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.

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.

MuLBSTA score is a useful tool for predicting COVID-19 disease behavior.

BACKGROUND: The prediction of COVID-19 disease behavior in the early phase of infection is challenging but urgently needed. MuLBSTA score is a scoring system that predicts the mortality of viral pneumonia induced by a variety of viruses, including coronavirus, but the scoring system has not been verified in novel coronavirus pneumonia. The aim of this study was to validate this scoring system for estimating the risk of disease worsening in patients with COVID-19. METHODS: This study included the patients who were treated between April 1 st and March 13 th , 2020. The patients were classified into mild, moderate, and severe groups according to the extent of respiratory failure. MuLBSTA score was applied to estimate the risk of disease worsening in each severity group and we validated the utility of the scoring system. RESULTS: A total of 72 patients were analyzed. Among the 46 patients with mild disease, 17 showed disease progression to moderate or severe disease after admission. The model showed a sensitivity of 100% and a specificity of only 34.5% with a cut-off value of 5 points. Among the 55 patients with mild or moderate disease, 6 deteriorated to severe disease, and the model showed a sensitivity of 83.3% and a specificity of 71.4% with a cut-off value of 11 points. CONCLUSIONS: This study showed that MuLBSTA score is a potentially useful tool for predicting COVID-19 disease behavior. This scoring system may be used as one of the criteria to identify high-risk patients worsening to life-threatening status.

Predictors associated with clinical improvement of SARS-CoV-2 pneumonia.

BACKGROUND: There are few agents that have been proven effective for COVID-19. Predicting clinical improvement as well as mortality or severity is very important. OBJECTIVES: This study aimed to investigate the factors associated with the clinical improvement of COVID-19. METHODS: Overall, 74 patients receiving treatment for COVID-19 at Tokyo Medical and Dental University Hospital from April 6th to May 15th, 2020 were included in this study. Clinical improvement was evaluated, which defined as the decline of two levels on a six-point ordinal scale of clinical status or discharge alive from the hospital within 28 days after admission. The clinical courses were particularly investigated and the factors related to time to clinical improvement were analyzed with the log-rank test and the Cox proportional hazard model. RESULTS: Forty-nine patients required oxygen support during hospitalization, 22 patients required invasive mechanical ventilation, and 5 patients required extracorporeal membrane oxygenation. A total of 83% of cases reached clinical improvement. Longer period of time from onset to admission (≥10 days) (HR, 1.057; 95% CI, 1.002-1.114), no hypertension (HR, 2.077; 95% CI, 1.006-4.287), and low D-dimer levels (<1 µg/ml) (HR, 2.372; 95% CI, 1.229-4.576) were confirmed to be significant predictive factors for time to clinical improvement. Furthermore, a lower SARS-CoV-2 RNA copy number was also a predictive factor for clinical improvement. CONCLUSIONS: Several predictors for the clinical improvement of COVID-19 pneumonia were identified. These results may be important for the management of COVID-19 pneumonia.

Basophils trigger emphysema development in a murine model of COPD through IL-4-mediated generation of MMP-12-producing macrophages.

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. It has generally been considered a non-Th2-type lung disorder, characterized by progressive airflow limitation with inflammation and emphysema, but its cellular and molecular mechanism remains ill defined, compared with that of asthma characterized by reversible airway obstruction. Here we show a previously unappreciated role for basophils at the initiation phase of emphysema formation in an elastase-induced murine model of COPD in that basophils represent less than 1% of lung-infiltrating cells. Intranasal elastase instillation elicited the recruitment of monocytes to the lung, followed by differentiation into interstitial macrophages (IMs) but rarely alveolar macrophages (AMs). Matrix metalloproteinase-12 (MMP-12) contributing to emphysema formation was highly expressed by IMs rather than AMs, in contrast to the prevailing assumption. Experiments using a series of genetically engineered mice suggested that basophil-derived IL-4, a Th2 cytokine, acted on lung-infiltrating monocytes to promote their differentiation into MMP-12-producing IMs that resulted in the destruction of alveolar walls and led to emphysema development. Indeed, mice deficient for IL-4 only in basophils failed to generate pathogenic MMP-12-producing IMs and hence develop emphysema. Thus, the basophil-derived IL-4/monocyte-derived IM/MMP-12 axis plays a crucial role in emphysema formation and therefore may be a potential target to slow down emphysema progression at the initiation phase of COPD.

The utility of ground-glass attenuation score for anticancer treatment-related acute exacerbation of interstitial lung disease among lung cancer patients with interstitial lung disease.

BACKGROUND: Acute exacerbation (AE) of interstitial lung disease (ILD) is a fatal adverse event in the treatment of lung cancer patients with ILD. The value of pre-treatment radiological findings obtained by high-resolution computed tomography for the detection of anticancer treatment-related AE of ILD has not been established. METHODS: Two medical record-based retrospective studies were performed. The chemotherapy cohort included 105 lung cancer patients with ILD who received chemotherapy at Tokyo Medical and Dental University between October 2008 and December 2017. The immune checkpoint inhibitor (ICI) cohort included 48 advanced non-small cell lung cancer patients with ILD treated with ICIs at nine institutions between January 2016 and September 2018. Variables were compared between AE-positive and -negative groups. Candidate variables were analyzed by multivariate logistic regression. A P value < 0.05 was considered statistically significant. RESULTS: Anticancer treatment-related AE of ILD occurred in 12 patients (11.4%) in the chemotherapy cohort and seven patients (14.5%) in the ICI cohort. In the multivariate logistic regression analysis, ground-glass attenuation (GGA) score was the only factor significantly associated with the development of AE of ILD in both cohorts (P = 0.037 and 0.01 in the chemotherapy and ICI cohorts, respectively). CONCLUSION: Evaluation of GGA may help predict anticancer treatment-related AE of ILD.

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.

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).

[A CASE OF ACUTE EXACERBATION OF CHRONIC BIRDRELATED HYPERSENSITIVITY PNEUMONITIS WITH A REMARKABLE ELEVATION OF ENVIRONMENTAL AVIAN ANTIGEN LEVELS].

A man in his 60's with interstitial pneumonitis who was previously admitted to another hospital was transferred to our hospital for further investigations 6 years prior to an acute exacerbation. Given his history of avian contact, the presence of antibodies specific to avian antigen, and a positive result of the inhalation provocation test using pigeon dropping extracts, he was diagnosed with bird-related hypersensitivity pneumonitis (BRHP). As such, we instructed the patient to avoid exposure to avian antigen, and regularly measured the level of avian antigen in dust samples collected from his household environment. Despite avoiding the stimulus, corticosteroids and immunosuppressants were needed in view of progression of dyspnea after approximately five to six years. Four months after immunosuppressant therapy began, the patient suffered an acute exacerbation of BRHP and died. At this time, we found that the level of avian antigen was much higher than baseline. We suggest that exposure to high level of avian antigen is one cause of an acute exacerbation of BRHP.

Histological variability and consequences in chronic bird-related hypersensitivity pneumonitis.

BACKGROUND AND OBJECTIVE: Lobar and temporal histological variability in chronic bird-related hypersensitivity pneumonitis (BRHP) has not been clearly elucidated. This study was designed to evaluate the spatio-temporal histopathological variability in chronic BRHP. METHODS: Fifty-two patients with chronic BRHP who underwent a surgical lung biopsy (SLB) between 1992 and 2008 were evaluated. The histopathological characteristics of the lung biopsy specimens were classified by the 2002 American Thoracic Society/European Respiratory Society (ATS/ERS) consensus classification of idiopathic interstitial pneumonias (IIPs). Autopsy specimens from seven patients were also evaluated to examine the serial changes from SLB to autopsy. RESULTS: In a study of lobar histological variability based on the findings of SLB, 7 patients were diagnosed with cellular nonspecific interstitial pneumonia (NSIP) pattern, 16 with fibrotic NSIP pattern, 20 with fibrotic NSIP pattern and usual interstitial pneumonia (UIP) (discordant UIP) pattern and 9 with UIP (concordant UIP) pattern. In a study of sequential changes, specimens of SLBs with fibrotic NSIP pattern changed to a bronchiolocentric interstitial pneumonia (BIP) pattern or UIP pattern. CONCLUSION: Interlobar and intralobar histological variability is present in chronic BRHP. In several patients with chronic BRHP, a fibrotic NSIP pattern may be an early lesion that progresses to a UIP pattern.

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.

Validation of a computed tomography diagnostic model for differentiating fibrotic hypersensitivity pneumonitis from idiopathic pulmonary fibrosis.

BACKGROUND: The diagnosis of fibrotic hypersensitivity pneumonitis (fHP) from other interstitial lung diseases, particularly idiopathic pulmonary fibrosis (IPF), is often difficult. This study aimed to examine computed tomography (CT) findings that were useful for differentiating between fHP and IPF and to develop and validate a radiological diagnostic model. METHODS: In this study, 246 patients (fHP, n = 104; IPF, n = 142) from two institutions were included and randomly divided into the test (n = 164) and validation (n = 82) groups (at a 2:1 ratio). Three radiologists evaluated CT findings, such as pulmonary fibrosis, small airway disease, and predominant distribution, and compared them between fHP and IPF using binomial logistic regression and multivariate analysis. A prognostic model was developed from the test group and validated with the validation group. RESULTS: Ground-glass opacity (GGO) with traction bronchiectasis (TB), honeycombing, hypoattenuation area, three-density pattern, diffuse craniocaudal distribution, peribronchovascular opacities in the upper lung, and random distribution were more common in fHP than in IPF. In multivariate analysis, GGO with TB, peribronchovascular opacities in the upper lung, and random distribution were significant features. The area under the curve of the fHP diagnostic model with the three aforementioned CT features was 0.733 (95% confidence interval [CI], 0.655-0.811, p < 0.001) in the test group and 0.630 (95% CI, 0.504-0.755, p < 0.047) in the validation group. CONCLUSION: GGO with TB, peribronchovascular opacities in the upper lung, and random distribution were important CT features for differentiating fHP from IPF.

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.

Pulmonary function and chest CT abnormalities 3 months after discharge from COVID-19, 2020-2021: A nation-wide multicenter prospective cohort study from the Japanese respiratory society.

BACKGROUND: No comprehensive analysis of the pulmonary sequelae of coronavirus disease 2019 (COVID-19) in Japan based on respiratory function tests and chest computed tomography (CT) has been reported. We evaluated post-COVID-19 conditions, especially focusing on pulmonary sequelae assessed by pulmonary function tests and chest CT. METHODS: For this prospective cohort study, we enrolled 1069 patients who presented pneumonia at the time of admission in 55 hospitals from February 2020 to September 2021. Disease severity was classified as moderateⅠ, moderate II, and severe, defined primarily according to the degree of respiratory failure. The data on post-COVID-19 conditions over 12 months, pulmonary function, and chest CT findings at 3 months were evaluated in this study. Additionally, the impact of COVID-19 severity on pulmonary sequelae, such as impaired diffusion capacity, restrictive pattern, and CT abnormalities, was also evaluated. RESULTS: The most frequently reported post-COVID-19 conditions at 3 months after COVID-19 were muscle weakness, dyspnea, and fatigue (48.4%, 29.0%, and 24.7%, respectively). The frequency of symptoms gradually decreased over subsequent months. In pulmonary function tests at 3 months, the incidence of impaired diffusion capacity and restrictive pattern increased depending on disease severity. There also were differences in the presence of chest CT abnormalities at the 3 months, which was markedly correlated with the severity. CONCLUSION: We reported a comprehensive analysis of post-COVID-19 condition, pulmonary function, and chest CT abnormalities in Japanese patients with COVID-19. The findings of this study will serve as valuable reference data for future post-COVID-19 condition research in Japan.

Higher serum CCL17 may be a promising predictor of acute exacerbations in chronic hypersensitivity pneumonitis.

BACKGROUND: Recent research has suggested that the Th1 and Th2 chemokine/cytokine axis contributes to the development of chronic hypersensitivity pneumonitis (HP). Acute exacerbations (AE) are significant factors in the prognosis of chronic HP. Little is known, however, about these biomarkers in association with AE in chronic HP patients. METHODS: Fifty-six patients with chronic HP were evaluated, including 14 patients during episodes of AE. Th1 mediators (C-X-C chemokine ligand [CXCL]10 and interferon [IFN]-γ), Th2 mediators (C-C chemokine ligand [CCL]17, interleukin-4, and interleukin-13), and pro-fibrotic mediator (transforming growth factor [TGF]-ß) were measured to evaluate the mediators as predictors of AE. C-C chemokine receptor (CCR)4 (receptor for CCL17)-positive lymphocytes were quantified in lung specimens. RESULTS: Serum CCL17 levels at baseline independently predicted the first episode of AE (HR, 72.0; 95% CI, 5.03-1030.23; p = 0.002). AE was significantly more frequent in the higher-CCL17 group (≥285 pg/ml) than in the lower-CCL17 group (<285 pg/ml) (log-rank test, p = 0.0006; 1-year incidence: higher CCL17 vs. lower CCL17, 14.3% vs. 0.0%). Serum CCL17 levels and CCR4-positive cells during episodes of AE were increased from the baseline (p = 0.01 and 0.031). CONCLUSIONS: Higher serum concentrations of CCL17 at baseline may be predictive of AE in patients with chronic HP, and CCL17 may contribute to the pathology of AE by inducing the accumulation of CCR4-positive lymphocytes in the lungs.

Database analysis of hypersensitivity pneumonitis in Japan.

BACKGROUND: Three epidemiological small-scale studies on hypersensitivity pneumonitis (HP) have been performed in Japan to date. Herein, we aimed to clarify the clinical characteristics of various types of HP diseases using a large nationwide database in Japan. METHODS: We used the Japanese Diagnostic Procedure Combination database that includes data from 1,031 participant hospitals. Patients with HP from 2011 to 2017 were identified using International Classification of Diseases 10th Revision codes. We analyzed patient characteristics, the yearly transition of the number of HP cases, rate per one million hospitalizations, geographical distribution, seasonality, and risk factors for in-hospital mortality. RESULTS: In total, 3,634 patients with HP were identified, including summer-type HP (SHP) (n = 490), bird fancier's lung (BFL) (n = 199), ventilation pneumonitis (n = 106), farmer's lung (n = 48), and unspecified HP (n = 2761). The length of hospital stay was significantly longer in patients with BFL (19 days) than in patients with SHP (15 days). SHP was more prevalent in the southwestern region of Japan, and hospitalization occurred mainly in summer (37.8%) and fall (37.3%). Ventilation pneumonitis was predominant in winter (28.6%) and spring (38.7%). In-hospital mortality was significantly associated with old age (p < 0.001), low body mass index (p = 0.016), severe dyspnea (p < 0.001), and BFL diagnosis on admission (p = 0.031). CONCLUSIONS: This study revealed the clinical characteristics of SHP and BFL, including the frequency of causative antigens, geographical distribution, seasonality, and risk factors for mortality, which may help in diagnosing HP and identifying causative antigens.

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.

COVID-19 Pneumonia Followed by Anti-signal Recognition Particle Antibody-positive Fibrosing Interstitial Lung Disease.

Coronavirus disease 2019 (COVID-19) pneumonia is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is frequently accompanied by various sequelae. Interstitial lung diseases (ILDs) are observed in COVID-19 pneumonia patients after recovery, probably due to persistent inflammation in the lungs. We herein report a case of ILD with anti-signal recognition particle antibodies following severe COVID-19 pneumonia. The patient was diagnosed with ILD three months after COVID-19 pneumonia. Although the exact mechanism is unknown, the autoantibody-induced immune response might have been the pulmonary fibrosis trigger in this patient.