Assessing post-COVID-19 respiratory dynamics: a comprehensive analysis of pulmonary function, bronchial hyperresponsiveness and bronchodilator response.

Bronchial Hyperresponsiveness and Quality of Life in Asthmatics

Bronchial hyper-responsiveness assessed by the methacholine challenge test (MCT) may aid in the diagnosis of asthma, while a negative MCT can help in excluding the diagnosis. Laboratory measures that predict the results of MCT are expected to reduce the number of procedures. We evaluated the capacity of serum high-sensitivity C-reactive protein (hs-CRP) to predict positive or negative MCT in school-aged children and compared it to a marker of airway inflammation, fractional exhaled nitric oxide (FeNO), and markers of allergic sensitization, immune globulin E (IgE) and peripheral blood eosinophils. Children aged 6-18 years referred for MCT were included in the study. The results of the MCT were compared to hs-CRP levels and FeNO levels, IgE, and peripheral blood eosinophil counts. Of the 131 children assessed, 63 (48 %) patients had positive MCTs (Group I), and 68 (52 %) had negative MCTs (Group II). The best cut-off values to predict a positive MCT by receiver-operating characteristic curves were: 23 ppb for FeNO, 120 IU/mL for IgE, and 500/mL for eosinophils; no cut-off value was found for hs-CRP. The odds ratio for a positive MCT with the above cut-off points were 2.43 (1.05-5.61) for FeNO, 2.4 (1.01-5.74) for IgE, 3.32 (1.13-9.75) for eosinophils, and NS for hs-CRP. No correlation was found between hs-CRP and FeNO, IgE, or eosinophil levels. hs-CRP levels were not helpful, while FeNO, IgE, and eosinophils were useful in the prediction of methacholine bronchial hyper-responsiveness in our group of children.

Methacholine Challenge Methods

Asthma is common in older adults and is confirmed by demonstration of variable expiratory air-flow limitations, typically evaluated by spirometric assessment of bronchodilator responsiveness. However, many patients with clinically suspected asthma and documented air-flow obstruction do not exhibit a post-bronchodilator response that meets or exceeds current established guidelines. We investigated if extending the time from bronchodilator administration to assessment of bronchodilator response increases the yield of spirometry for the diagnosis of asthma in older adults. This was a cross-sectional study. The subjects were non-smokers, ≥ 60y old, and with suspected asthma. Subjects were characterized as (1) those with a positive bronchodilator response on the 30-min post-bronchodilator spirometry, (2) those with a positive bronchodilator response on the 60-min post-bronchodilator spirometry, and (3) those without a positive bronchodilator response but with a positive methacholine challenge test. Factors associated with a late response to bronchodilator were evaluated by using bivariate analysis and by multivariate analysis by using a logistic regression model. This study enrolled 165 subjects. Of these, 81 (49.1%) had a positive bronchodilator response on 30-min post-bronchodilator spirometry; 25 (15.2%) had a positive bronchodilator response on the 1-h post-bronchodilator spirometry; and 59 (35.8%) had no positive bronchodilator response but had a positive methacholine challenge test. On multivariable regression analysis, those with a higher baseline percentage of predicted FEV1, higher scores on a standard asthma control test, and wheezing and/or cough after exercise were more likely to either have a late bronchodilator response or no bronchodilator response. Our study showed that a late positive response to bronchodilator use was more common than previously presumed in older subjects with suspected asthma. Pulmonary function testing laboratories should consider routinely reassessing spirometry at 1 h after bronchodilator use if the earlier assessment did not reveal a significant response.

Introduction. Response to eucapnic voluntary hyperventilation (EVH) has not been compared with methacholine challenge testing (MCCT) in nonathletes being evaluated for dyspnea on exertion. Objective. To determine the airway response to EVH and MCCT in a population of nonathletes who exercise regularly but have symptoms with exertion. Methods. We reviewed records for all patients with exercise symptoms who underwent both EVH and MCCT. Presenting symptoms, comorbid diseases, and results of bronchoprovocation (BP) testing were recorded. This study was approved by the institutional review board at our hospital. Results. A total of 131 patients (mean age 32.3 ± 11.6, body mass index (BMI) 27.1 ± 4.7 kg/m2, 59.5% male) had an EVH, MCCT, and clinical evaluation performed. Overall, 37 (28.2%) patients had positive BP testing and met criteria for exercise-induced bronchoconstriction (EIB). There were 32 (24.4%) patients with a positive EVH, compared with only 11 patients with a positive MCCT (8.4%). There were 26 patients (19.8%) who had a positive EVH but a negative MCCT, and correlation between the two tests was poor to moderate (r = 0.11–0.57). A complaint of chest pain and younger age were independent predictors for a positive EVH, whereas a history of tobacco use and a decreased FEV1/FVC (forced expiratory volume in 1 s/forced vital capacity) predicted a positive MCCT. A previous diagnosis of asthma was an independent predictor for a response to either test. Discussion. In a population of nonathletes who exercise regularly and have symptoms with exertion, EIB is common. Correlation between EVH and MCCT in this population is poor, and although the tests are somewhat complementary, a large percentage of patients had a negative MCCT but a positive EVH. Conclusions. EIB is common in nonathletes with exercise-induced symptoms, and EVH is the preferred test for this population. Clinical implications. EIB is common in nonathletes who exercise regularly. In this population, MCCT will miss most patients with EIB, and MCCT and EVH show only poor-to-moderate correlation. Capsule summary: EVH has not been compared with MCCT in nonathletes without a diagnosis of asthma. Our study shows that the two tests are complementary in this population, but EVH is positive more often.

PurposeThe goal of current study was to introduce noninvasive and reproducible MRI methods for in vivo functional assessment of lung adenocarcinoma (LUAD).MethodsForty-four patients with pathologically confirmed LUAD were included in this study. All the lesions were classified as adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), or invasive adenocarcinoma (IA). The IA lesions were further divided into five subtype patterns, including acinar, lepidic, papillary, micropapillary and solid. Tumors were grouped depending on predominant subtype: low grade (AIS, MIA or lepidic predominant), intermediate grade (papillary or acinar predominant) and high grade (micropapillary, or solid predominant). Spirometry was performed according to American Thoracic Society guidelines. For each patient, Intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) analysis and oxygen-enhanced MRI (OE-MRI) analysis were performed. Spearman’s test was used to assess the relationship between a) whole lung mean percent signal enhancement (PSE) and pulmonary function tests (PFTs) parameters; b) IVIM-derived parameters and PFTs parameters; c) tumor mean PSE and IVIM-derived parameters. Kruskal -Wallis tests were applied to test the difference of tumor mean PSE and IVIM-derived parameters between different histological tumor grades. Receiver operating characteristics (ROC) analysis was used to evaluate the diagnostic performance.ResultsWhole lung mean PSE was significantly positively correlated with PFTs parameters (r = 0.40 ~ 0.44, P < 0.05). f value derived from IVIM-DWI was significantly negatively correlated with PFTs parameters (r = -0.38 ~ -0.47, P < 0.05). Both tumor mean PSE (P = 0.030 < 0.05) and f (P = 0.022 < 0.05) could differentiate different histological grades. f was negatively correlated with tumor mean PSE (r = -0.61, P < 0.001). For the diagnostic performance, the combination of tumor mean PSE and f outperformed than using tumor mean PSE or f alone in both sensitivity and area under the ROC curve.ConclusionsThe combined measurement of OE-MRI and IVIM-DWI may serve as a promising method for the noninvasive and non-radiation evaluation of pulmonary function. Quantitative analyses achieved by OE-MRI and IVIM-DWI offer an approach of the classification of LUAD subtypes.

Lung Function and Airway Hyperresponsiveness in Adult Patients with Sickle Cell Disease

Vocal cord dysfunction in adolescents

Airway hyper-responsiveness (AHR) is a characteristic feature of asthma. The aim of this study was to compare the impulse oscillometry (IOS) and spirometry to methacholine for AHR detection among individuals with clinically hyper-reactive airway disease suggestive of bronchial asthma and baseline spirometry were normal. Adults with symptoms suggestive of AHR and normal baseline spirometry test were selected. The short protocol of methacholine challenge test (MCT) was performed for all subjects using IOS and spirometry simultaneously. The primary endpoint was to compare the methacholine dosage causing a 20% drop in forced expiratory volume in one second (FEV1), with methacholine dosage that causing 40% increasing the baseline respiratory resistance at 5 hertz (R5), as measured by IOS. A total of 235 participants were analyzed, 184 (78.2%) had positive test results with R5, while 81 (34.4%) had positive MCT results with FEV1.The sensitivity and specificity of MCT with R5were 87.3%, 64.6%, and MCT with FEV1 were 39.1%, 85.4%, respectively. The area under the receiver operating characteristic (ROC) curve was greater at lower doses of MCT at R5, (AUROC: 0.653; p= 0.01). The results showed higher sensitivity, negative predictive value, and earlier response of the short protocol of MCT with IOS, compared to MCT with spirometry. Our study suggested the utility of IOS in addition to conventional spirometry as a method of choice in MCT for detection of AHR.

Because of persistent airflow limitation in chronic obstructive pulmonary disease (COPD), patients with COPD often have complications of dyspnea. However, as a leading symptom of COPD, dyspnea in COPD deserves special consideration regarding treatment in this fragile population for pre-clinical health management in COPD. Methods: Based on the above, this paper proposes a multi-modal data combination strategy by combining the local and global features for dyspnea identification in COPD based on the multi-layer perceptron (MLP) classifier. First, lung region images are automatically segmented from chest HRCT images for extracting the original 1,316 lung radiomics (OLR, 1,316) and 13,824 3D CNN features (O3C, 13,824). Second, the local features, including five selected pulmonary function test (PFT) parameters (SLF, 5), 28 selected lung radiomics (SLR, 28), and 22 selected 3D CNN features (S3C, 22), are respectively selected from the original 11 PFT parameters (OLF, 11), 1,316 OLR, and 13,824 O3C by the least absolute shrinkage and selection operator (Lasso) algorithm. Meantime, the global features, including two fused PFT parameters (FLF, 2), six fused lung radiomics (FLR, 6), and 34 fused 3D CNN features (F3C, 34), are respectively fused by 11 OLF, 1,316 OLR, and 13,824 O3C using the principal component analysis (PCA) algorithm. Finally, we combine all the local and global features (SLF + FLF + SLR + FLR + S3C + F3C, 5+ 2 + 28 + 6 + 22 + 34) for dyspnea identification in COPD based on the MLP classifier. Our proposed method comprehensively improves classification performance. The MLP classifier with all the local and global features achieves the best classification performance at 87.7% of accuracy, 87.7% of precision, 87.7% of recall, 87.7% of F1-scorel, and 89.3% of AUC, respectively. Compared with single-modal data, the proposed strategy effectively improves the classification performance for dyspnea identification in COPD, providing an objective and effective tool for COPD management.

Kilpeläinen M, Terho EO, Helenius H, Koskenvuo M. Allergy. 2002;57:1130–1135To examine the relationship between childhood farm environments and allergic sensitization and asthma in young adulthood.The 296 participants were Finnish first-year university students (median age, 21.5 years) recruited by questionnaire. One hundred fifty-two subjects (51%) had a history of asthma or wheezing and 144 (49%) had no history of asthma or wheezing.Physicians in both pulmonary and dermatology subspecialties, who were blinded with respect to original questionnaire data concerning prior symptoms and farm environment, conducted baseline examinations. Pulmonary function tests and methacholine challenge tests were performed. Participants were considered to have current asthma if they had experienced clinical symptoms consistent with asthma, such as wheezing, shortness of breath, or cough associated with typical provoking factors, during the preceding 12 months and the results of methacholine challenge or pulmonary function tests were indicative of asthma. Skin prick tests and allergen-specific immunoglobulin E (IgE) tests with multiple indoor, outdoor, food, and latex allergens were performed. Data were analyzed to examine the effects of childhood farm environments on current asthma and allergic sensitization, with adjustment for early childhood pet ownership.Approximately 10% of subjects experienced childhood farm environments at 0 to 6 years of age, and the incidence of current asthma in the total study population was 10.7%. Significantly fewer patients with histories of farm environments had current asthma, compared with nonfarm participants (odds ratio [OR]: 0.22; 95% confidence interval [CI]: 0.07–0.70). No difference in bronchial hyperreactivity or skin test reactivity between groups was seen, although trends in favor of childhood farm environments were observed, with less bronchial hyperreactivity and fewer positive skin test results in this group. Farm environments had a protective effect on cat-specific IgE (OR: 0.10; 95% CI: 0.02–0.47), and participants in this group were more likely to have dust mite-specific IgE (OR: 3.29; 95% CI: 1.21–8.96).Childhood farm environments were protective against asthma in young adulthood. Sensitization to cat allergens was more likely among participants from nonfarm environments, whereas dust mite sensitivity was more common among those from farm environments.Although this study confirms previously described protective effects of farm environments on the development of asthma and allergic sensitization, results should be interpreted cautiously. The number of patients with a history of childhood farm exposure was small, making it difficult to make generalizations about larger populations with similar environmental histories. In addition, the conflicting findings on the protective effects of farm environments against sensitization to cat and dust mite allergens warrant more investigation.

This study aimed to evaluate the correlation between the %LAV−950 threshold method and a deep learning-based algorithm for emphysema quantification in chest computed tomography (CT) scans with pulmonary function test (PFT) parameters. This retrospective study included 101 chronic obstructive pulmonary disease patients who underwent chest CT and PFTs to assess FEV₁ and carbon monoxide transfer coefficient ( K $_{CO}$ ). Emphysema was quantified using the %LAV−950 method and a deep learning-based algorithm. Quantitative results were obtained from lung and soft tissue reconstruction kernels. Pearson correlation coefficients were calculated to assess associations between CT metrics and PFT parameters. Permutation testing was used to compare correlation coefficients. The %LAV−950 method showed a weak but significant correlation with FEV₁ using soft tissue kernel ( r = −0.281; P = .005), while no significant association was observed with K $_{CO}$ . The deep learning-based method demonstrated stronger and more consistent correlations: a moderate correlation with FEV₁ using lung kernel ( r = −0.303; P = .005), a weak correlation with FEV₁ using soft tissue kernel ( r = −0.289; P = .006), and a moderate correlation with K $_{CO}$ using soft tissue kernel ( r = −0.404; P = .014). Permutation testing confirmed a significant difference in the correlation with K $_{CO}$ between both methods using soft tissue kernel ( r = −0.264; P = .025). The deep learning-based approach demonstrated stronger and more consistent correlations with pulmonary function parameters than the traditional %LAV−950 method, especially for soft tissue kernel reconstructions. These findings highlight its potential to provide a more accurate quantification of emphysema and support its integration into routine CT analysis and artificial intelligence-assisted diagnostic workflows.

Respiratory health concerns in children at some strategic locations from high PM levels during crop residue burning episodes

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Objectives. To assess the prevalence of bronchial hyperresponsiveness (BHR) in a population of north Finland among subjects with no previous diagnosis of asthma or chronic bronchitis by using histamine and methacholine challenges. The agreement between the methods was also evaluated.Study design. An epidemiological study assessing the prevalence of BHR measured with 2 direct dosimetric challenge methods.Methods. Seventy-nine randomly selected subjects (21–73 years) were studied; 67% had respiratory or allergic symptoms. The baseline spirometry was normal or showed mild obstruction. Bronchial challenges to methacholine and histamine were performed on each subject in a randomized order. Provocative doses inducing the decrease of FEV1 by 15% and 2 0% (PD15FEV1 and PD20FEV1) and dose response ratios (DDR) were calculated for both tests.Results. BHR with the methacholine test (PD20FEV1≤2.6 mg) was found in 20% and with the histamine test (PD15FEV1≤1.6 mg) in 28% of subjects; the agreement was 80% (kappa 0.45; 95% CI 0.23–0.68). In staging the severity of BHR the methods had a good agreement (weighted kappa 0.64; CI 95% 0.46-0.82). Prevalence of BHR fulfilling the criteria of the both methods was 14%.Conclusions The findings suggest that the prevalence of BHR in the population of north Finland with no previous diagnosis of asthma or chronic bronchitis is at least 14%, probably around 2 0%, assessed by histamine and methacholine challenge methods. The methods have a good agreement to be used for classifying the severity of BHR.