Establishment and application of reference equations for FEF50 and FEF75 in the Chinese population

Background

Reference equations for forced expiratory flow at 50% and 75% of forced vital capacity (FVC) (FEF50 and FEF75) in the Chinese population are lacking. It is of great importance to establish equations covering most age groups and to study their applicability in clinical practice.

Methods

Using the lambda-mu-sigma (LMS) method, reference equations for FEF50 and FEF75 were constructed based on pulmonary function data from healthy subjects collected from January 2007 to June 2010 at 24 centers throughout China. Differences between the established equations and extraneous equations were compared using standardized means (Z values) and percentage errors (PE). The proportion of small airway dysfunction (SAD) defined by the present equations was calculated. The Fisher precision probability test and the Mann-Whitney test were used to analyze the magnitude of changes in small and large airway indices after bronchodilator inhalation in patients with suspected asthma and chronic obstructive pulmonary disease (COPD).

Results

Reference equations for FEF50 and FEF75 were established based on data from 7,115 healthy individuals (aged 4 to 80 years, 50.9% female, height between 95 and 190 cm). The present equations (all Z values were -0.0 and PE ranged from 2.0% to 4.2%) showed advantages over the European Community for Steel and Coal (ECSC) equations in 1993 (with Z values ranging from -0.7 to -0.2 and PE ranged from -23.4% to -4.5%). A total of 4,356 patients with suspected asthma (51.1% female; a mean age of 45.4 years) and 6,558 patients with suspected COPD (10.1% female; a mean age of 65.0 years) were included. The present equations defined 95.7% and 99.9% of SAD in these patients. After bronchodilator inhalation, greater mean improvement rates in small airway indices were observed both in patients with suspected asthma [mean ± standard deviation (SD) =48%±47%] and in patients with suspected COPD (mean ± SD =20%±30%) (P<0.05).

Conclusions

The reference equations for FEF50 and FEF75 established in this study should be considered for use in China. Further studies are needed to validate their value in the diagnosis of some chronic respiratory diseases.

Hospitalization, case fatality, comorbidities, and isolated pathogens of adult inpatients with pneumonia from 2013 to 2022: a real-world study in Guangzhou, China

BACKGROUND

In the context of increasing population aging, ongoing drug-resistant pathogens and the COVID-19 epidemic, the changes in the epidemiological and clinical characteristics of patients with pneumonia remain unclear. This study aimed to assess the trends in hospitalization, case fatality, comorbidities, and isolated pathogens of pneumonia-related adult inpatients in Guangzhou during the last decade.

METHODS

We retrospectively enrolled hospitalized adults who had doctor-diagnosed pneumonia in the First Affiliated Hospital of Guangzhou Medical University from January 1, 2013 to December 31, 2022. A natural language processing system was applied to automatically extract the clinical data from electronic health records. We evaluated the proportion of pneumonia-related hospitalizations in total hospitalizations, pneumonia-related in-hospital case fatality, comorbidities, and species of isolated pathogens during the last decade. Binary logistic regression analysis was used to assess predictors for patients with prolonged length of stay (LOS).

RESULTS

A total of 38,870 cases were finally included in this study, with 70% males, median age of 64 (53, 73) years and median LOS of 7.9 (5.1, 12.8) days. Although the number of pneumonia-related hospitalizations showed an upward trend, the proportion of pneumonia-related hospitalizations decreased from 199.6 per 1000 inpatients in 2013 to 123.4 per 1000 in 2021, and the case fatality decreased from 50.2 per 1000 in 2013 to 23.9 per 1000 in 2022 (all P < 0.05). The most common comorbidities were chronic obstructive pulmonary disease, lung malignancy, cardiovascular diseases and diabetes. The most common pathogens were Pseudomonas aeruginosa, Candida albicans, Acinetobacter baumannii, Stenotrophomonas maltophilia, Klebsiella pneumoniae, and Staphylococcus aureus. Glucocorticoid use during hospitalization (Odd Ratio [OR] = 1.86, 95% Confidence Interval (CI): 1.14-3.06), immunosuppressant use during hospitalization (OR = 1.99, 1.14-3.46), ICU admission (OR = 16.23, 95%CI: 11.25-23.83), receiving mechanical ventilation (OR = 3.58, 95%CI: 2.60-4.97), presence of other underlying diseases (OR = 1.54, 95%CI: 1.15-2.06), and elevated procalcitonin (OR = 1.61, 95%CI: 1.19-2.19) were identified as independent predictors for prolonged LOS.

CONCLUSION

The proportion of pneumonia-related hospitalizations and the in-hospital case fatality showed downward trends during the last decade. Pneumonia inpatients were often complicated by chronic underlying diseases and isolated with gram-negative bacteria. ICU admission was a significant predictor for prolonged LOS in pneumonia inpatients.

Supervised training models with or without manual lesion delineation outperform clinicians in distinguishing pulmonary cryptococcosis from lung adenocarcinoma on chest CT

BACKGROUND

The role of artificial intelligence (AI) in the discrimination between pulmonary cryptococcosis (PC) and lung adenocarcinoma (LA) warrants further research.

OBJECTIVES

To compare the performances of AI models with clinicians in distinguishing PC from LA on chest CT.

METHODS

Patients diagnosed with confirmed PC or LA were retrospectively recruited from three tertiary hospitals in Guangzhou. A deep learning framework was employed to develop two models: an undelineated supervised training (UST) model utilising original CT images, and a delineated supervised training (DST) model utilising CT images with manual lesion annotations provided by physicians. A subset of 20 cases was randomly selected from the entire dataset and reviewed by clinicians through a network questionnaire. The sensitivity, specificity and accuracy of the models and the clinicians were calculated.

RESULTS

A total of 395 PC cases and 249 LA cases were included in the final analysis. The internal validation results for the UST model showed a sensitivity of 85.3%, specificity of 81.0%, accuracy of 83.6% and an area under the curve (AUC) of 0.93. Similarly, the DST model exhibited a sensitivity of 88.2%, specificity of 88.1%, accuracy of 88.2% and an AUC of 0.94. The external validation of the two models yielded AUC values of 0.74 and 0.77, respectively. The average sensitivity, specificity and accuracy of 102 clinicians were determined to be 63.1%, 53.7% and 59.3%, respectively.

CONCLUSIONS

Both models outperformed the clinicians in distinguishing between PC and LA on chest CT, with the UST model exhibiting comparable performance to the DST model.

Distinguishing bronchoscopically observed anatomical positions of airway under by convolutional neural network

Background

Artificial intelligence (AI) technology has been used for finding lesions via gastrointestinal endoscopy. However, there were few AI-associated studies that discuss bronchoscopy.

Objectives

To use convolutional neural network (CNN) to recognize the observed anatomical positions of the airway under bronchoscopy.

Design

We designed the study by comparing the imaging data of patients undergoing bronchoscopy from March 2022 to October 2022 by using EfficientNet (one of the CNNs) and U-Net.

Methods

Based on the inclusion and exclusion criteria, 1527 clear images of normal anatomical positions of the airways from 200 patients were used for training, and 475 clear images from 72 patients were utilized for validation. Further, 20 bronchoscopic videos of examination procedures in another 20 patients with normal airway structures were used to extract the bronchoscopic images of normal anatomical positions to evaluate the accuracy for the model. Finally, 21 respiratory doctors were enrolled for the test of recognizing corrected anatomical positions using the validating datasets.

Results

In all, 1527 bronchoscopic images of 200 patients with nine anatomical positions of the airway, including carina, right main bronchus, right upper lobe bronchus, right intermediate bronchus, right middle lobe bronchus, right lower lobe bronchus, left main bronchus, left upper lobe bronchus, and left lower lobe bronchus, were used for supervised machine learning and training, and 475 clear bronchoscopic images of 72 patients were used for validation. The mean accuracy of recognizing these 9 positions was 91% (carina: 98%, right main bronchus: 98%, right intermediate bronchus: 90%, right upper lobe bronchus: 91%, right middle lobe bronchus 92%, right lower lobe bronchus: 83%, left main bronchus: 89%, left upper bronchus: 91%, left lower bronchus: 76%). The area under the curves for these nine positions were >0.98. In addition, the accuracy of extracting the images via the video by the trained model was 94.7%. We also conducted a deep learning study to segment 10 segment bronchi in right lung, and 8 segment bronchi in Left lung. Because of the problem of radial depth, only segment bronchi distributions below right upper bronchus and right middle bronchus could be correctly recognized. The accuracy of recognizing was 84.33 ± 7.52% by doctors receiving interventional pulmonology education in our hospital over 6 months.

Conclusion

Our study proved that AI technology can be used to distinguish the normal anatomical positions of the airway, and the model we trained could extract the corrected images via the video to help standardize data collection and control quality.

REALizing and improving management of stable COPD in China: results of a multicentre, prospective, observational study (REAL)

BACKGROUND

Chronic obstructive pulmonary disease (COPD) management in China is far from adequate; underdiagnosis and undertreatment are major barriers to optimal care and improved patient outcomes.

OBJECTIVE

To generate reliable information on COPD management, outcomes, treatment patterns and adherence, and disease knowledge in China in a real-world setting.

DESIGN

A 52-week multicentre, prospective, observational study.

METHODS

Outpatients (⩾40 years old) diagnosed with COPD were enrolled from 50 secondary and tertiary hospitals across six geographical regions. Data were collected in routine clinical practice.

RESULTS

Between June 2017 and January 2019, 5013 patients were enrolled and 4978 included in the analysis. Mean [standard deviation (SD)] age was 66.2 (8.9) years, 79.5% were male and 90% had moderate-to-very-severe airflow limitation. Annual rates of overall and severe exacerbation were 0.56 and 0.31, respectively. During 1 year, 1536 (30.8%) patients experienced ⩾1 exacerbation and 960 (19.3%) patients had ⩾1 exacerbation requiring hospitalization/emergency visit. Mean (SD) COPD assessment test score was 14.6 (7.6) at baseline and 10.6 (6.8) at follow-up; however, 42-55% of patients had persistent dyspnoea, chest tightness and wheezing at 1 year. The most prescribed treatments were inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA) (36.0%), ICS/LABA + long-acting muscarinic antagonist (LAMA) (17.7%) and LAMA monotherapy (15.3%). Among patients with high exacerbation risk (GOLD Groups C and D), 10.1% and 13.1%, respectively, did not receive any long-acting inhalers; only 53.8% and 63.6% of Group C and D patients with ⩾1 exacerbation during follow-up were prescribed ICS-containing therapy, respectively. Mean (SD) adherence for long-acting inhalers was 59.0% (34.3%). Mean (SD) score for the COPD questionnaire was 6.7 (2.4).

CONCLUSION

These results indicate a high burden of severe exacerbations and symptoms in Chinese outpatients with COPD, and low adherence with treatment guidelines, highlighting the need for more effective management nationwide.

REGISTRATION

The trial was registered on 20 March 2017 (ClinicalTrials.gov identifier: NCT03131362).

Treatment patterns in patients with stable COPD in China: analysis of a prospective, 52-week, nationwide, observational cohort study (REAL)

BACKGROUND

Underdiagnosis and undertreatment pose major barriers to optimal management of chronic obstructive pulmonary disease (COPD) in China.

OBJECTIVE

The REAL trial was performed to generate reliable information on real-world COPD management, outcomes and risk factors among Chinese patients. Here, we present study outcomes related to COPD management.

DESIGN

It is a 52-week, prospective, observational, multicentre study.

METHODS

Outpatients (aged ⩾40 years) enrolled from 50 secondary and tertiary hospitals across six geographic regions of China were followed up for 12 months, with two onsite visits and by telephone every 3 months following baseline.

RESULTS

Between June 2017 and January 2019, 5013 patients were enrolled and 4978 included in the analysis. Mean [standard deviation (SD)] age was 66.2 (8.9) years, the majority of patients were male (79.5%) and mean (SD) time since COPD diagnosis was 3.8 (6.2) years. The most common treatments at each study visit were inhaled corticosteroids/long-acting beta-agonists (ICSs/LABAs; 28.3-36.0%), long-acting muscarinic antagonists (LAMAs; 13.0-16.2%) and ICS/LABA + LAMA (17.5-18.7%), but up to 15.8% of patients at each visit received neither ICS nor long-acting bronchodilators. The use of ICS/LABA, LAMA and ICS/LABA + LAMA differed across regions and hospital tiers; up to fivefold, more patients received neither ICS nor long-acting bronchodilators in secondary (17.3-25.4%) versus tertiary hospitals (5.0-5.3%). Overall, rates of nonpharmacological management were low. Direct treatment costs increased with disease severity, but the proportion of direct treatment costs incurred due to maintenance treatment decreased with disease severity.

CONCLUSION

ICS/LABA, LAMA and ICS/LABA + LAMA were the most frequently prescribed maintenance treatments for patients with stable COPD in China, although their use differed between region and hospital tier. There is a clear need for improved COPD management across China, particularly in secondary hospitals.

REGISTRATION

The trial was registered on 20 March 2017 (ClinicalTrials.gov identifier: NCT03131362; https://clinicaltrials.gov/ct2/show/NCT03131362).

PLAIN LANGUAGE SUMMARY

Treatment patterns in patients with COPD in ChinaBackground: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease characterized by progressive and irreversible airflow limitation. In China, many patients with this disease do not receive a diagnosis or appropriate treatment.Objective: This study aimed to generate reliable information on the treatment patterns among patients with COPD in China to help inform future management strategies.Study design and methods: Patients (aged ⩾40 years) were enrolled from 50 hospitals across 6 regions of China and physicians collected data over the course of 1 year during routine outpatient visits.Results: The majority of patients were receiving long-acting inhaled treatments, which are recommended to prevent worsening of the disease. Up to 16% of patients in this study, however, did not receive any of these recommended treatments. The proportion of patients who received long-acting inhaled treatments differed across regions and hospital tiers; there were about five times more patients in secondary hospitals (about 25%) who did not receive these treatments compared with those in tertiary hospitals (about 5%). Guidelines recommend that pharmacological treatment should be complemented by nondrug treatment, but this was only received by a minority of patients in this study. Patients with higher disease severity incurred greater direct treatment costs compared with those with milder disease. Maintenance treatment costs made up a smaller proportion of overall direct costs for patients with higher disease severity (60-76%) compared with patients with milder disease (81-94%).Conclusion: Long-acting inhaled treatments were the most frequently prescribed maintenance treatments among patients with COPD in China, but their use differed between region and hospital tier. There is a clear need to improve disease management across China, especially in secondary hospitals.

Exacerbation in patients with stable COPD in China: analysis of a prospective, 52-week, nationwide, observational cohort study (REAL)

BACKGROUND

Chronic obstructive pulmonary disease (COPD) management in China is inadequate and there is a need to improve care and outcomes for patients nationwide.

OBJECTIVES

The REAL study was designed to generate reliable information on COPD management from a representative sample of Chinese patients with COPD. Here, we present study outcomes related to acute exacerbations.

DESIGN

A 52-week, multicentre, prospective, observational study.

METHODS

Outpatients (aged ⩾ 40 years) enrolled from 25 tertiary and 25 secondary hospitals across six geographic regions in China were followed for 12 months. Risk factors for COPD exacerbation and disease severity by exacerbation were assessed using multivariate Poisson and ordinal logistic regression models, respectively.

RESULTS

Between June 2017 and January 2019, 5013 patients were enrolled, with 4978 included in the analysis. Mean (standard deviation) age was 66.2 (8.9) years. More patients presented with exacerbations in secondary versus tertiary hospitals (59.4% versus 40.2%) and in rural versus urban areas (53.2% versus 46.3%). Overall exacerbation rates differed across regions (range: 0.27-0.84). Patients from secondary versus tertiary hospitals had higher rates of overall exacerbation (0.66 versus 0.47), severe exacerbation (0.44 versus 0.18) and exacerbation that resulted in hospitalisation (0.41 versus 0.16). Across regions and hospital tiers, the rates of overall exacerbation and exacerbations that resulted in hospitalisation were highest in patients with very severe COPD (based on the severity of airflow limitation or GOLD 2017 combined assessment). Strong predictors of exacerbation included demographic and clinical characteristics, modified Medical Research Council scores, mucus purulence, exacerbation history and the use of maintenance mucolytic treatment.

CONCLUSION

COPD exacerbation rates varied across regions and were higher in secondary compared with tertiary hospitals in China. Understanding the factors associated with COPD exacerbation may facilitate improved management of COPD exacerbations in China.

REGISTRATION

The trial was registered on 20 March 2017 (ClinicalTrials.gov: NCT03131362; https://clinicaltrials.gov/ct2/show/NCT03131362).

PLAIN LANGUAGE SUMMARY

Exacerbations in patients with chronic obstructive pulmonary disease in ChinaBackground: Chronic obstructive pulmonary disease (COPD) causes progressive and irreversible airflow limitation. As the disease progresses, patients often experience a flare up of symptoms referred to as an exacerbation. There is inadequate management of COPD in China and, therefore, there is a need to improve care and outcomes for patients across the country.Objective: This study aimed to generate reliable information on exacerbations among Chinese patients with COPD to help inform future management strategies.Study design and methods: Patients (aged ⩾ 40 years) were enrolled from 25 secondary and 25 tertiary hospitals across six regions of China. Physicians collected data over 1 year during routine outpatient visits.Results: There were more patients who experienced an exacerbation in secondary versus tertiary hospitals (59% versus 40%) and in rural versus urban areas (53% versus 46%). Patients in different geographic regions experienced varying frequencies of exacerbations over 1 year. Compared with patients from tertiary hospitals, patients from secondary hospitals experienced exacerbations (including exacerbations that were severe and those that resulted in hospitalisation) at a higher frequency over 1 year. Patients with very severe disease experienced exacerbations (including exacerbations that resulted in hospitalisation) at the highest frequency over 1 year, regardless of the patient's geographic region or hospital tier. Patients who had certain characteristics and symptoms, had exacerbation(s) over the previous year, or received medication that aids in the clearance of mucus were more likely to experience exacerbations.Conclusion: The frequency of exacerbations among Chinese patients with COPD varied between patients living in different geographic regions and between patients presenting to different hospital tiers. Understanding the factors related to the occurrence of an exacerbation may help physicians better manage the disease.

Regularity and mechanism of fake crackle noise in an electronic stethoscope

Background: Electronic stethoscopes are widely used for cardiopulmonary auscultation; their audio recordings are used for the intelligent recognition of cardiopulmonary sounds. However, they generate noise similar to a crackle during use, significantly interfering with clinical diagnosis. This paper will discuss the causes, characteristics, and occurrence rules of the fake crackle and establish a reference for improving the reliability of the electronic stethoscope in lung auscultation. Methods: A total of 56 participants with healthy lungs (no underlying pulmonary disease, no recent respiratory symptoms, and no adventitious lung sound, as confirmed by an acoustic stethoscope) were enrolled in this study. A 30-s audio recording was recorded from each of the nine locations of the larynx and lungs of each participant with a 3M Littmann 3200 electronic stethoscope, and the audio was output in diaphragm mode and auscultated by the clinician. The doctor identified the fake crackles and analyzed their frequency spectrum. High-pass and low-pass filters were used to detect the frequency distribution of the fake crackles. Finally, the fake crackle was artificially regenerated to explore its causes. Results: A total of 500 audio recordings were included in the study, with 61 fake crackle audio recordings. Fake crackles were found predominantly in the lower lung. There were significant differences between lower lung and larynx (p < 0.001), lower lung and upper lung (p = 0.005), lower lung and middle lung (p = 0.005), and lower lung and infrascapular region (p = 0.027). Furthermore, more than 90% of fake crackles appeared in the inspiratory phase, similar to fine crackles, significantly interfering with clinical diagnosis. The spectral analysis revealed that the frequency range of fake crackles was approximately 250-1950 Hz. The fake crackle was generated when the diaphragm of the electronic stethoscope left the skin slightly but not completely. Conclusion: Fake crackles are most likely to be heard when using an electronic stethoscope to auscultate bilateral lower lungs, and the frequency of a fake crackle is close to that of a crackle, likely affecting the clinician's diagnosis.

Development and validation of a novel nomogram to predict chronic total occlusion before coronary angiography

OBJECTIVE

Some previous studies have analyzed potential predictors related to the high incidence rate of coronary artery disease (CAD) and established a relevant nomogram for CAD in patients before coronary angiography (CAG). Nevertheless, there are still few models to predict chronic total occlusion (CTO). In this study, we aimed to construct a risk model and nomogram that could effectively predict the probability of CTO before CAG.

PATIENTS AND METHODS

In total, the derivation set (n=1,105) and the validation set (n=368), which included patients with CAG diagnosis of CTO, were collected. A statistical difference test was performed for clinical, demography, echocardiography, medication history, laboratory indexes, and angiography. Univariate and multivariate logistic regression analysis were performed to determine the independent risk factors that affect the diagnosis of CTO. A nomogram was established and validated based on the independent predictors. The area under the curve (AUC), the calibration curve, and the decision curve analysis (DCA) were used to evaluate the nomogram.

RESULTS

The incidence of CTO within CAD was 21.5%. Univariate and multivariate logistic regression analysis revealed that risk factors for gender (male), neutrophil percentage (NE%), hematocrit (HCT), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), ejection fraction (EF), troponin I (TnI), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were independent predictors of CTO. A nomogram was constructed incorporating these independent predictors with good discrimination (0.746 in the C-index) and external validation (0.741 in the C-index). The calibration curves and the DCA showed the reliability and accuracy of this clinical prediction model.

CONCLUSIONS

The nomogram, composed of gender, NE%, HCT, TC, HDL, EF, TnI, and NT-proBNP, can be used for the prediction of CTO in CAD patients, which opens a great possibility of enriching the means to predict the prognosis of these patients in clinical practice. More studies are needed to validate the effectiveness of this nomogram in other populations.

Estimation of lung age via a spline method and its application in chronic respiratory diseases

Lung age is a simplified concept that makes spirometry data easier to understand, but it is not widely used due to limitations in estimation methods. The aim of this study was to develop new equations to estimate lung age and to explore the application value of lung age in chronic respiratory diseases. Retrospective spirometric data of 18- to 80-year-old healthy subjects were used to develop the lung age estimation equations. Models were respectively built by multiple linear regression, piecewise linear regression, and the natural cubic spline method. Patients with chronic obstructive pulmonary disease (COPD) and asthma were subdivided into stages I–IV according to the severity of airflow limitation under the recommendation of the Global Initiative for Chronic Obstructive Lung Disease. Propensity score matching was performed to balance age, height and sex between healthy subjects and patients. The difference between lung age and chronological age (∆ lung age) of patients with COPD and asthma was analyzed. A total of 3409 healthy subjects, 280 patients with COPD and 285 patients with asthma data were included in the analysis. The lung age estimation equation with the best goodness of fit was built by the spline method and composed of FEV₁, FEF_50%, FEF_75% and height as explanatory variables. ∆ lung age progressively increased with the degree of airflow limitation in patients with COPD or asthma. Lung age estimation equations were developed by a spline modeling method. Lung age may be used in the assessment of chronic respiratory patients.

Development and clinical application of an electronic health record quality control system for pulmonary aspergillosis based on guidelines and natural language processing technology

Background

There are considerable differences in the diagnosis and treatment of pulmonary aspergillosis (PA) between specialized hospitals and primary hospitals or developed areas and underdeveloped areas in China. There is a lack of electronic systems that assist respiratory physicians in standardizing the diagnosis and treatment of PA.

Methods

We extracted 26 quality control points from the latest guidelines related to PA, and developed a PA quality control system of electronic health record (EHR) based on natural language processing (NLP) techniques. We obtained PA patient records in the Department of Respiratory Medicine of the First Affiliated Hospital of Guangzhou Medical University to verify the effectiveness of the system comparing with manually evaluation of respiratory experts.

Results

We successfully developed quality control system of PA; 699 PA medical records from EHR of the First Affiliated Hospital of Guangzhou Medical University between January 2015 and March 2020 were obtained and assessed by the system; 162 defects were found, which included 19 medical records with diagnostic defects, 76 medical records with examination defects, and 80 medical records with treatment defects; 200 medical records were sampled for validation, and found that the sensitivity and accuracy of quality control system for pulmonary aspergillosis (QCSA) were 0.99 and 0.96, F1 value was 0.85, and the recall rate was 0.77 compared with experts' evaluation.

Conclusions

Our system successfully uses medical guidelines and NLP technology to detect defects in the diagnosis and treatment of PA, which helps to improve the management quality of PA patients.

Deep Learning for Automatic Upper Airway Obstruction Detection by Analysis of Flow-Volume Curve

BACKGROUND

Due to the similar symptoms of upper airway obstruction to asthma, misdiagnosis is common. Spirometry is a cost-effective screening test for upper airway obstruction and its characteristic patterns involving fixed, variable intrathoracic and extrathoracic lesions. We aimed to develop a deep learning model to detect upper airway obstruction patterns and compared its performance with that of lung function clinicians.

METHODS

Spirometry records were reviewed to detect the possible condition of airway stenosis. Then they were confirmed by the gold standard (e.g., computed tomography, endoscopy, or clinic diagnosis of upper airway obstruction). Images and indices derived from flow-volume curves were used for training and testing the model. Clinicians determined cases using spirometry records from the test set. The deep learning model evaluated the same data.

RESULTS

Of 45,831 patients' spirometry records, 564 subjects with curves suggesting upper airway obstruction, after verified by the gold standard, 351 patients were confirmed. These cases and another 200 cases without airway stenosis were used as the training and testing sets. 432 clinicians evaluated 20 cases of each of the three patterns and 20 no airway stenosis cases (n = 80). They assigned an accuracy of 41.2% (±15.4) (interquartile range: 27.5-52.5%), with poor agreements (κ = 0.12). For the same cases, the model generated a correct detection of 81.3% (p < 0.0001).

CONCLUSIONS

Deep learning could detect upper airway obstruction patterns from other classic patterns of ventilatory defects with high accuracy, whereas clinicians presented marked errors and variabilities. The model may serve as a support tool to enhance clinicians' correct diagnosis of upper airway obstruction using spirometry.

Severity distribution and treatment of chronic obstructive pulmonary disease in China: baseline results of an observational study

Background

Chronic obstructive pulmonary disease (COPD) receives low awareness and is undertreated in China. Understanding the burden and treatment of COPD across the nation is important for improving quality of care for this disease. This study aims to reveal the current situation of COPD severity distribution and management across China.

Methods

Baseline data from REALizing and Improving Management of Stable COPD in China, a multicentre, prospective, longitudinal, observational study, were analysed. Patients diagnosed with COPD as per Global Initiative for Chronic Obstructive Lung Disease 2016 (GOLD 2016) criteria were enrolled from 50 randomly selected hospitals (tertiary, 25; secondary, 25) across six geographical regions. Data were collected in routine clinical settings.

Results

Between 15 December 2017 and 6 August 2020, 5013 patients were enrolled and 4978 included in the full analysis set. Of these, 2459 (49.4%) reported ≥ 1 exacerbation within 12 months prior to study enrolment, with a mean annual rate of 0.9/patient, including 0.2/patient and 0.5/patient leading to emergency room visits and hospitalisation, respectively. Spirometry graded 458 (10.1%), 1886 (41.7%), 1558 (34.5%), and 616 (13.6%) were GOLD stage I–IV, and 536 (11.4%), 1034 (22.0%), 563 (12.0%), and 2566 (54.6%) were classified as GOLD 2016 Group A–D, respectively, without evident regional variations. Inhaled corticosteroids plus long-acting beta₂-agonist (ICS/LABA, 1316 [26.4%]), ICS/LABA plus long-acting muscarinic antagonist (ICS/LABA + LAMA, 871 [17.5%]), and LAMA (754 [15.1%]) were prescribed at high rates across all groups and regions. Medications not recommended by GOLD were commonly prescribed (TCM, 578 [11.6%]; others, 951 [19.1%]), and 681 (13.7%) were not given ICS or long-acting bronchodilators.

Conclusions

Disease burden among Chinese COPD outpatients is high. Improved guideline adherence for COPD treatment is needed.

Trial registration ClinicalTrials.gov identifier, NCT03131362.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02021-w.

Deep Learning-Based Analytic Models Based on Flow-Volume Curves for Identifying Ventilatory Patterns

Introduction

Spirometry, a pulmonary function test, is being increasingly applied across healthcare tiers, particularly in primary care settings. According to the guidelines set by the American Thoracic Society (ATS) and the European Respiratory Society (ERS), identifying normal, obstructive, restrictive, and mixed ventilatory patterns requires spirometry and lung volume assessments. The aim of the present study was to explore the accuracy of deep learning-based analytic models based on flow–volume curves in identifying the ventilatory patterns. Further, the performance of the best model was compared with that of physicians working in lung function laboratories.

Methods

The gold standard for identifying ventilatory patterns was the rules of ATS/ERS guidelines. One physician chosen from each hospital evaluated the ventilatory patterns according to the international guidelines. Ten deep learning models (ResNet18, ResNet34, ResNet18_vd, ResNet34_vd, ResNet50_vd, ResNet50_vc, SE_ResNet18_vd, VGG11, VGG13, and VGG16) were developed to identify patterns from the flow–volume curves. The patterns obtained by the best-performing model were cross-checked with those obtained by the physicians.

Results

A total of 18,909 subjects were used to develop the models. The ratio of the training, validation, and test sets of the models was 7:2:1. On the test set, the best-performing model VGG13 exhibited an accuracy of 95.6%. Ninety physicians independently interpreted 100 other cases. The average accuracy achieved by the physicians was 76.9 ± 18.4% (interquartile range: 70.5–88.5%) with a moderate agreement (κ = 0.46), physicians from primary care settings achieved a lower accuracy (56.2%), while the VGG13 model accurately identified the ventilatory pattern in 92.0% of the 100 cases (P &lt; 0.0001).

Conclusions

The VGG13 model identified ventilatory patterns with a high accuracy using the flow–volume curves without requiring any other parameter. The model can assist physicians, particularly those in primary care settings, in minimizing errors and variations in ventilatory patterns.

Dynamic changes of pulmonary diffusion capacity in survivors of non-critical COVID-19 during the first six months

BACKGROUND

The dynamic trends of pulmonary function in coronavirus disease 2019 (COVID-19) survivors since discharge have been rarely described. We aimed to describe the changes of lung function and identify risk factors for impaired diffusion capacity.

METHODS

Non-critical COVID-19 patients admitted to the Guangzhou Eighth People's Hospital, China, were enrolled from March to June 2020. Subjects were prospectively followed up with pulmonary function tests at discharge, three and six months after discharge.

FINDINGS

Eighty-six patients completed diffusion capacity tests at three timepoints. The mean diffusion capacity for carbon monoxide (D_LCO)% pred was 79.8% at discharge and significantly improved to 84.9% at Month-3. The transfer coefficient of the lung for carbon monoxide (K_CO)% pred significantly increased from 91.7% at discharge to 95.7% at Month-3. Both of them showed no further improvement at Month-6. The change rates of D_LCO% pred and K_CO% pred were significantly higher in 0-3 months than in 3-6 months. The alveolar ventilation (V_A) improved continuously during the follow-ups. At Month-6, impaired D_LCO% pred was associated with being female (OR 5.2 [1.7-15.8]; p = 0.004) and peak total lesion score (TLS) of chest CT > 8.5 (OR 6.6 [1.7-26.5]; p = 0.007). D_LCO% pred and K_CO% pred were worse in females at discharge. And in patients with impaired diffusion capacity, females' D_LCO% pred recovered slower than males.

INTERPRETATION

The first three months is the critical recovery period for diffusion capacity. The impaired diffusion capacity was more severe and recovered slower in females than in males. Early pulmonary rehabilitation and individualized interventions for recovery are worthy of further investigations.

Clinical characteristics of patients with chronic obstructive pulmonary disease assessed using GOLD 2016 and GOLD 2018 classifications: a cross-sectional study in China

Background

In 2017, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) removed spirometry as a criterion for classifying GOLD risk groups (A–D, low–high risk).

Methods

In this cross-sectional observational study in China, we used the GOLD 2016 (spirometry included) and 2018 (spirometry eliminated) criteria for classifying GOLD risk groups to describe: the proportion of patients with chronic obstructive pulmonary disease (COPD) in each GOLD risk group; disease severity; demographics and comorbidities. Patients aged ≥40 years with a clinical COPD diagnosis for ≥1 year were included. During a single study visit, patients completed the COPD assessment test, modified Medical Research Council (mMRC) dyspnea scale assessment, and spirometry tests. Demographics, medical history, and treatment data were recorded.

Results

In total, 838 patients were included. Most patients were male (86.4%), ≥65 years old (58.6%), and current or former smokers (78.5%). By GOLD 2016, the highest proportion of patients were Group D (42.8%), followed by B (28.2%). By GOLD 2018, the highest proportion of patients were Group B (57.3%), followed by A (25.5%). A total of 296 patients (35.3%) were reclassified, either from Group C to Group A or from Group D to Group B. Overall, 36.2% of patients were receiving treatment concordant with GOLD 2016 recommendations; 34.1% were not receiving any inhaled medication.

Conclusions

The distribution of COPD severity shifted from a high-risk category (by GOLD 2016) to a low-risk category (by GOLD 2018). The high proportion of patients not receiving maintenance medication reflects a high level of under-treatment of the disease.

Trends of pulmonary fungal infections from 2013 to 2019: an AI-based real-world observational study in Guangzhou, China

Recently, the prevalence trend of pulmonary fungal infection (PFI) has rapidly increased. Changes in the risk factors for, distributions of underlying diseases associated with and clinical characteristics of some individual PFIs have been reported in the past decade. However, data regarding PFIs remain uncertain. This study reports the epidemiological characteristics and trends of PFIs over time in recent years. We applied an automated natural language processing (NLP) system to extract clinically relevant information from the electronic health records (EHRs) of PFI patients at the First Affiliated Hospital of Guangzhou Medical University. Then, a trend analysis was performed. From January 1, 2013, to December 31, 2019, 40,504 inpatients and 219,414 outpatients with respiratory diseases were screened, in which 1368 inpatients and 1313 outpatients with PFI were identified. These patients were from throughout the country, but most patients were from southern China. Upward trends in PFIs were observed in both hospitalized patients and outpatients (P<0.05). The stratification by age showed that the incidence of hospitalized patients aged 14–30 years exhibited the most obvious upward trend, increasing from 9.5 per 1000 patients in 2013 to 88.3 per 1000 patients in 2019. Aspergillosis (56.69%) was the most common PFI, but notably, the incidence rates of Talaromyces marneffei, which used to be considered uncommon, exhibited the most rapid increases. In younger PFI patients, the incidence and trend of PFIs have increased. Infection by previously uncommon pathogens has also gradually increased. Increased attention should be paid to young PFI patients and uncommon PFI pathogen infections.

[Comparison of different evaluation systems for assessing disease severity and treatment efficacy in patients with chronic obstructive pulmonary disease]

OBJECTIVE

To compare the practicability and clinical value of different evaluation systems for assessing disease severity and treatment efficacy in patients with chronic obstructive pulmonary disease (COPD).

METHODS

We retrospectively analyzed the clinical data of 28 patients with acute exacerbation of COPD admitted to our hospital between November, 2020 and January, 2021. All the patients were assessed with percentage of predicted forced expiratory volume in 1 second (FEV1% pred), COPD assessment test (CAT), modified British Medical Research Council (mMRC), baseline dyspnea index (BDI), clinical COPD questionnaire (CCQ), St. George's respiratory questionnaire (SGRQ), BODE index, Hamilton Depression Rating Scale (HDRS) at admission and with CAT, mMRC, transition dyspnea index (TDI), CCQ, SGRQ, and HDRS at 1 month after discharge. The correlations among FEV1% pred, CAT, mMRC, BDI, CCQ, SGRQ, BODE and HDRS at admission were analyzed. We also compared the TDI and scores of CAT, mMRC, CCQ, SGRQ, and HDRS at 1 month after discharge among the patients using single (n=8), dual (n=10) or triple inhaled medications (n=10) after discharge.

RESULTS

Among these patients, FEV1% pred was moderately correlated with SGRQ and BDI (r=-0.66, r=0.61; P < 0.01), and CCQ activity score was closely correlated with mMRC, SGRQ activity score and BDI (r=0.82, r=0.92, r=-0.89; P < 0.01). SGRQ activity score was closely correlated with mMRC and BDI (r=0.84, r=-0.91; P < 0.01), and SGRQ symptom score was closely correlated with BODE (r=0.80, P < 0.01). SGRQ impact score was moderately correlated with HDRS (r=0.57, P < 0.01). In all the 28 patients, all the evaluation scores except for CCQ mental score and HDRS improved significantly after treatment (P < 0.05). At 1 month after discharge, CCQ total score decreased significantly in single therapy group (P < 0.05); CAT, mMRC, CCQ and SGRQ improved obviously in dual therapy group (P < 0.05); CCQ and SGRQ scores decreased significantly in triple therapy group (P < 0.05); the TDI did not differ significantly among the 3 groups (P>0.05).

CONCLUSION

For patients with COPD, BDI and TDI are recommended over mMRC for assessing dyspnea. CAT, CCQ and SGRQ allow sensitive assessment of the treatment efficacy to serve as routine evaluation tests, and among them SGRQ is the most comprehensive and is thus recommended when sufficient time is allowed. BODE is relatively complex but highly valuable for predicting the patients'survival outcomes. HDRS is recommended for routine screening of depression in patients with COPD.

Longitudinal virological changes and underlying pathogenesis in hospitalized COVID-19 patients in Guangzhou, China

Prolonged viral RNA shedding and recurrence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in coronavirus disease 2019 (COVID-19) patients have been reported. However, the clinical outcome and pathogenesis remain unclear. In this study, we recruited 43 laboratory-confirmed COVID-19 patients. We found that prolonged viral RNA shedding or recurrence mainly occurred in severe/critical patients (P<0.05). The average viral shedding time in severe/critical patients was more than 50 days, and up to 100 days in some patients, after symptom onset. However, chest computed tomography gradually improved and complete absorption occurred when SARS-CoV-2 RT-PCR was still positive, but specific antibodies appeared. Furthermore, the viral shedding time significantly decreased when the A1,430G or C12,473T mutation occurred (P<0.01 and FDR<0.01) and increased when G227A occurred (P<0.05 and FDR<0.05). High IL1R1, IL1R2, and TNFRSF21 expression in the host positively correlated with viral shedding time (P<0.05 and false discovery rate <0.05). Prolonged viral RNA shedding often occurs but may not increase disease damage. Prolonged viral RNA shedding is associated with viral mutations and host factors.

Changes of quantitative CT-based airway wall dimensions in patients with COVID-19 during early recovery

Background

As the coronavirus disease 19 (COVID-19) pandemic evolves, the need for recognizing the structural pulmonary changes of the disease during early convalescence has emerged. Most studies focus on parenchymal destruction of the disease; but little is known about whether the disease affects the airway. This study was conducted to investigate the changes in airway dimensions and explore the associated factors during early convalescence in patients with COVID-19.

Methods

We retrospectively analyzed quantitative computed tomography (CT)-based airway measures of 69 patients with COVID-19 from 5 February to 17 March 2020, and 32 non-COVID-19 participants from 1 January 2018 to 31 December 2019 from Guangzhou, China. The well-established measures of wall area fraction and the square root of the wall area of a hypothetical bronchus with an inner perimeter of 10 mm, were used to describe airway wall dimensions. We described the characteristics of the dimensions and inner area of airways in 66 patients with COVID-19 at the initial and convalescent stages of the disease, and compared them with the non-COVID-19 group. Linear regression models were constructed to investigate the association of airway dimensions with duration of hospitalization or disease severity after recovery. Partial correlation coefficients were calculated to investigate whether inflammatory markers were related to airway dimensions.

Results

Among 66 patients with COVID-19, airway dimensions were greater during disease initiation than early convalescence, which was significantly greater than in non-COVID-19 participants. No significant difference was found between the patients with COVID-19 at the initial stage and the non-COVID-19 controls regarding the first to eighth generations of the inner area. In adjusted regression models, duration of hospitalization was negatively associated with wall area fraction of the first to the sixth generation of airways. No significant associations exist between airway dimensions and disease severity, or airway dimensions with inflammatory markers.

Conclusions

Airway dimensions in patients with COVID-19 during disease initiation are greater than those in non-COVID-19 participants. Such structural airway changes continue to remain significantly greater during early convalescence. No evidence shows that disease severity or inflammatory markers are associated with airway dimensions, implying that the primary lesion attacked by COVID-19 might not be the airways.

Cardiopulmonary exercise testing might be helpful for interpretation of impaired pulmonary function in recovered COVID-19 patients

We are grateful to have the opportunity for an in-depth discussion with Nusair [1] and D.G. Chapman and co-workers. We sincerely appreciate their insightful comments on our study about the impaired pulmonary function in coronavirus disease 2019 (COVID-19) patients [2, 3], which helps to interpret the parameters of abnormal lung diffusion capacity more accurately.

Besides the impaired lung diffusion capacity, impairment of exercise endurance in recovered patients with COVID-19 should also be consideredhttps://bit.ly/3qrzPDY

Dissociation between airway and systemic autoantibody responses in chronic obstructive pulmonary disease

Background

Autoimmune processes have been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the relationship between airway and systemic autoantibody responses remains unclear. The aim of this study was to elucidate this relationship in patients with stable COPD by investigating the correlation patterns between sputum and serum autoantibodies.

Methods

In this cross-sectional study, sputum supernatant and serum obtained from 47 patients with stable COPD were assayed for the presence of IgG antibodies against ten autoantigens: Smith antigen (Sm), ribosomal phosphoprotein P0 (P0), Ro/Sjögren syndrome type A antigen (Ro/SSA), La/Sjögren syndrome type B antigen (La/SSB), DNA topoisomerase I (Scl-70), histidyl-tRNA synthetase (Jo-1), U1 small nuclear ribonucleoprotein (U1-SnRNP), thyroid peroxidase (TPO), proteinase-3 (PR3), and myeloperoxidase (MPO). A second cohort of 55 stable COPD patients was recruited for validation, and a group of 59 non-COPD controls and a group of 20 connective-tissue disease-associated interstitial lung disease (CTD-ILD) patients were also recruited for comparison. Hierarchical clustering and network analysis were used to evaluate the correlation patterns between sputum and serum autoantibody profiles.

Results

Both hierarchical clustering and network analysis showed that sputum and serum autoantibody profiles were distinct in either analytic COPD cohort or validation cohort. In contrast, the autoantibodies of the two compartments in non-COPD controls and CTD-ILD patients were inadequately distinguished using either hierarchical clustering or network analysis. Many autoantibodies in the sputum were found to have significant correlations with lung function, symptom score and frequency of prior exacerbations in COPD patients, but the antibodies in the serum were not.

Conclusions

We observed a dissociation between sputum autoantibodies and serum autoantibodies in patients with stable COPD, suggesting that airway and systemic immune status may play very different roles in the disease. Sputum autoantibodies are more clinically relevant than serum autoantibodies. Focusing on airway autoimmunity may help improve understanding of the immunopathological mechanism of COPD.

Impaired pulmonary function in discharged patients with COVID-19: more work ahead

Diffusing capacity of the lung for carbon monoxide (D_LCO) reflects the capacity of carbon monoxide transfer from the environment to the pulmonary capillary blood, which is the most clinically useful routine methodology to evaluate the function of the lung to exchange gas. K_CO is the rate constant for carbon monoxide uptake from alveolar gas, which is influenced mostly by the thickness and area of the alveolar capillary membrane, the volume of blood in capillaries supplying ventilated alveoli, and the concentration and properties of haemoglobin in the alveolar capillary blood. D_LCO is mainly determined by K_CO and the alveolar volume (V_A). Mathematically, K_CO can be calculated as D_LCO/V_A under body temperature, ambient pressure, saturated with water vapour conditions [2].

Impairment of diffusion capacity is the most common abnormality in discharged patients with COVID-19. Both decreased alveolar volume and K_CO contribute to the pathogenesis of impaired diffusion capacity. More follow-up work is needed.https://bit.ly/2YL2eaK

Abnormal pulmonary function in COVID-19 patients at time of hospital discharge

On 11 March 2020, the World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) as a pandemic. As of 22 April, more than 2.4 million cases have been confirmed worldwide [1]. In light of the widely documented lung injuries related to COVID-19 [2, 3], concerns have been raised regarding the assessment of lung injury for discharged patients. A recent report portrayed that discharged patients with COVID-19 pneumonia still have residual abnormalities in chest computed tomography (CT) scans, with ground-glass opacity as the most common pattern [4]. Persistent impairment of pulmonary function and exercise capacity have been known to last for months or even years [5–8] in the recovered survivors from other coronavirus pneumonia (severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS)). However, until now, there is no report in regard to pulmonary function in discharged COVID-19 survivors. This article aims to describe the characteristics of pulmonary function in these subjects.

In discharged survivors with COVID-19, impairment of diffusion capacity is the most common abnormality of lung function, followed by restrictive ventilatory defects, which are both associated with the severity of the diseasehttps://bit.ly/2yUaBaT

Sputum and serum autoantibody profiles and their clinical correlation patterns in COPD patients with and without eosinophilic airway inflammation

Background

Autoimmunity plays a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the autoantibody responses and their clinical correlation patterns in COPD patients with and without airway eosinophilic inflammation are unknown. The aim of this study was to compare the autoantibody profiles and their clinical associations in stable COPD patients, stratified by airway inflammatory phenotypes.

Methods

Matched sputum and serum, obtained from 62 stable COPD patients and 14 age-matched controls, were assayed for the presence of IgG and IgM antibodies against 13 autoantigens using protein array. A sputum eosinophil count ≥3% was used as cut-off value to stratify COPD patients into eosinophilic and non-eosinophilic groups. Correlation network analysis was used to evaluate the correlation patterns among autoantibody and clinical variables in each group.

Results

There were no significant differences of clinical parameters and autoantibody levels between the two COPD groups. In non-eosinophilic COPD, sputum anti-CytochromeC_IgG and anti-Aggrecan_IgM were significantly higher than those in healthy controls, and prior exacerbation was positively associated with lung function and sputum anti-Collagen-IV_IgG. While in eosinophilic COPD, sputum/serum anti-heat shock protein (HSP)47_IgG, serum anti-HSP70_IgG and serum anti-Amyloid-beta_IgG were significantly lower than those in healthy controls, and no significant correlation between prior exacerbations and lung function was found. Differences were also observed in network hubs, with the network for non-eosinophilic COPD possessing 9 hubs comprising two lung function parameters and seven autoantibodies, compared with eosinophilic COPD possessing 12 hubs all comprising autoantibodies.

Conclusions

Autoantibody responses were heterogeneous and differentially correlated with the exacerbation risk and other clinical parameters in COPD patients of different inflammatory phenotypes. These findings provide useful insight into the need for personalized management for preventing COPD exacerbations.

A specific subtype of chronic obstructive pulmonary disease classified by forced vital capacity

Background

Forced expiratory volume in one second (FEV₁) is widely used in grading the severity of the airflow limitation observed in chronic obstructive pulmonary disease (COPD). However, the characteristics of COPD classified by forced vital capacity (FVC) remain unknown. Hence, the characteristics of pulmonary function test (PFT) and clinical features of COPD patients classified by FVC were investigated.

Methods

COPD patients were classified into three groups by FVC: (I) large consistent FVC (LC-FVC): before bronchodilator (BBD) and after bronchodilator (ABD) FVC ≥80%pred; (II) inconsistent FVC (I-FVC): BBD FVC <80%pred, while ABD FVC ≥80%pred; (III) small consistent FVC (SC-FVC): BBD and ABD FVC <80%pred. The characteristics of pulmonary function and clinical features of 1,329 retrospective patients and 403 prospective patients were analyzed in different FVC subgroups.

Results

The percentages of LC-FVC, I-FVC and SC-FVC were 25.4%, 13.8% and 60.9%, respectively in the retrospective cohort, and were 34.0%, 15.6%, 50.4%, respectively in the prospective cohort. For the 1,329 retrospective patients, I-FVC showed the best responsiveness to bronchodilator when compared with those of LC-FVC and SC-FVC, no matter evaluated by FEV₁ (0.21 vs. 0.14 vs. 0.10 L, P<0.001) or FVC (0.47 vs. 0.15 vs. 0.23 L, P<0.001), and similar results were found in the 403 prospective patients. Of the 405 retrospective patients who finished lung volume tests, I-FVC and SC-FVC demonstrated higher residual volume than that of LC-FVC (3.43 vs. 3.15 vs. 2.89 L, P<0.05), while I-FVC and LC-FVC showed higher total lung capacity than that of SC-FVC (5.92 vs. 6.06 vs. 5.18 L, P<0.05). In the prospective cohort, LC-FVC and I-FVC experienced more asthma comorbidity than that of SC-FVC (30.7% vs. 30.2% vs. 16.7%, P=0.005); I-FVC group tended to experience more exacerbation events than the other two groups (1.7 vs. 1.2 vs. 1.5, P=0.114).

Conclusions

COPD patients classified by BBD and ABD FVC showed obviously different clinical characteristics, which could assist in distinguishing I-FVC patients who may benefit most from bronchodilators.

Reference values for spirometry in Chinese aged 4-80 years

Background

Although there are over 1.34 billion Chinese in the world, nationwide spirometric reference values for Chinese are unavailable, which is usually based on Caucasian conversion. The aim of this study was to establish spirometric reference values for Chinese with a national wide sample.

Methods

We enrolled healthy non-smokers in 24 centers in Northeast, North, Northwest, Southwest, South, East and Central China from January 2007 to June 2010. Spirometry was performed according to American Thoracic Society and European Respiratory Society guidelines. Reference equations were established using the Lambda-Mu-Sigma (LMS) method for forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), FEV₁/FVC, peak expiratory flow (PEF) and maximal midexpiratory flow (MMEF). Popular Caucasian reference values adjusted with ethnic conversion factors were validated with Chinese measured spirometry data. The present study also compared with other published Chinese equations for spirometry.

Results

A total of 7,115 eligible individuals aged 4 to 80 years (50.9% females) were recruited. Reference equations against age and height by gender were established, including predicted values and lower limits of normal (LLNs). Validated with Chinese data, the mean percentage differences of Caucasian reference values adjusted with ethnic conversion factors were -10.2% to 1.8%, and the percentages of total subjects under LLNs were 0.1% to 8.9%. Compared with this study, the percentage differences of previous Chinese studies ranged from -17.8% to 11.4%, which were found to significantly overestimate or underestimate lung function.

Conclusions

This study established new reference values for better interpretation of spirometry in Chinese aged 4 to 80 years, while Caucasian references with adjustment were inappropriate for Chinese.

Effects of leukotriene D4 nasal challenge on bronchial responsiveness and inflammation in asthmatic patients with allergic rhinitis

BACKGROUND

In asthmatic patients with allergic rhinitis (AR), increased cysteinyl leukotrienes (CysLTs) production in the secretion of nasal mucosa has been associated with greater bronchial hyperresponsiveness (BHR) after nasal allergen challenge. However, the role of CysLTs in eliciting BHR after nasal allergen challenge has not been evaluated. The aim of this study is to evaluate the effect of LTD₄ nasal challenge on BHR and inflammation in asthmatic patients with AR.

METHODS

In this self-controlled study, fifteen eligible consecutively recruited subjects underwent methacholine (Mch) bronchial provocation test before and 30 minutes after LTD₄ nasal provocation test. The cumulative concentration of LTD₄ inducing a 60% increase in nasal airway resistance (PC₆₀NAR) was calculated. The mean values of cumulative doses inducing a 20% decrease in forced expiratory flow in one second (PD₂₀FEV₁) for Mch before and after nasal challenge were compared. Fractional exhaled nitric oxide (FeNO), differential inflammatory cell counts in nasal lavage and induced sputum before and after nasal challenge were compared.

RESULTS

House dust mites were the major allergens accounting for 10/15 (66.7%) of asthmatic patients with AR. The PC₆₀NAR for LT was (8.39±3.48)×10^-3 mg·mL^-1. The PD₂₀FEV₁ before and after nasal challenge was 3.05±3.81 and 2.70±3.81 µmol, respectively (P=0.45). The percentages of eosinophils were (38.36±23.14)% and (45.70±24.86)% in nasal lavage, and (17.51±11.05)% and (24.29±16.52)% in induced sputum before and 24 hours after nasal challenge. The neutrophil counts were (60.64±23.14)% and (53.30±24.46)% in nasal lavage, and (53.83±23.27)% and (56.19±22.28)% in induced sputum before and 24 hours after nasal challenge. The values of FeNO were 40 [35] and 43 [30] ppb before and 24 hours after nasal challenge. No severe adverse effects were reported during the tests.

CONCLUSIONS

Although most asthmatic patients with AR were sensitive to LTD₄ nasal challenge, LTD₄ nasal provocation tests do not confer any major effect on BHR. LTD₄ might not play a vital role in eliciting bronchial responsiveness induced by nasal allergen challenge.

Early COPD patients with lung hyperinflation associated with poorer lung function but better bronchodilator responsiveness

Background

It is unknown whether aggressive medication strategies should be used for early COPD with or without lung hyperinflation. We aimed to explore the characteristics and bronchodilator responsiveness of early COPD patients (stages I and II) with/without lung hyperinflation.

Methods

Four hundred and six patients with COPD who performed both lung volume and bronchodilation tests were retrospectively analyzed. Residual volume to total lung capacity >120% of predicted values indicated lung hyperinflation. The characteristics and bronchodilator responsiveness were compared between the patients with and without lung hyperinflation across all stages of COPD.

Results

The percentages of patients with lung hyperinflation were 72.7% in the entire cohort, 19.4% in stage I, 68.5% in stage II, 95.3% in stage III, and 100.0% in stage IV. The patients with lung hyperinflation exhibited poorer lung function but better bronchodilator responsiveness of both forced expiratory volume in 1 second and forced vital capacity than those without lung hyperinflation during early COPD (t=2.21–5.70, P=0.000–0.029), especially in stage I, while age, body mass index, smoking status, smoking history, and disease duration were similar between the two subgroups in the same stages. From stages I to IV of subgroups with lung hyperinflation, stage I patients had the best bronchodilator responsiveness. Use of bronchodilator responsiveness of forced vital capacity to detect the presence of lung hyperinflation in COPD patients showed relatively high sensitivities (69.5%–75.3%) and specificities (70.3%–75.7%).

Conclusion

We demonstrated the novel finding that early COPD patients with lung hyperinflation are associated with poorer lung function but better bronchodilator responsiveness and established a simple method for detecting lung hyperinflation.

What is the difference between FEV1 change in percentage predicted value and change over baseline in the assessment of bronchodilator responsiveness in patients with COPD?

BACKGROUND

Several criteria are clinically applied in the assessment of significant bronchodilator responsiveness in chronic obstructive pulmonary disease (COPD). The present study aimed to investigate the differences in various degree of severity of COPD among these criteria.

METHODS

After 400 micrograms of salbutamol administered via spacer by metered dose inhaler (MDI), forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) changes (including percentage change, absolute change and absolute change in percentage predicted value) were retrospectively analysed in 933 stable patients with mild-to-very-severe COPD. Significant bronchodilator responsiveness was assessed using American Thoracic Society and European Respiratory Society (ATS-ERS) criterion based on FEV1 or/and FVC (both ≥12% increase over baseline and ≥200 mL) and FEV1 percentage predicted criterion (≥10% absolute increase in percentage predicted FEV1) in different grades of COPD.

RESULTS

Of the patients [age 66.8 years, baseline FEV1 974 mL (39.3% predicted) and FVC 2,242 mL], mean improvements were 126 mL in FEV1 and 265 mL in FVC; 21.4% and 45.3% met ATS-ERS criterion based on FEV1 and FVC, respectively; and 13.5% met FEV1 percentage predicted criterion. The responsive ratios of ATS-ERS criterion based on FEV1 to FEV1 percentage predicted criterion in grade I, II, III and IV of COPD were 0.95(:)1.26(:)2.53(:)6.00, respectively (P<0.01 in grade II and P<0.001 in grade III). As the degree of severity increased, the mean improvement of FEV1 was reduced; on the contrary, that of FVC was increased.

CONCLUSIONS

Compared with FEV1 percentage predicted criterion, ATS-ERS criterion based on FEV1 as well as FVC, the later in particular, detected a larger percentage of patients with significant responsiveness. The increasing difference was relevant as a function of the severity of airflow obstruction.

Preclinical antitumor and antiangiogenic activity of a metronomic schedule of cisplatin against human transitional cell carcinoma (TCC)

e16018

Background: Conventional cisplatin every 3 weeks is frequently precluded in patients with TCC due to renal dysfunction. A metronomic schedule of other chemotherapeutic agents demonstrates anti-angiogenic and anti-tumor activity coupled with better tolerability. A rationale can be made to preclinically evaluate the activity of a metronomic (weekly or 3 days a week) schedule of cisplatin in a preclinical system of TCC. Methods: The activity of cisplatin was assessed in vitro against HUVECs (human umbilical vein endothelial cells). MTT, flow cytometry with Annexin-FITC and scratch assays were employed to assess proliferation, apoptosis and migration, respectively. The activity of cisplatin was evaluated in vivo in murine xenograft models of TCC. The subcutaneous xenografts included 5 × 106 RT4 or 5637 human TCC cells injected into 6- to 8-week-old female athymic BALB/c nu/nu mice. Cisplatin was administered 4 mg/kg IP (intraperitoneal) weekly for up to 6 weeks and compared with untreated mice. Then, 3 groups of tumor-bearing mice received either no therapy, cisplatin 6 mg/kg weekly or cisplatin 2 mg/kg for 3 days a week for up to 6 weeks. Tumor size is measured twice a week. Nephrotoxicity is assessed by serum creatinine and kidney histopathological examination. IHC (immunohistochemistry) of xenografts is performed to measure proliferation (ki-67), apoptosis (cleaved caspase-3) and angiogenesis (CD31). Results: Cisplatin demonstrated significant anti-proliferative, anti-migration and pro-apoptotic activity against HUVECs in vitro. Cisplatin 4 mg/kg weekly inhibited tumor growth, induced higher apoptosis and down-regulated angiogenesis and proliferation in vivo compared to controls. Results from the experiment comparing cisplatin 6 mg/kg weekly with 2 mg/kg 3 days a week (i.e. more metronomic, with potentially more anti-angiogenic and anti-tumor activity and less nephrotoxic) will be presented. Conclusions: A metronomic schedule of cisplatin inhibits tumor growth and demonstrates anti-angiogenic activity in a preclinical model of human TCC. The clinical evaluation of a metronomic schedule of cisplatin may be warranted.

No significant financial relationships to disclose.

Sunitinib malate is active and synergistic with cisplatin against human urothelial carcinoma in a preclinical model

15632

Background: Sunitinib malate is an oral, multitargeted tyrosine kinase inhibitor of VEGFRs, PDGFRs, KIT, RET, and FLT3, approved multinationally for the treatment of advanced RCC and imatinib-resistant or -intolerant GIST. Angiogenesis and plasma VEGF correlate with poor outcomes in human urothelial carcinoma. We designed a preclinical study to examine the efficacy of sunitinib malate alone and in combination with cisplatin against human urothelial carcinoma in vitro and in a murine xenograft model. Methods: The IC50 for sunitinib malate and cisplatin was determined separately against two human urothelial carcinoma cell lines (TCC-SUP and 5637). Sunitinib malate and cisplatin were also applied concurrently to determine activity of the combination. Immunohistochemical staining was performed to detect expression of VEGFR2 on the cell lines, and to measure modulation of this pathway by sunitinib by measuring phosphorylated (p)VEGFR2. Anti-tumor activity of sunitinib malate alone and in combination with cisplatin was determined in a murine xenograft model bearing 5,637 cells. Results: Both human urothelial carcinoma cell lines were found to express VEGFR2. Sunitinib malate displayed significant activity against both urothelial carcinoma cell lines in vitro at low nanomolar concentrations. Furthermore, sunitinib malate in combination with cisplatin was synergistic in vitro. We observed primarily cytostatic activity for sunitinib malate at both 20 mg/kg and 40 mg/kg orally once daily against a murine xenograft model bearing subcutaneous 5,637 cell tumors during 4 weeks of treatment. Anti-tumor activity of sunitinib malate in combination with cisplatin and correlative studies are being evaluated in the murine xenograft model. Conclusion: Sunitinib malate has anti-tumor activity against human urothelial carcinoma as a single agent and is synergistic in combination with cisplatin in vitro. Sunitinib also has significant efficacy in a murine xenograft model of human urothelial carcinoma. These results warrant further exploration of sunitinib malate as a single agent and in combination with cisplatin chemotherapy in human urothelial carcinoma.

No significant financial relationships to disclose.