Clinical characteristics and outcomes of hypersensitivity pneumonitis in South Korea.

BACKGROUND: Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) that results from an immune-mediated reaction involving various antigens in susceptible individuals. However, the clinical characteristics and outcomes of HP in South Korea are not well understood. OBJECTIVES: This study was conducted to identify the clinical characteristics and outcomes of HP in South Korea. DESIGN: This is a retrospective observational study investigating patients with pathologically confirmed HP at our center, along with a comprehensive review of published HP cases in the Republic of Korea. METHODS: This retrospective study analyzed 43 patients with pathologically proven HP at a single tertiary hospital in Korea between 1996 and 2020. In addition, case reports of HP published in Korea were collected. The clinical characteristics, etiologies, treatment, and outcomes of patients from our center, as well as case reports, were reviewed. Patients from our hospital were divided into fibrotic and nonfibrotic subtypes according to the ATS/JRS/ALAT guidelines. RESULTS: Among 43 patients with biopsy-proven HP, 12 (27.9%) and 31 (72.1%) patients were classified into the fibrotic and nonfibrotic subtypes, respectively. The fibrotic HP group was older (64.6 ± 8.5 versus 55.2 ± 8.3, p = 0.002) with less frequent complaints of fever (0% versus 45.2%, p = 0.013) compared to the nonfibrotic HP group. The most common inciting antigen was household mold (21, 48.8%), followed by inorganic substances (6, 14.0%). Inciting antigens were not identified in eight (18.6%) patients. Treatment of corticosteroids was initiated in 34 (79.1%) patients. An analysis of 46 patients from Korea by literature review demonstrated that reported cases were relatively younger and drugs were the most common etiology compared to our cohort. CONCLUSION: The analysis of reported cases, as well as our cohort, showed that exposure history and clinical manifestations are heterogeneous for patients with HP in South Korea.

Nondiagnostic, radial-probe endobronchial ultrasound-guided biopsy for peripheral lung lesions: The added value of radiomics from ultrasound imaging for predicting malignancy.

OBJECTIVES: This study investigated whether radiomic features extracted from radial-probe endobronchial ultrasound (radial EBUS) images can assist in decision-making for subsequent clinical management in cases with indeterminate pathologic results. METHODS: A total of 494 patients who underwent radial EBUS biopsy for lung nodules between January 2017 and December 2018 were allocated to our training set. For the validation set, 229 patients with radial EBUS biopsy results from January 2019 to April 2020 were used. A multivariate logistic regression analysis was used for feature selection and prediction modeling. RESULTS: In the training set, 157 (67 benign and 90 malignant) of 212 patients pathologically diagnosed as indeterminate were analyzed. In the validation set, 213 patients were diagnosed as indeterminate, and 158 patients (63 benign and 95 malignant) were included in the analysis. The performance of the radiomics-added model, which considered satellite nodules, linear arc, shape, patency of vessels and bronchi, echogenicity, spiculation, C-reactive protein, and minimum histogram, was 0.929 for the training set and 0.877 for the validation set, whereas the performance of the model without radiomics was 0.910 and 0.891, respectively. CONCLUSION: Although the next diagnostic step for indeterminate lung biopsy results remains controversial, integrating various factors, including radiomic features from radial EBUS, might facilitate decision-making for subsequent clinical management.

Trends and factors associated with influenza vaccination in subjects with asthma: analysis of the Korea National Health and Nutrition Examination Survey between 2010 and 2019.

Background: Despite the importance of influenza vaccination, its rates in subjects with asthma are suboptimal, especially in the young population. Methods: Among 72,843 adults aged ⩾18 years from the Korea National Health and Nutrition Examination Survey conducted between 2010 and 2019, 1643 with asthma were included. The yearly trends and factors associated with influenza vaccination were analyzed in subjects with asthma. In addition, stratified analyses were performed by age group (<65 versus ⩾65 years). Results: During the study period, the overall influenza vaccination rate among subjects with asthma fluctuated from 51.0% to 64.3%, with a consistently higher vaccination rate in elderly subjects than in young subjects. Among young subjects with asthma, factors positively associated with influenza vaccination were female sex [adjusted odds ratio (aOR) = 1.66, 95% confidence interval (CI) = 1.11-2.49], current asthma being treated (aOR = 1.69, 95% CI = 1.14-2.50), history of pulmonary tuberculosis (aOR = 2.01, 95% CI = 1.04-3.87), and dyslipidemia (aOR = 1.86, 95% CI = 1.05-3.30). However, unmarried subjects showed an inverse relationship (aOR = 0.50, 95% CI = 0.34-0.75). In elderly subjects, unmarried status (aOR = 0.52, 95% CI = 0.29-0.94), being underweight (aOR = 0.29, 95% CI = 0.09-0.97), and having a low income (aOR = 0.42, 95% CI = 0.18-0.97) were factors negatively associated with influenza vaccination. Conclusion: In the last 10 years, influenza vaccination rates have still been insufficient in subjects with asthma, particularly in young subjects. Considering the factors that are influencing the vaccination rates of young subjects, public policies to increase influenza vaccination rates in subjects with asthma need to be established urgently.

Antibiotic Maintenance and Redevelopment of Nontuberculous Mycobacteria Pulmonary Disease after Treatment of Mycobacterium avium Complex Pulmonary Disease.

Limited data are available regarding the impact of the antibiotic maintenance period on the redevelopment of nontuberculous mycobacteria-pulmonary disease (NTM-PD) after microbiological cure of Mycobacterium avium complex (MAC)-PD. This retrospective study included 631 MAC-PD patients who achieved microbiological cure between 1994 and 2021. Data on the antibiotic maintenance period, defined as the time between culture conversion and treatment completion, were collected. Redevelopment, the subsequent diagnosis of NTM-PD regardless of causative organism after microbiological cure, was investigated. Factors associated with redevelopment were analyzed after adjusting for disease severity using the body mass index, age, cavity, erythrocyte sedimentation rate, and sex (BACES) scoring system. In total, 205 (33%) patients experienced redevelopment, with a median maintenance period after culture conversion of 15.0 months (interquartile range, 13.0 to 22.0 months). A greater proportion of patients with the nodular bronchiectatic form of MAC-PD (87% versus 80%, P = 0.033) and a longer maintenance period (median 15.0 versus 14.0 months, P < 0.001) were noted in the redevelopment group compared with the nonredevelopment group. The cumulative rate of redevelopment according to the maintenance period did not differ between the >12-month and ≤12-month groups in the total patient population or the subgroups sorted according to BACES severity. No association between a maintenance period >12 months and redevelopment was identified in multivariate models. Extending the antibiotic maintenance period more than 12 months did not reduce the redevelopment rate even with adjustment for disease severity, suggesting the need to further optimize the duration of the antibiotic maintenance period. IMPORTANCE Limited data are available regarding the impact of the antibiotic maintenance period on the redevelopment of Mycobacterium avium complex-pulmonary (MAC-PD) disease after microbiological cure. To improve treatment outcomes and reduce the recurrence rate, current guidelines recommend maintenance of antibiotics for a minimum of 12 months after achievement of negative culture conversion. However, the optimal duration of antibiotic therapy for MAC-PD is not currently known. Moreover, in real-world clinical practice, total antibiotic duration is mainly impacted by the length of the maintenance period; however, it is unknown whether extending the maintenance period is beneficial for preventing redevelopment of NTM-PD. Our study may help to address concerns regarding the antibiotic maintenance period after achievement of negative culture conversion in patients with MAC-PD.

Change in individual chronic obstructive pulmonary disease assessment test item scores after short-term bronchodilator therapy and its impact on exacerbation in treatment-naïve patients with chronic obstructive pulmonary disease.

Background: The chronic obstructive pulmonary disease (COPD) assessment test (CAT) measures the health status of patients with COPD. We aimed to investigate the change in individual CAT scores after short-term bronchodilator therapy among treatment-naïve patients with COPD. Methods: Data from 148 patients newly diagnosed with COPD between January 2016 and April 2020 were retrospectively analyzed. We compared the CAT score, modified Medical Research Council (mMRC) dyspnea grade, and forced expiratory volume in 1 s (FEV1) before and after short-term (6 ± 2 months) bronchodilator therapy. We analyzed the change trends using generalized estimating equations. Results: The mean patient age was 70.9 years, and 92.6% were male. The total CAT score did not significantly improve. However, among the CAT items, phlegm [adjusted difference: -0.22 (-0.48, -0.002)], chest tightness [-0.30 (-0.56, -0.05)], and breathlessness [-0.45 (-0.66, -0.23)] scores significantly improved after bronchodilator therapy. The patients were divided into two groups: CAT score improved (n = 69) and not improved group (n = 79). The development of moderate-to-severe exacerbations during follow-up was significantly lower (2.9% versus 17.7%, p = 0.004) in the CAT score improved group. Conclusion: The improvement in CAT items indicating respiratory symptoms was more evident than the CAT total score after short-term bronchodilator therapy. Despite the significant increase in FEV1 after bronchodilator therapy, fewer than half of the patients achieved meaningful improvement in CAT, and this group showed significantly lower development of exacerbation during follow-up.

Clinical Characteristics of COPD Patients According to COPD Assessment Test (CAT) Score Level: Cross-Sectional Study.

PURPOSE: The chronic obstructive pulmonary disease (COPD) assessment test (CAT) is widely used to assess the impact of COPD symptoms on health status. Whilst the CAT consists of eight different items, details on the distribution of each item are limited. This study aimed to investigate the distribution and clinical implication of each CAT item, stratified by CAT severity group, in stable COPD patients. PATIENTS AND METHODS: This was a cross-sectional study at a single referral hospital in South Korea. Spirometry confirmed COPD patients with CAT measured at the first clinical visit were retrospectively identified. Patients were categorized into three groups: low (0 ≤ CAT < 10), medium (10 ≤ CAT < 20), and high (20 ≤ CAT ≤ 40) impact group. For the purpose of this analysis, the first four items (cough, sputum, chest tightness, and dyspnea) and the remaining four items (activities, confidence, sleep and energy) were also grouped as "pulmonary" and "extra-pulmonary", respectively. RESULTS: A total of 815 patients were included, and mean (SD) forced expiratory volume in 1 s (FEV1) was 62.8 (17.4) % pred. Among them, 300 patients (36.8%) were in the high impact group and had a greater exacerbation history and lower lung function. The proportion of "extra-pulmonary" items score was greater in patients with higher total CAT scores, with the activity and confidence items showing higher scores. CONCLUSION: In our study, in addition to dyspnea, activity limitation is a particular problem in individual patients with higher CAT total scores, for which physicians need to pay more attention. Our study suggests that whilst CAT total score captures the overall impact of COPD, each item of the CAT contains potentially useful information in understanding the patient's symptom burden.

Predicting the Risk of Malignancy of Lung Nodules Diagnosed as Indeterminate on Radial Endobronchial Ultrasound-Guided Biopsy.

The next diagnostic step in cases of indeterminate radial probe endobronchial ultrasound (radial EBUS)-guided biopsy results remains uncertain. This study aimed to identify risk factors for malignancy based on clinical findings, chest computed tomography (CT), and radial EBUS images, and to estimate the risk of malignancy in lung nodules that showed indeterminate radial EBUS-guided biopsy results by constructing a nomogram. This retrospective study included 157 patients with indeterminate results on an initial radial EBUS biopsy performed at the Samsung Medical Center from January 2017 to December 2018, but with a definitive final diagnosis. Medical records, chest CT, radial EBUS images, and the final diagnoses were reviewed. Patients were randomly divided into training and validation sets. Factors related to malignancy were identified through logistic regression analysis, and a nomogram was constructed using the training set and subsequently applied to the validation set. Six factors in univariable and multivariable analyses, including upper lobe location, spiculation, satellite nodules, echogenicity, presence of dots or linear arcs, and patency of vessels and bronchi predicted malignancy. A nomogram was constructed based on these predictors. The area under the curve (AUC) value of the nomogram was 0.858 using the chest CT factors, which improved to 0.952 when radial EBUS factors were added. The calibration curve showed good agreement between the actual and nomogram-predicted malignancy outcomes. The utility of radial EBUS images for revealing risk factors of malignancy was confirmed. Furthermore, our nomogram was able to predict the probability of malignancy in lung nodules with indeterminate radial EBUS-guided biopsy results.

Tracheobronchopathia osteochondroplastica (TPO) associated with tracheobronchial amyloidosis (TBA).

Tracheobronchopathia osteochondroplastica (TPO) is an idiopathic disease involving the cartilage rings of the large airway, characterized by submucosal calcified nodules. Localized tracheobronchial amyloidosis (TBA) is another rare disease with localized amyloid deposits in the tracheobronchial tree. The two diseases rarely coincide, and only a few case reports and series have been reported. A patient with dyspnea was referred to our clinic for suspicion of TBA. Chest computed tomography (CT) scan showed marked thickening of the tracheobronchial wall with calcified endobronchial submucosal nodules. The nodules were resected with a Diode Laser under rigid bronchoscopy, and results from the biopsy showed both osteochondroid metaplasia on microscopy in Hematoxylin and Eosin staining and apple-green birefringence on polarized microscopy in Congo red staining. This is a rare case in which microscopic findings of both TPO and TBA were observed on one slide. These findings suggest that localized TBA could be a cause of TPO.

Tracheobronchopathia osteochondroplastica (TPO) associated with tracheobronchial amyloidosis (TBA).

Tracheobronchopathia osteochondroplastica (TPO) is an idiopathic disease involving the cartilage rings of the large airway, characterized by submucosal calcified nodules. Localized tracheobronchial amyloidosis (TBA) is another rare disease with localized amyloid deposits in the tracheobronchial tree. The two diseases rarely coincide, and only a few case reports and series have been reported. A patient with dyspnea was referred to our clinic for suspicion of TBA. Chest computed tomography (CT) scan showed marked thickening of the tracheobronchial wall with calcified endobronchial submucosal nodules. The nodules were resected with a Diode Laser under rigid bronchoscopy, and results from the biopsy showed both osteochondroid metaplasia on microscopy in Hematoxylin and Eosin staining and apple-green birefringence on polarized microscopy in Congo red staining. This is a rare case in which microscopic findings of both TPO and TBA were observed on one slide. These findings suggest that localized TBA could be a cause of TPO.

S-100-Negative malignant pulmonary granular cell tumor: A case report.

Malignant pulmonary granular cell tumor (GCT) is extremely rare and difficult to distinguish from benign GCT. Most GCTs are neural-type and express S-100. However, a small subset of tumors sub-classified as the non-neural type do not express S-100. We report a case of malignant non-neural-type GCT in the lungs. A 77-year-old woman felt chest discomfort and dyspnea in July 2019. She had never smoked and had no medical history other than hypertension and diabetes mellitus. She was initially evaluated at a local hospital. Flexible bronchoscopy showed total occlusion of the right main bronchus by a mass-like lesion. Biopsy of the mass lesion revealed chronic inflammation. The patient visited for re-evaluation in September 2019. Rigid bronchoscopy showed worsening of the total obstruction of the right main bronchus by a tumor mass, such that the carina was not visible. Additionally, endobronchial nodules were observed on the medial side of left main bronchus. The tumor masses of both main bronchi were removed by bronchoscopic intervention, but the right main bronchus was not opened. Biopsy revealed malignant GCT, favoring the non-neuronal type (S-100-negative). We report an extremely rare case of malignant pulmonary GCT negative for S-100 in immunohistochemistry. In this case, surgical resection was not possible because the tumor was diagnosed at a fairly advanced stage and had spread to involve the contralateral main bronchus. The patient chose to be treated at another hospital and was thereafter lost to follow-up.

Surgically intractable bronchopleural fistula treated with endobronchial valve insertion by isolating the tract with indigo carmine: A case report.

Bronchopleural fistula (BPF) is a communication between the pleural space and the bronchial tree. Herein, we report a patient with persistent air leak after necrotizing pneumonia, where tract of BPF was not apparent in computed tomography (CT). Despite control of infection, watchful observation, repetitive procedures, and surgery, air leak was not resolved. This led to consideration of the endobronchial valve (EBV) placement. After identifying the bronchial segment leading to the fistula with indigo carmine, precise occlusion of the lingular division of the left upper lobe (LUL) was performed using an EBV. Subsequently, the air leak was resolved. During 6 months of follow-up, neither recurrence of BPF nor any procedure-related complications were noted. We concluded that precise EBV placement by identifying bronchial segment leading to the BPF, could be an effective treatment for persistent air leak.