Relapsing bronchopneumonia due to community-associated methicillin-resistant Staphylococcus aureus: a case report.

BACKGROUND: The emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased the incidence of community-onset MRSA infection. Respiratory tract infections caused by MRSA has been noted for their severity; however, repeated relapses that require extended antibiotic therapy are rare. CASE PRESENTATION: We report a case of relapsing bronchopneumonia caused by CA-MRSA in a 56-year-old man. The patient responded to antibiotics, but repeatedly relapsed after stopping treatment. MRSA was consistently isolated from airway specimens during each relapse. Extended oral antibiotic treatment with trimethoprim/sulfamethoxazole (TMP/SMX) for 6 months achieved infection control. Whole-genome sequencing of the isolated strain revealed that the causative agent was sequence type (ST)1/staphylococcal cassette chromosome mec (SCCmec) type IVa, a clone that is rapidly increasing in Japan. DISCUSSION AND CONCLUSIONS: This patient had an unusual course of MRSA bronchopneumonia with repeated relapses. Although the choice of antibiotics for long-term use in MRSA respiratory tract infections has not been well established, TMP/SMX was effective and well tolerated for long-term therapy in this case. The clinical course of infections related to the rapid emerging clone, ST1/SCCmec type IVa warrants further attention.

Assessment of clinical relevance of antigen improves diagnostic accuracy of hypersensitivity pneumonitis.

BACKGROUND: Exposure assessment is integral to the diagnosis of hypersensitivity pneumonitis (HP). Although the clinical relevance of exposed antigens is essential for the assessment, many of the previous guidelines or reports have only evaluated simple exposure histories or immunological tests. To overcome this problem, the Exposure Assessment Form (EAF) was developed as an assessment tool for classifying the exposure grade from G0 to G4. The EAF was modified from the description in the Japanese clinical practice guide 2022 for HP published by the Japanese Respiratory Society. METHODS: One hundred and seventy-two consecutive patients with interstitial lung disease who underwent multidisciplinary discussion (MDD) at our hospital were retrospectively examined. We assessed whether the use of the EAF improved the diagnostic performance of the international guideline of HP. We also evaluated whether the exposure grade affected the prognosis of HP. RESULTS: Even when a HP diagnosis was made with a confidence of 70% or higher according to the international guideline, less than half of these cases resulted in a final diagnosis of HP when the exposure grades were lower than G3. When the result of the EAF was integrated into the exposure definition of the international guideline, the specificity of the diagnostic performance improved, while sensitivity was maintained. Furthermore, HP patients with an exposure grade of G3 or higher showed a tendency to take a longer time to initiate medication. CONCLUSIONS: This is the first study to evaluate the clinical relevance of possible antigens using the EAF. Assessing the exposure grade prevents overdiagnosis and improves the diagnostic performance of the international guideline.

A Case of Solitary Pure Ground-glass Opacity Suspected of Being the Initial Presentation of Nonfibrotic Hypersensitivity Pneumonitis.

We herein report a rare case of hypersensitivity pneumonitis (HP) that was initially demonstrated as solitary pure ground-glass opacity (GGO) on chest computed tomography (CT). A 51-year-old woman with a history of breast cancer underwent follow-up CT, which revealed solitary pure GGO. The patient developed exertional dyspnea after two years, and CT revealed diffuse centrilobular nodules in addition to GGO, which had increased in size. An antigen avoidance test was performed to diagnose HP, leading to the resolution of CT abnormalities, including the GGO. Our findings suggested that nonfibrotic HP can present as solitary pure GGO.

Deep convolutional neural network for differentiating between sarcoidosis and lymphoma based on [18F]FDG maximum-intensity projection images.

OBJECTIVES: To compare the [18F]FDG PET/CT findings of untreated sarcoidosis and malignant lymphoma (ML) and develop convolutional neural network (CNN) models to differentiate between these diseases using maximum intensity projection (MIP) [18F]FDG PET images. METHODS: We retrospectively collected data on consecutive patients newly diagnosed with sarcoidosis and ML who underwent [18F]FDG PET/CT before treatment. Two nuclear radiologists reviewed the images. CNN models were created using MIP PET images and evaluated with k-fold cross-validation. The points of interest were visualized using gradient-weighted class activation mapping (Grad-CAM). RESULTS: A total of 56 patients with sarcoidosis and 62 patients with ML were included. Patients with sarcoidosis had more prominent FDG accumulation in the mediastinal lymph nodes and lung lesions, while those with ML had more prominent accumulation in the cervical lymph nodes (all p < 0.001). For the mediastinal lymph nodes, sarcoidosis patients had significant FDG accumulation in the level 2, 4, 7, and 10 lymph nodes (all p < 0.01). Otherwise, the accumulation in ML patients tended to be in the level 1 lymph nodes (p = 0.08). The CNN model using frontal and lateral MIP images achieved an average accuracy of 0.890 (95% CI: 0.804-0.977), a sensitivity of 0.898 (95% CI: 0.782-1.000), a specificity of 0.907 (95% CI: 0.799-1.000), and an area under the curve of 0.963 (95% CI: 0.899-1.000). Grad-CAM showed that the model focused on the sites of abnormal FDG accumulation. CONCLUSIONS: CNN models based on differences in FDG accumulation sites archive high performance in differentiating between sarcoidosis and ML. CLINICAL RELEVANCE STATEMENT: We developed a CNN model using MIP images of [18F]FDG PET/CT to distinguish between sarcoidosis and malignant lymphoma. It achieved high performance and could be useful in diagnosing diseases with involvement across organs and lymph nodes. KEY POINTS: • There are differences in FDG distribution when comparing whole-body [18F]FDG PET/CT findings in patients with sarcoidosis and malignant lymphoma before treatment. • Convolutional neural networks, a type of deep learning technique, trained with maximum-intensity projection PET images from two angles showed high performance. • A deep learning model that utilizes differences in FDG distribution may be helpful in differentiating between diseases with lesions that are characteristically widespread among organs and lymph nodes.

Pulmonary Artery Aneurysm in a Patient with Nontuberculous Mycobacteria Infection.

Nontuberculous mycobacterial (NTM) infection sometimes leads to the development of pulmonary artery aneurysm (PAA), a rare but life-threatening complication. We herein report a 64-year-old woman with a history of NTM infection who presented with severe hemoptysis. Computed tomography revealed a ruptured PAA, which was treated successfully with pulmonary artery embolization. Subsequent right total pneumonectomy was performed to control infection. This case emphasizes the need to consider PAA in patients with NTM infection who present with hemoptysis. Early detection and appropriate management are critical for preventing this fatal complication.

Tolerability of sotorasib for KRAS positive lung adenocarcinoma patient with pre-existing interstitial pneumonia; A case report.

A 74-year-old man was referred to our hospital with an abnormal chest shadow. Computed tomography (CT) revealed a mass in the left upper lobe and interstitial pneumonia (IP). The patient underwent CT-guided needle biopsy and was diagnosed as lung adenocarcinoma with cT2aN1M1a Stage IVA (PUL). The patient was administered 6 cycles of CBDCA + nab-paclitaxel as first-line, 3 cycles of atezolizumab as second-line, and 8 cycles of S-1 as third-line treatment but finally showed tumor progression. Because comprehensive genome profiling test revealed KRAS G12C mutation, sotorasib was initiated as fourth-line treatment and showed tumor regression without exacerbation of pre-existing IP.

Understanding the process of people with hypersensitivity pneumonitis implementing continuous antigen avoidance and their affecting situations: A grounded theory study.

AIMS AND OBJECTIVES: To explore the process by which people with hypersensitivity pneumonitis implement continuous antigen avoidance, alongside the situations that influence this process. BACKGROUND: Antigen avoidance is the primary treatment for people with hypersensitivity pneumonitis. However, the best method to support antigen avoidance has not yet been established. DESIGN: The present qualitative study used a constructivist grounded theory approach. METHODS: The participants were inpatients or outpatients with hypersensitivity pneumonitis diagnosed at a Japanese urban university hospital. In parallel with semi-structured interviews and a medical record survey from 2016 to 2021, we conducted coding, categorising, writing memos, theoretical sampling and continuous comparisons of experiences from finding physical abnormalities to implementing antigen avoidance. The COREQ checklist was followed for reporting. RESULTS: Interpreting the experiences leading to the implementation of continuous antigen avoidance by 28 participants provided a process consisting of a core category: trying to maintain one's desired life under uncertain situations, and four phases: (1) searching for a convincing cause of the illness, (2) gradually understanding the disease, (3) realising the need for behaviour change and (4) seeking a good balance between behaviour change and one's desired life. The situations that influenced the process were also revealed. CONCLUSIONS: Being convinced of the cause of one's illness and realising its severity led to the participants' realisation of the need for a behavioural change to avoid antigens. The uncertainty of the cause of illness and measures taken, a lack of clear advice from healthcare providers and one's desired life influenced participants' implementation of continuous antigen avoidance. RELEVANCE TO CLINICAL PRACTICE: This study provides important insights regarding how healthcare providers should better understand and support people with hypersensitivity pneumonitis in avoiding antigens.

Association of SARS-CoV-2 RNA Copy Number with the COVID-19 Mortality Rate and Its Effect on the Predictive Performance of Mortality in Severe Cases.

Factors associated with mortality are important in the treatment of coronavirus disease 2019 (COVID-19). Polymerase chain reaction (PCR) is the gold standard for diagnosing COVID-19, which reflects the viral load in the upper respiratory tract. In total, 523 patients were enrolled in this study; of them, 441 and 75 patients underwent PCR testing of nasopharyngeal swabs and sputum samples, respectively, within 20 days from onset of COVID-19. We investigated the association between RNA copy number and the COVID-19 severity and mortality rate and its effect on the predictive performance for severity and mortality. RNA copy numbers in nasopharyngeal swabs were higher in the non-survivor group than in the survivor group. Multivariate logistic regression analysis identified that the high RNA copy number (≥9 log10 /swab) in nasopharyngeal swabs was a factor associated with mortality (odds ratio, 4.50; 95% confidence interval, 1.510-13.100; P = 0.008). Furthermore, adding RNA copy number (≥9 log10 /swab) in severe cases, adjusted by duration from onset to PCR, improved mortality predictive performance based on known factors. The RNA copy number is a factor associated with the mortality of patients with COVID-19 and can improve the predictive performance of mortality in severe cases.

Successful diagnosis of humidifier lung by individual provocation test to a responsible environment, a case report.

A 52-year-old woman presented with repeating episodes of pneumonia which spontaneously resolved after hospitalization. Hypersensitivity pneumonitis was suspected, but the causative antigen was not determined whether the parakeets she kept or the humidifier she owned was causative exposure. To identify which exposure is culprit, individual provocation test to a responsible environment was sequentially conducted. First, a home-returning provocation test to the parakeet was negative. Contrarily, the humidifier provocation test to her own humidifier was positive for symptoms, radiological changes, and inflammatory responses in blood test. Finally, she was diagnosed as having humidifier lung. When several antigens are suspected to be the causative agents for hypersensitivity pneumonitis, a step-by-step provocation tests is useful.

A phase II feasibility study of carboplatin and nab-paclitaxel for advanced non-small cell lung cancer patients with interstitial lung disease (YLOG0114).

BACKGROUND: A standard treatment regimen for advanced non-small cell lung cancer (NSCLC) patients with interstitial lung disease (ILD) has not been established since most clinical trials exclude such patients because of the high risk of acute exacerbation of ILD. This study aimed to prospectively investigate the efficacy and safety of carboplatin and nab-paclitaxel as a first-line regimen for NSCLC patients with ILD. METHODS: The enrolled patients had treatment-naïve advanced NSCLC with ILD. The patients received 4-6 cycles of carboplatin (area under the curve = 5) on day 1 and nab-paclitaxel 100 mg/m2 on days 1, 8, and 15 every 4 weeks. The primary endpoint was the completion rate of four or more cycles. Secondary endpoints included toxicity, overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). RESULTS: Twenty-five patients were enrolled in this study. Nine patients had adenocarcinoma, 11 had squamous cell carcinoma, one had large cell carcinoma, and four had NSCLC, not otherwise specified. The completion rate of ≥4 cycles was 76% (95% confidence interval: 56.2%-88.8%), which met the primary endpoint. The ORR and DCR were 44% and 88%, respectively. The median PFS and OS were 5.8 months and 15.8 months, respectively. Three patients experienced grade ≥2 pneumonitis, and one patient met the acute exacerbation criteria. CONCLUSION: The 4-week modified regimen of carboplatin and nab-paclitaxel showed tolerable toxicity with favorable efficacy in NSCLC patients with ILD. This regimen may be an effective treatment option for patients in real clinical settings.

Common idiopathic pulmonary fibrosis risk variants are associated with hypersensitivity pneumonitis.

A subset of patients with hypersensitivity pneumonitis (HP) develop lung fibrosis that is clinically similar to idiopathic pulmonary fibrosis (IPF). To address the aetiological determinants of fibrotic HP, we investigated whether the common IPF genetic risk variants were also relevant in study subjects with fibrotic HP. Our findings indicate that common genetic variants in TERC, DSP, MUC5B and IVD were significantly associated with fibrotic HP. These findings provide support for a shared etiology and pathogenesis between fibrotic HP and IPF.

Propionibacterium acnes-Derived Circulating Immune Complexes in Sarcoidosis Patients.

Propionibacterium acnes is a potential etiologic agent of sarcoidosis and a dysregulated immune response to the commensal bacterium is suspected to cause granuloma formation. P. acnes-derived insoluble immune complexes were recently demonstrated in sinus macrophages of sarcoidosis lymph nodes, suggesting local proliferation of the bacterium in affected organs. In the present study, we developed a method for detecting P. acnes-derived immune complexes in human blood by measuring the concentration of P. acnes-specific lipoteichoic acid (PLTA) detectable after an antigen retrieval pretreatment of plasma samples. Before pretreatment, anti-PLTA antibody was detected and PLTA could not be detected, in all plasma samples from 51 sarcoidosis patients and 35 healthy volunteers. After pretreatment, however, a significant level of PLTA (>105 ng/mL) was detected in 33 (65%) sarcoidosis patients and 5 (14%) control subjects, with 86% specificity and 65% sensitivity for sarcoidosis. In both groups, plasma anti-PLTA antibody titers did not differ between samples with and without detection of PLTA. PLTA levels were abnormally increased (>202 ng/mL) in 21 (41%) sarcoidosis patients. These findings suggest that P. acnes-derived circulating immune complexes present in human blood are abnormally increased in many sarcoidosis patients, presumably due to local proliferation of the bacterium in the affected organs.

Chronic Hypersensitivity Pneumonitis, an Interstitial Lung Disease with Distinct Molecular Signatures.

Rationale: Chronic hypersensitivity pneumonitis (CHP) is caused by an immune response to antigen inhalation and is characterized by variable histopathological and clinical features. A subset of subjects with CHP have usual interstitial pneumonia and appear to be clinically similar to subjects with idiopathic pulmonary fibrosis (IPF).Objectives: To determine the common and unique molecular features of CHP and IPF.Methods: Transcriptome analysis of lung samples from CHP (n = 82), IPF (n = 103), and unaffected controls (n = 103) was conducted. Differential gene expression was determined adjusting for sex, race, age, and smoking history and using false discovery rate to control for multiple comparisons.Measurements and Main Results: When compared with controls, we identified 413 upregulated and 317 downregulated genes in CHP and 861 upregulated and 322 downregulated genes in IPF. Concordantly upregulated or downregulated genes in CHP and IPF were related to collagen catabolic processes and epithelial development, whereas genes specific to CHP (differentially expressed in CHP when compared with control and not differentially expressed in IPF) were related to chemokine-mediated signaling and immune responsiveness. Using weighted gene coexpression network analysis, we found that among subjects with CHP, genes involved in adaptive immunity or epithelial cell development were associated with improved or reduced lung function, respectively, and that MUC5B expression was associated with epithelial cell development. MUC5B expression was also associated with lung fibrosis and honeycombing.Conclusions: Gene expression analysis of CHP and IPF identified signatures common to CHP and IPF, as well as genes uniquely expressed in CHP. Select modules of gene expression are characterized by distinct clinical and pathological features of CHP.

Periostin as a predictor of prognosis in chronic bird-related hypersensitivity pneumonitis.

BACKGROUND: Periostin is an established biomarker of Th2 immune response and fibrogenesis. Recent research has indicated that periostin plays an important role in the pathogenesis of idiopathic interstitial pneumonias. To clarify the relationship between periostin and pathogenesis in chronic bird-related hypersensitivity pneumonitis (HP) and to reveal the usefulness of serum periostin levels in diagnosing and managing chronic bird-related HP. METHODS: We measured serum periostin in 63 patients with chronic bird-related HP, 13 patients with idiopathic pulmonary fibrosis, and 113 healthy volunteers. We investigated the relationship between serum periostin and clinical parameters, and evaluated if the baseline serum periostin could predict the prognosis. RESULTS: Serum periostin was significantly higher in patients with chronic bird-related HP compared to the healthy volunteers. In chronic bird-related HP, serum periostin had significant positive correlations with serum KL-6 levels, the CD4/CD8 ratio in bronchoalveolar lavage fluid, and fibrosis score on HRCT, and a significant negative correlation with the diffusing capacity of the lungs for carbon monoxide. Chronic bird-related HP patients with serum periostin levels exceeding ≥92.5 ng/mL and ≥89.5 ng/mL had a significantly worse prognosis and significantly higher frequency of acute exacerbation, respectively. Higher serum periostin (92.5 ng/mL or higher; binary response for serum periostin) was an independent prognostic factor in multivariate analysis. CONCLUSIONS: Serum periostin may reflect the extent of lung fibrosis and play an important role in pathogenesis of chronic bird-related HP. Elevated serum periostin could be a predictor of prognosis in patients with chronic bird-related HP.

[A Case of Pulmonary Enteric Adenocarcinoma with Soleus Muscle Metastasis].

Pulmonary enteric adenocarcinoma is a unique pulmonary adenocarcinoma subtype and has histopathological findings that are similar to those of colorectal adenocarcinoma. A man in his 50s visited our hospital because of discomfort in his right lower leg for the last 9 months. Imaging studies revealed a mass in his right soleus muscle, and needle biopsy was performed. Histological findings revealed adenocarcinoma, and immunohistochemical staining showed that the tumor cells were positive for CK20 and CDX-2. The tumor was first suspected to be metastasis of gastrointestinal malignant tumors. FDG-PET/CT showed increased FDG uptake in the right soleus muscle mass and presented with increased FDG uptake in a right upper lobe mass and right mediastinum lymphadenopathy. There were no findings in other organs. Scraping cytology of a transbronchial biopsy indicated adenocarcinoma. Upper and lower gastrointestinal endoscopy showed no findings of malignancy. He was finally diagnosed with pulmonary enteric adenocarcinoma(cT3N2M1b, Stage ⅣA). Treatment with cisplatin(CDDP), pemetrexed( PEM), and bevacizumab(BEV) was initiated. After 4 courses of the regimen, the tumor was partially reduced, and the patient showed stable disease(SD).

Acute inflammatory and immunologic responses against antigen in chronic bird-related hypersensitivity pneumonitis.

BACKGROUND: Hypersensitivity pneumonitis (HP) is an immune-mediated lung disease induced by the inhalation of a wide variety of antigens and a persistent antigen exposure induces inevitably pulmonary fibrosis in chronic HP. Although neutrophils, Th1 and Th17 cells contribute to lung inflammation in acute phase of HP, there is no clear explanation as to how the immunological reaction occurs just after the inhalation of causative antigens in the chronic phase of HP. METHODS: We examined the inflammatory and immunologic profiles before and after the inhalation provocation test (IPT) in serum and bronchoalveolar lavage fluid (BALF) from patients with chronic bird-related HP (BRHP) and other interstitial lung diseases (ILDs). We analyzed BALF samples from 39 patients (19 BRHP and 20 other ILDs) and serum samples from 25 consecutive patients (20 BRHP and 5 other ILDs) who underwent the IPT. RESULTS: A significant increase of neutrophils was observed in the BALF from the BRHP patients following the IPT. Neutrophil chemoattractants, namely, granulocyte colony-stimulating factor, IL-6, IL-8, IL-17, and CXCL2 significantly increased in both the serum and BALF of the BRHP patients after the IPT. Serum IFN-γ and CXCL10, cytokines/chemokines that contributed to Th1 inflammation, were also significantly increased in BRHP following the IPT. CONCLUSIONS: This study demonstrated the exposure to the causative antigen provoked acute neutrophilic and Th1 immunologic responses similar to acute HP even in the chronic phase of HP.

Development of mediastinal adenitis six weeks after endobronchial ultrasound-guided transbronchial needle aspiration.

A 60-year-old man visited our hospital for further examination of an abnormal chest radiograph. Computed tomography (CT) images revealed enlarged mediastinal lymph nodes and multiple pulmonary nodules. Further evaluation by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was performed and he was diagnosed with sarcoidosis. Six weeks after EBUS-TBNA, he presented to the emergency department with a high-grade fever. CT scan revealed an enlarged mediastinal lymph node. He was diagnosed with mediastinal adenitis and treated successfully with antibiotics. EBUS-TBNA is a highly accurate diagnostic tool, but clinicians should be aware of mediastinal infectious complication that could be asymptomatic for long period of time.

Identification of apolipoprotein A-I in BALF as a biomarker of sarcoidosis.

Background: Sarcoidosis goes into remission in two-thirds of patients with sarcoidosis, but about 20 % of patients develop pulmonary fibrosis. The mechanisms of pulmonary fibrosis in sarcoidosis and differences in pathogenesis between clinical stages are still unclear. Objectives: The aim of this study was investigating proteins associated with clinical stages by comparing bronchoalveolar lavage fluid (BALF) protein between stage I and stage IV using proteome analysis. Methods: Proteomic differences in BALF were compared between stage I and stage IV by examining BALF from 8 stage I patients and 5 stage IV patients by two-dimensional gel electrophoresis and mass spectrometry. Results: In individual comparisons of BALF samples, the levels of apolipoprotein (Apo) A-I fragment, fibrinogen γ chain, calcyphosine, complement C3, and surfactant protein A were significantly higher in stage I than in stage IV. In contrast, none of the proteins examined significantly higher in stage IV than in stage I. To confirm the results of Apo A-I in the BALF proteome, we performed enzyme-linked immunosorbent assay (ELISA) in a larger group. The concentration of BALF Apo A-I was significantly higher in stage I patients than in stage IV patients (0.70 [0.13-0.89] vs. 0.15 [0.08-0.21] ng/µg protein, p=0.003). Conclusion: The involvement of BALF Apo A-I in sarcoidosis may differ between stage I and stage IV. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 5-15).

Pirfenidone in chronic hypersensitivity pneumonitis: a real-life experience.

Background: Pirfenidone is an antifibrotic drug used for the treatment of idiopathic pulmonary fibrosis. Objectives: The aim of this study was to evaluate the efficacy of pirfenidone in patients with chronic hypersensitivity pneumonitis (HP). Methods: Twenty-three patients with chronic HP treated with pirfenidone were enrolled in this study based on a retrospective medical record review. Results: The change in vital capacity (VC) in the 6 months after the start of treatment (-152±56.1 ml) was significantly improved compared with that in the 6 months before treatment (-292±77.8 ml, p=0.047). No patients discontinued the treatment with adverse events. Conclusions: These results demonstrate that pirfenidone may reduce the decline of VC in patients with chronic HP without eliciting significant adverse events. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 139-142).