Allergen Sensitization and Its Association With Allergic Diseases in the Korean Population: Results From the 2019 Korea National Health and Nutrition Examination Survey.

PURPOSE: Allergen exposure is the most potent factor in allergen sensitization, which affects the exacerbation and severity of allergic diseases. Due to industrialization and climate change, the pattern of allergen sensitization has changed over time, and the incidence of allergic diseases has also increased. This study investigated the status of allergen sensitization in the Korean population and its effects on allergic diseases. METHODS: A total of 2,386 participants aged ≥ 10 years, who underwent 7 specific immunoglobulin E tests for aeroallergens (Dermatophagoides farinae [Der f], dog dander, cat epithelium, birch, oak, Japanese hop, and ragweed), were selected among the participants of the 2019 Korean National Health and Nutrition Examination Survey. We compared the demographic characteristics, combined allergic diseases, and sinusitis symptoms between the atopic and non-atopic groups. RESULTS: The prevalence of allergen sensitization in the general Korean population was 45%, and Der f was the most frequent cause of sensitization (39.9%). The prevalence of sensitization to indoor allergens was highest among teenagers and those belonging to the 20- to 29-year age group (P < 0.001). In contrast, there was a high prevalence of sensitization to outdoor allergens among individuals belonging to the age group of 60-69 years. The prevalence of atopic dermatitis (odds ratio [OR], 2.559; 95% confidence interval [CI], 1.689-3.878), allergic rhinitis (OR, 3.075; 95% CI, 2.426-3.897), and otitis media (OR, 1.481; 95% CI, 1.092-2.007) significantly increased by allergen sensitization. Patients with allergen sensitization were more likely to experience the symptoms of rhinitis and sinusitis. CONCLUSIONS: The study findings confirmed that allergen sensitization occurs in approximately half of the general Korean population and affects the prevalence and symptoms of allergic diseases. This suggests that active allergy tests and diagnosis of allergic diseases are necessary in Koreans.

Eosinophilia Is a Favorable Marker for Pneumonia in Chronic Obstructive Pulmonary Disease.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) expressing eosinophilia experience slightly fewer episodes of community-acquired pneumonia (CAP), than those without eosinophilia. However, the severity and burden of hospitalized pneumonia patients with COPD involving eosinophilia have not been assessed. METHODS: We evaluated the differences in clinical characteristics between patients with CAP and COPD with or without eosinophilia by a post hoc analysis of a prospective, multi-center, cohort study data. RESULTS: Of 349 CAP patients with COPD, 45 (12.9%) had eosinophilia (blood eosinophil ≥300 cells/µL). Patients with eosinophilia had a lower sputum culture percentile (8.1% vs. 23.4%, p<0.05), a lower percentile of neutrophils (70.3% vs. 80.2%, p<0.05), reduced C-reactive protein levels (30.6 mg/L vs. 86.6 mg/L, p<0.05), and a lower pneumonia severity index score (82.5 vs. 90.0, p<0.05), than those without eosinophilia. The duration of antibiotic treatment (8.0 days vs. 10.0 days, p<0.05) and hospitalization (7.0 days vs. 9.0 days, p<0.05) were shorter in eosinophilic patients. The cost of medical care per day (256.4 US$ vs. 291.0 US$, p<0.05), cost for the medication (276.4 US$ vs. 349.9 US$, p<0.05), and cost for examination (685.5 US$ vs. 958.1 US$, p<0.05) were lower in patients with eosinophilia than those without eosinophilia. CONCLUSION: Eosinophilia serves as a favorable marker for the severity of pneumonia, health-care consumption, and cost of medical care in patients with CAP and COPD.

Nationwide Study of the Epidemiology, Diagnosis, and Treatment of Hypersensitivity Pneumonitis in Korea.

BACKGROUND: Hypersensitivity pneumonitis (HP) is a condition with an uncertain global incidence, and information on its diagnosis and management is limited. This study aimed to address these knowledge gaps. METHODS: This study utilized customized claims data from the Health Insurance Review and Assessment Service (HIRA) in South Korea from January 2010, to December 2021. Patients with HP were identified based on the diagnosis code (International Classification of Diseases, 10th Revision, J67) between 2011 and 2020. Incident HP cases were defined as new HP claims, excluding those with claims in the previous year. The study examined various factors such as age, sex, comorbidities, diagnostic methods, and treatment patterns. Additionally, multivariate logistic regression analysis was performed to identify risk factors associated with treatment initiation. RESULTS: A total of 8,678 HP incident cases were confirmed, with age- and sex-adjusted annual incidence rates ranging from 1.14/100,000 in 2020 to 2.16/100,000 in 2012. The mean age of patients with incident HP was 52 years, with a higher incidence observed among males. Additionally, the most common comorbidity was asthma. Bronchoscopy was performed on 16.9% of patients, and 25.4% of patients did not receive treatment within 1 year of diagnosis. Among those who received treatment, prednisone was the most used systemic steroid, and azathioprine was the most commonly used second-line immunosuppressant. Factors associated with treatment initiation included the female sex, having asthma or gastroesophageal reflux disease (GERD), and undergoing bronchoscopy. CONCLUSION: This study provides valuable insights into the incidence, diagnosis, and treatment patterns of HP in South Korea using nationwide medical claims data.

Correlation of handgrip strength with quality of life-adjusted pulmonary function in adults.

BACKGROUND: Handgrip strength (HGS) is acknowledged as a key indicator of overall physical fitness and is associated with various health outcomes. OBJECTIVES: This research investigates the correlation between HGS and quality of life (QoL), focusing on its relation to pulmonary function in the general adult population. METHOD: The study involved 19,402 participants aged 40 and above, spanning from 2014 to 2019, who underwent pulmonary function and HGS tests. Participants were categorized based on lung function, and regression analyses were employed to examine the relationship between HGS and QoL, with adjustments made for lung function. RESULTS: The average age of the cohort was 58.2 years, comprising 44.6% males and 41.2% smokers. Out of the 18,708 participants who completed the European Quality of Life Scale-Five Dimensions (EQ-5D-3L) assessment, higher severity levels in mobility, self-care, usual activities, pain or discomfort, and anxiety or depression were linked to lower HGS in both sexes. Additionally, among the 3,723 participants who completed the Health-related Quality of Life Instrument with 8 Items (HINT-8) assessment, higher severity levels in pain, work, and depression were associated with lower HGS in men. In women, higher severity levels in climbing stairs, pain, vitality, and work correlated with lower HGS. CONCLUSIONS: As problems indicated by EQ-5D worsened, there was a consistent decrease in handgrip strength (HGS) across both genders. The HINT-8 assessment further revealed that increased severity in pain and work-related issues led to reduced HGS in both men and women. This study highlights the relationship between HGS and Quality of Life (QoL), taking lung function into consideration, and underscores the importance of HGS as a potential marker of physical health and fitness.

Differential Diagnosis of Pleural Effusion Using Machine Learning.

Rationale: Differential diagnosis of pleural effusion is challenging in clinical practice. Objectives: We aimed to develop a machine learning model to classify the five common causes of pleural effusions. Methods: This retrospective study collected 49 features from clinical information, blood, and pleural fluid of adult patients who underwent diagnostic thoracentesis between October 2013 and December 2018. Pleural effusions were classified into the following five categories: transudative, malignant, parapneumonic, tuberculous, and other. The performance of five different classifiers, including multinomial logistic regression, support vector machine, random forest, extreme gradient boosting, and light gradient boosting machine (LGB), was evaluated in terms of accuracy and area under the receiver operating characteristic curve through fivefold cross-validation. Hybrid feature selection was applied to determine the most relevant features for classifying pleural effusion. Results: We analyzed 2,253 patients (training set, n = 1,459; validation set, n = 365; extra-validation set, n = 429) and found that the LGB model achieved the best performance in both validation and extra-validation sets. After feature selection, the accuracy of the LGB model with the selected 18 features was equivalent to that with all 49 features (mean ± standard deviation): 0.818 ± 0.012 and 0.777 ± 0.007 in the validation and extra-validation sets, respectively. The model's mean area under the receiver operating characteristic curve was as high as 0.930 ± 0.042 and 0.916 ± 0.044 in the validation and extra-validation sets, respectively. In our model, pleural lactate dehydrogenase, protein, and adenosine deaminase levels were the most important factors for classifying pleural effusions. Conclusions: Our LGB model showed satisfactory performance for differential diagnosis of the common causes of pleural effusions. This model could provide clinicians with valuable information regarding the major differential diagnoses of pleural diseases.

Sex differences in chronic obstructive pulmonary disease characteristics: the Korea National Health and Nutrition Examination Survey 2007-2018.

BACKGROUND/AIMS: Chronic obstructive pulmonary disease (COPD) is less prevalent in females than males, but it affects mortality in females. There may be sex differences in the clinical characteristics of COPD. METHODS: We analyzed the Korea National Health and Nutrition Examination Survey dataset from 2007 to 2018. We compared the clinical characteristics and comorbidities in subjects with COPD according to sex. We adjusted the multivariate logistic regression of lung cancer prevalence according to COPD and sex by age and smoking amount. RESULTS: Females with COPD tended to be older than males with COPD (64.1 ± 0.4 yr vs. 62.3 ± 0.2 yr, respectively, p < 0.001). Approximately 89% of males with COPD had a smoking history, while 86% of females with COPD were non-smokers (p < 0.001). Household income was lower (p < 0.001) and asthma and overall malignancy were more prevalent in females with COPD than males with COPD (25.5 vs. 11.6%, respectively, p < 0.001; (6.3 vs. 5.4%, respectively, p < 0.001). However, lung cancer was more common in males with COPD than females with COPD (0.9 vs. 0.1%, respectively, p < 0.001). Lung cancer prevalence increased in males with moderate COPD compared to subjects without COPD (OR, 4.409; 95% CI, 1.741-9.419). CONCLUSION: Females with COPD had a lower smoking rate, household income, and lung cancer prevalence than males with COPD. More active COPD screening is needed for women of low socioeconomic status, even if they do not smoke.

Interstitial lung disease following COVID-19 vaccination: a disproportionality analysis using the Global Scale Pharmacovigilance Database (VigiBase).

BACKGROUND AND OBJECTIVE: Despite several case reports, population-based studies on interstitial lung disease (ILD) following COVID-19 vaccination are lacking. Given the unprecedented safety issue of COVID-19 vaccination, it is important to assess the worldwide patterns of ILD following COVID-19 vaccination. This study aimed to investigate the signals of COVID-19 vaccine-associated ILD compared with other vaccinations using disproportionality analysis. METHODS: We analysed the VigiBase database during the period between 13 December 2020 and 26 January 2023. We adopted the case/non-case approach to assess the disproportionality signal of ILD for COVID-19 vaccines via 1:10 matching by age and sex. We compared COVID-19 vaccines with all other vaccines as the reference group. RESULTS: Among 1 233 969 vaccine-related reports, 679 were reported for ILD. The majority of ILD cases were related to tozinameran (376 reports, 55.4%), Vaxzevria (129 reports, 19.0%) and elasomeran (78 reports, 11.5%). The reporting OR of ILD following COVID-19 vaccination was 0.86 (95% CI 0.64 to 1.15) compared with all other vaccines. CONCLUSION: No significant signal of disproportionate reporting of ILD was observed for COVID-19 vaccines compared with all other vaccines. Moreover, when compared with the influenza vaccines that are known to cause ILD, no signal was observed. This study results might help decision-making on the subsequent COVID-19 vaccination strategy of ILD. Further large and prospective studies are required for more conclusive evidence.

Acute exacerbation of COPD increases the risk of hip fractures: a nested case-control study from the Korea National Health Insurance Service.

BACKGROUND/AIMS: Hip fracture and acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) could increase mortality in patients with COPD. There are no data on the relationship between AE-COPD and hip fracture, which may significantly affect the prognosis of patients with COPD. Therefore, we conducted this study to determine the effects of AE-COPD on hip fractures in patients with COPD. METHODS: This retrospective, nested, case-control study included 253,471 patients with COPD (≥ 40 years of age) identified from the Korea National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) from 2002 to 2015. Among 176,598 patients with COPD, 1,415 patients with hip fractures were identified. Each case was matched to one control for age (within 10 years), sex, and year of COPD diagnosis. We estimated the adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for hip fractures associated with AE-COPD using conditional logistic regression analysis, adjusting for underlying diseases and smoking history. RESULTS: In patients with AE-COPD, the risk of hip fracture was 2.50 times higher, regardless of systemic corticosteroid use and underlying disease (aOR, 2.50; 95% CI, 1.67 to 3.75). The risk of hip fracture increased if there was one episode of AE in the year before hip fractures (aOR, 2.25; 95% CI, 1.66 to 3.05). Moreover, the risk of hip fracture also increased in patients with more than two episodes of AE the year before hip fractures (aOR, 2.57; 95% CI, 1.61 to 4.10). CONCLUSION: AE-COPD increases the risk of hip fracture regardless of underlying diseases, including osteoporosis, and treatment with systemic corticosteroids.

Sleep duration and mortality in patients with diabetes: Results from the 2007-2015 Korea national health and nutrition examination survey.

AIM: - To evaluate the association between sleep duration and mortality in adults with type 2 diabetes. METHODS: - This study was a longitudinal analysis of all-cause mortality according to sleep duration based on the 2007-2015 Korea National Health and Nutrition Examination Survey (KNHANES) linked to the Cause of Death data (ver. 1.1). Adult participants with type 2 diabetes were included in the analysis. According to self-reported sleep duration, participants were divided into five groups (≤ 5 [short sleeper], 6, 7, 8, and ≥ 9 h/day [long sleeper]). All missing values were replaced using multiple imputation. We used Cox proportional hazards models to evaluate the relationship between sleep duration and mortality using age as the time scale. RESULTS: - Among the final 51,603 participants who were linked to death certificate data, 5,930 (11.5%) had type 2 diabetes. During a median follow-up of 6.5 years, 735 (12.4%) deaths occurred. In multivariable analysis, a J-shaped association between sleep duration and all-cause mortality was observed (P for quadratic trend = 0.003). In particular, long sleep duration was significantly associated with an increased risk of all-cause mortality (adjusted hazard ratio, 1.65; 95% confidence interval, 1.29-2.11. In addition, modifying effects on the relationship between sleep duration and mortality were identified for chronic kidney disease and cancer (P for interaction = 0.003 and 0.002, respectively). CONCLUSION: - A J-shaped relationship was identified between sleep duration and all-cause mortality in Korean adults with type 2 diabetes. In particular, a long sleep duration was significantly associated with an increased risk of all-cause mortality.

Radiographic severity and treatment outcome of Mycobacterium abscessus complex pulmonary disease.

INTRODUCTION: The lack of reliable predictors for the treatment response complicates decisions to initiate treatment in patients with Mycobacterium abscessus complex pulmonary disease (MABC-PD). We aimed to investigate whether baseline radiographic disease severity is associated with treatment outcome in MABC-PD. METHOD: We retrospectively analyzed 101 patients with MABC-PD (54 with M. abscessus-PD and 47 with M. massiliense-PD) treated in a tertiary referral hospital between January 2006 and December 2019. Using chest computed tomography images, baseline radiographic disease severity was quantitatively scored according to five categories of radiographic lesions (bronchiectasis, bronchiolitis, cavities, nodules, and consolidation). RESULTS: Treatment success was achieved in 53.7% of patients with M. abscessus-PD and 85.1% of patients with M. massiliense-PD. Higher overall scores for baseline radiographic disease severity were associated with treatment failure in patients with M. massiliense-PD (aOR 1.35, 95% CI 1.02-1.79 for each 1-point increase in severity score), as well as in patients with M. abscessus-PD (aOR 1.15, 95% CI 1.00-1.33). This was particularly prominent in patients with overall severity score of ≥14 (aOR 31.16, 95% CI 1.12-868.95 for M. massiliense-PD and aOR 3.55, 95% CI 1.01-12.45 for M. abscessus-PD). Among variable radiographic abnormalities, the score for cavitary lesion severity was associated with treatment failure in patients with M. abscessus-PD (aOR 1.26, 95% CI 1.01-1.56), but not in patients with M. massiliense-PD. CONCLUSIONS: Given the association between baseline radiographic disease severity and treatment outcome, initiating treatment should be actively considered before significant progression of radiographic lesions in patients with MABC-PD.

Usefulness of Post-bronchoscopy Sputum Culture for Diagnosis of Nontuberculous Mycobacterial Pulmonary Disease.

BACKGROUND: Bronchoscopy is recommended for patients with suspected nontuberculous mycobacterial pulmonary disease (NTM-PD) whose sputum culture results are consistently negative or from whom adequate sputum samples cannot be obtained. Post-bronchoscopy sputum (PBS) collection is recommended for patients with suspected tuberculosis who undergo bronchoscopy. However, it remains unclear whether PBS collection can increase the diagnostic yield of NTM-PD. METHODS: Patients with suspected NTM-PD who underwent diagnostic bronchoscopy from January 1, 2017 to June 30, 2020 at the Seoul National University Hospital were included in the study. They were divided into the sputum culture-negative and scanty sputum groups. The results of mycobacterial cultures from bronchial washing specimens and PBS were compared between these groups. RESULTS: In total, 141 patients were included in the study; there were 39 and 102 patients in the sputum culture-negative and scanty sputum groups, respectively. Nontuberculous mycobacteria were cultured from bronchial washing specimens collected from 38.3% (54/141) of all patients (30.7% [12/39] patients in the sputum culture-negative group and 41.2% [42/102] patients in the scanty sputum group; P = 0.345). Nontuberculous mycobacteria were exclusively cultured from PBS collected from 3.5% (5/141) of all patients (7.7% [3/39] patients in the sputum culture-negative group and 2.0% [2/102] patients in the scanty sputum group; P = 0.255). CONCLUSIONS: Additional PBS collection improved diagnostic yield marginally in patients with suspected NTM-PD who undergo bronchoscopy.

Delayed diagnosis of allergic bronchopulmonary aspergillosis due to absence of asthmatic symptoms.

Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disease with small prevalence. Exposure to aspergillus mold causes immunologic hypersensitivity and may cause ranges of symptoms from minimal to detrimental outcomes. Diagnosing and treating the disease before the development of bronchiectasis may save the patient from poor outcomes. This report presents a case of recurrent ABPA without any symptom of asthma, which impeded the correct diagnosis even after numerous hospitalizations.

Seven-day continuous abstinence rate from smoking at 1, 2, or 3 years after the use of varenicline.

BACKGROUND: Varenicline, a selective partial agonist/antagonist of the α4ß2 nicotinic receptor, has proven effectiveness for smoking cessation by several randomized, controlled trials. Because few studies have evaluated the long-term efficacy of varenicline, we tried to evaluate the smoking status of varenicline users up to 3 years after the initial prescription of the drug. METHODS: We interviewed varenicline users who were prescribed the drug from June 2007 to May 2010 by telephone, from June 2010 to May 2011. RESULTS: One-hundred and thirty-three of 250 varenicline users (53.2%) were available for the survey. Seven-day continuous abstinence from smoking was adhered to by 17 of 39 respondents (43.6%) at 1 year, and 11 of 36 (30.6%) and 19 of 58 (32.8%) at 2 and 3 years since the first use of varenicline, respectively. Compared to current smokers, successful quitters were older (55.0 years vs. 49.9 years, p=0.01), had better compliance to the 12-week course (27.7 vs. 9.3%, p=0.01), and had taken varenicline longer (10.1 vs. 5.9 weeks, p=0.01). Fifty-four of 71 current smokers (76.1%) were willing to stop smoking in the near future. The preferred ways to cease smoking were will-power (48.1%), varenicline (25.9%), nicotine replacement therapy (11.1%), and others (14.9%). CONCLUSION: Smokers should be encouraged to stick to the proven way for recommended period of time for successful cessation of smoking.

A case of antiphospholipid syndrome refractory to secondary anticoagulating prophylaxis after deep vein thrombosis-pulmonary embolism.

Antiphospholipid syndrome (APS) is an acquired systemic autoimmune disorder characterized by a combination of clinical criteria, including vascular thrombosis or pregnancy morbidity and elevated antiphospholipid antibody titers. It is one of the causes of deep vein thrombosis and pulmonary embolism that can be critical due to the mortality risk. Overall recurrence of thromboembolism is very low with adequate anticoagulation prophylaxis. The most effective treatment to prevent recurrent thrombosis is long-term anticoagulation. We report on a 17-year-old male with APS, who manifested blue toe syndrome, deep vein thrombosis, pulmonary thromboembolism, and cerebral infarction despite adequate long-term anticoagulation therapy.