 71.1%. The following factors of the diagnostic yield were evaluated: location of pulmonary lesion; size; feature; bronchus sign; location of EBUS probe; EBUS detection; number of biopsies performed; procedure time; use of virtual bronchoscopic navigation; use of EBUS-guided transbronchial needle aspiration with EBUS-GS; CT slice thickness; operator's years of medical experience; and specialized training in bronchoscopy at the National Cancer Center. In all cases, lesion size ≧ 20 mm (80.8% vs. 50.0%, P = 0.006), EBUS probe location "within" (90.0% vs. 50.0%, P < 0.001), EBUS detection (80.7% vs. 28.6%, P < 0.001), number of biopsies ≧ 5 (78.0% vs. 47.1%, P = 0.013), and bronchoscopy training (81.6% vs. 60.5%, P = 0.043) significantly contributed to an increase in the diagnostic yield. Following a multivariate analysis, EBUS probe location "within" was found to be the most significant factor affecting the diagnostic yield (odds ratio 14.10, 95% CI 3.53-56.60, P < 0.001), and bronchoscopy training was the second most significant factor (odds ratio 6.93, 95% CI 1.86-25.80, P = 0.004). EBUS probe location "within" and bronchoscopy training are the most important factors for improved diagnostic yield by bronchoscopy with EBUS-GS for peripheral lung cancer.

The clinical features of respiratory infections caused by the Streptococcus anginosus group.

BACKGROUND: The Streptococcus anginosus group (SAG) play important roles in respiratory infections. It is ordinarily difficult to distinguish them from contaminations as the causative pathogens of respiratory infections because they are often cultured in respiratory specimens. Therefore, it is important to understand the clinical characteristics and laboratory findings of respiratory infections caused by the SAG members. The aim of this study is to clarify the role of the SAG bacteria in respiratory infections. METHODS: A total of 30 patients who were diagnosed with respiratory infections which were caused by the SAG bacteria between January 2005 and February 2015 were retrospectively evaluated. RESULTS: Respiratory infections caused by the SAG were mostly seen in male patients with comorbid diseases and were typically complicated with pleural effusion. Pleural effusion was observed in 22 (73.3%) patients. Empyema was observed in half of the 22 patients with pleural effusion. S. intermedius, S. constellatus and S. anginosus were detected in 16 (53.3 %), 11 (36.7 %) and 3 (10.0 %) patients, respectively. Six patients had mixed-infections. The duration from the onset of symptoms to the hospital visit was significantly longer in "lung abscess" patients than in "pneumonia" patients among the 24 patients with single infections, but not among the six patients with mixed-infection. The peripheral white blood cell counts of the "pneumonia" patients were higher than those of the "lung abscess" patients and S. intermedius was identified significantly more frequently in patients with pulmonary and pleural infections (pneumonia and lung abscess) than in patients with bacterial pleurisy only. In addition, the patients in whom S. intermedius was cultured were significantly older than those in whom S. constellatus was cultured. CONCLUSIONS: Respiratory infections caused by the SAG bacteria tended to be observed more frequently in male patients with comorbid diseases and to more frequently involve purulent formation. In addition, S. intermedius was mainly identified in elderly patients with having pulmonary infection complicated with pleural effusion, and the aspiration of oral secretions may be a risk factor in the formation of empyema thoracis associated with pneumonia due to S. intermedius.

In-hospital airborne tuberculous infection from a lesion of calcified pleural thickening during thoracic surgery in a patient with lung cancer.

A 75-year-old Japanese man underwent thoracic surgery to treat a large lung cancer lesion in the left upper lobe with calcified pleural thickening. Postoperatively, viable Mycobacterium tuberculosis was detected in the margin of the resected thickened calcified pleural lesion. Therefore, an infection control investigation of medical staff who had come in contact with the patient was conducted. Consequently, two of the 14 healthcare professionals who had been in the operating room were diagnosed with latent tuberculous infections. Therefore, strict precautions against airborne infections are required to prevent the in-hospital transmission of M. tuberculosis in such cases.