BMC Pulmonary Medicine最新文献

Background: Severe acute respiratory infections (SARIs) are a critical public health concern due to their substantial morbidity and mortality rates across age groups. The objective of this study was to investigate the epidemiological characteristics, pathogen distribution, and clinical outcomes of SARIs in South Korea by analyzing nationwide surveillance data.

Methods: We conducted a prospective, multicenter surveillance study from January 2017 to January 2023 across sentinel hospitals nationwide, coordinated by the Korea Disease Control and Prevention Agency (KDCA). Respiratory specimens were collected and tested for a panel of viral and bacterial pathogens. Clinical data and outcomes were analyzed according to pathogen detection status.

Results: A total of 47,857 hospitalized patients with SARIs were enrolled based on standardized criteria: fever (≥ 38 °C), cough, and symptom onset within 10 days prior to hospitalization. Pathogens were identified in 52.5% of enrolled patients. The group that tested positive for pathogens was significantly younger (median age of 4.0 years) than the group that tested negative (median age of 59.0 years). Viral pathogens were more prevalent in children, whereas bacterial pathogens, such as Streptococcus pneumoniae, were more prevalent in older adults. Seasonal trends were observed: influenza and respiratory syncytial virus (RSV) peaked in winter; rhinovirus circulated year-round; and SARS-CoV-2 showed irregular peaks. Patients with confirmed pathogens had higher rates of pneumonia and mortality, as well as longer hospital stays (P < 0.001), compared to patients without confirmed pathogens. Antivirals were more commonly used in the pathogen-positive group, while antibiotics were predominantly prescribed to patients without confirmed pathogens. Geographic and sex-specific variations in pathogen distribution were also identified.

Conclusions: This study provides a thorough examination of the epidemiology of SARIs in South Korea over a six-year period. The findings reveal notable differences in pathogen prevalence and related clinical outcomes by age, season, and region. These results underscore the importance of sustained nationwide surveillance and the development of targeted, seasonally adaptive public health strategies to mitigate the impact of SARIs on vulnerable populations.

Background: Volatile organic compounds (VOCs) derived from exhaled breath have been studied for their diagnostic potential in chronic obstructive pulmonary disease (COPD). However, the diagnostic efficacy of detection technologies of electronic nose (eNose) and gas chromatography-mass spectrometry (GC-MS) remains unclear. This study aims to systematically compare the diagnostic performance of these two methods in COPD diagnosis.

Methods: This review was conducted in accordance with PRISMA guidelines. Relevant studies were retrieved from databases including PubMed, EMBASE, Cochrane, SciFinder and Web of Science, with a cutoff date of April 30, 2025. Two researchers screened the literature, extracted data, and evaluated the quality of the studies using the QUADAS-2 tool. A bivariate model was used to perform meta-analyses of sensitivity, specificity and heterogeneity for the eNose and GC-MS detection methods.

Results: A total of 39 studies were included in the systematic review, involving 2363 COPD patients and 1570 healthy controls. Among these, 18 studies were incorporated into the meta-analysis, with the pooled sensitivity and specificity of VOCs for differentiating COPD patients from controls being 83% and 78%, respectively. For specific VOCs detection methods, both GC-MS and eNose showed comparable pooled sensitivity of 0.83 and 0.82 respectively. However, eNose demonstrated a significantly higher pooled specificity (0.84; 95% CI: 0.79-0.89) and area under the sROC curve (AUC: 0.9011) than GC-MS with the specificity of 0.70 (95% CI: 0.63-0.75) and an AUC of 0.8764.

Conclusion: This study revealed that VOCs can distinguish COPD patients from healthy controls. While both GC-MS and eNose demonstrated comparable sensitivity, GC-MS - considered the gold standard method for VOCs detection - showed lower specificity and AUC values than eNose in differentiating COPD patients from controls, suggesting that eNose has a lower misdiagnosis rate for COPD. These result may be influenced by the heterogeneity due to the variations in COPD disease stages or differences in breath portion across studies. Future research is recommended to standardize case inclusion criteria and conduct multicenter head-to-head validation studies.

Background: Progressive pulmonary fibrosis (PPF) represents a challenging phenotype of interstitial lung disease (ILD), characterised by functional deterioration and radiological progression despite treatment. The identification of reliable biomarkers to predict PPF remains a critical unmet need in clinical practice. This study aimed to investigate the predictive value of serum cytokeratin 19 fragment (CYFRA21-1) for PPF in patients with non-idiopathic pulmonary fibrosis (non-IPF) ILD.

Methods: A retrospective cohort of 203 patients with non-IPF ILD were enrolled between January 2020 and December 2021 and followed for a median of 19 months. Baseline serum CYFRA21-1 levels were measured, and progression to PPF was defined according to the 2022 ATS clinical guideline. Associations between CYFRA21-1 levels and PPF risk were analysed using Cox proportional hazards models, and the optimal cut-off value was determined by receiver operating characteristic curve analysis.

Results: During follow-up, 48 patients (23.6%) developed PPF. Baseline CYFRA21-1 levels were significantly higher in the PPF group than in the non-PPF group (5.54 [4.36, 8.44] vs. 3.73 [2.63, 5.21] ng/mL, P < 0.001). Following variable selection via Least Absolute Shrinkage and Selection Operator (LASSO) regression, CYFRA21-1 was identified as an independent predictor of PPF in the multivariate Cox model (hazard ratio [HR] = 1.085, 95% confidence interval: 1.018-1.156, P = 0.013). The optimal cut-off value for CYFRA21-1 was determined to be 5.12 ng/mL (area under the curve = 0.712). Patients stratified by this cut-off (high vs. low CYFRA21-1) demonstrated significant differences in baseline lung function and computed tomography severity scores. Moreover, the high CYFRA21-1 group was associated with a substantially increased risk of PPF progression (HR = 3.803, P < 0.001).

Conclusions: Elevated serum CYFRA21-1 levels independently predict the development of PPF in patients with non-IPF ILD. It is correlated with impaired pulmonary function and radiographic severity. CYFRA21-1 may serve as a valuable biomarker for early risk stratification, supporting the need for validation in prospective multicentre studies.

Objective: Obstructive sleep apnea (OSA) is associated with metabolic dysregulation, potentially affecting ketone body metabolism. However, relationships between OSA and ketone body metabolism require further investigation. Thus, in this study, we investigated relationships between breath acetone levels and OSA manifestations (e.g., hypoxia and arousal events).

Methods: Baseline characteristics were collected from 66 eligible participants, and breath acetone levels were measured before and after polysomnography (PSG). Participants were categorized into two groups using the apnea-hypopnea index (AHI): normal-to-mild (< 15 events/h) and moderate-to-severe (≥ 15 events/h) OSA groups. Differences in baseline characteristics, PSG parameters, and breath acetone levels between the two groups were analyzed. Next, correlations analyses and multivariable regression models adjusted for baseline characteristics were performed to examine relationships between alterations in breath acetone levels and various sleep parameters.

Results: Significant differences were observed between the two groups in baseline characteristics, sleep quality indices and the overnight difference in acetone levels (all p < 0.01). Additionally, the overnight difference in acetone levels exhibited significant negative correlations (p < 0.01) with the AHI, arousal index (ArI), and snoring index. In regression models adjusted for confounding factors, this overnight acetone difference remained significantly and negatively associated with both AHI and ArI values (both p < 0.05).

Conclusions: The present observations provide insight into potential links between overnight breath acetone alterations and OSA manifestations.

Asthma is a prevalent inflammatory condition of the lower respiratory tract, affecting over 272 million people worldwide. Although prevalence and mortality rates have declined, asthma continues to burden healthcare systems, particularly in low-income regions. Metabolic diseases significantly influence the development and progression of asthma. This study aimed to evaluate global, regional, national, and temporal trends in asthma burden attributable to metabolic diseases from 1990 to 2021 and to project changes through 2040. The GBD (Global Burden of Disease) 2021 dataset was used to analyze key epidemiological variables, focusing on disability survival, years of life lost, and disability-adjusted life years (DALYs). Descriptive analyses and trend evaluations illustrated the burden of asthma due to metabolic diseases (MAS) over the last 30 years, while decomposition analyses quantified the impacts of population growth, aging, and epidemiological changes. In 2021, deaths totaled 62,363, with DALYs reaching over 3.28 million. High socio-demographic index (SDI) quintiles reported the highest age-standardized rates of DALYs and years of disability (YLDs), while low-middle SDI quintiles had the highest death rates. South Asia experienced the highest number of MAS-related deaths, years of life lost (YLLs), and DALYs. From 1990 to 2020, rates of deaths, DALYs, YLLs, and YLDs declined, with the most significant decrease occurring from 1993 to 2000. The analysis indicated that females bore a greater burden than males, with changes in DALYs more influenced by population growth. Inequalities associated with SDI decreased significantly, with a notable reduction in the health concentration index. Despite progress in prevention and treatment, the number of MAS cases is expected to continue rising until 2040, highlighting the need for effective public health strategies and ongoing research.

Background: Severe asthma (SA) is a heterogeneous disease composed of various clinical phenotypes, and criteria for selecting the most appropriate biological agent remain unclear. Therefore, when optimal control cannot be achieved with the initial biological therapy, switching between biological drugs is often performed.

Methods: This real-world study evaluated patients with severe asthma who initiated omalizumab treatment. Based on their treatment response, patients were divided into two groups: those who continued omalizumab and those who switched to mepolizumab or benralizumab. Clinical data were evaluated before biological treatment, after omalizumab therapy, and following the second biological therapy. Additionally, factors influencing the decision to switch and the effectiveness of the switch were analyzed.

Results: Of the total 51 patients, 45.1% (n = 23) switched to a second biological agent due to inadequate response to the initial treatment. In the "Switch" group, baseline forced expiratory volume in one second (FEV₁) levels were significantly lower, while blood eosinophil counts (BEC) and exacerbation frequency were higher (p < 0.05). Although limited clinical improvement was observed after omalizumab treatment, significant improvements in asthma control test (ACT) scores, FEV₁, BEC, exacerbations, and hospitalizations were noted following the second biological therapy (p < 0.001). Low baseline FEV₁, high BEC, and frequent exacerbations were the main predictors of the decision to switch.

Conclusions: In severe asthma patients who do not achieve adequate control with omalizumab, switching to interleukin-5 (IL-5) targeted biological therapies may provide clinically significant improvements. Baseline clinical parameters can serve as useful predictors for the need to change biological treatment.