Hye Jin Lee

Bae S, et al. Allergy Asthma Respir Dis. 2025 Jul;13(3):104-113. https://doi.org/10.4168/aard.2025.13.3.104

Impulse oscillometry system (IOS) is a simple, and less invasive method for assessing small to total airway resistance in children. We analyzed the correlation between IOS, spirometry, and plethysmographic parameters performed for the diagnosis of pediatric BO patients. A total of 89 IOS assessments of pediatric BO patients or children without lung disease were included, and the relationship between pulmonary function tests (PFTs) and diagnostic performance was analyzed. R5, R5-20, X5, and AX were statistically significantly worse in the BO group. In general linear correlation analysis, R5% (adjusted β [aβ], -0.59; p < 0.001) and AX % (aβ, -0.9; p < 0.001) showed the strongest correlation with conventional PFT parameters. R5% and AX % also showed the highest correlation with FEF25-75% (aβ, -0.48; p < 0.001 and aβ, -0.83; p < 0.001), and sRaw % (aβ, -0.73; p = 0.003 and aβ, -0.59; p = 0.008, respectively). Multivariate logistic regression analysis showed that R5 Z-score showed the highest ORs with FEV1 (OR = 3.94, p = 0.006), FEF25-75% (OR = 5.96, p = 0.005), and sRaw % (OR = 4.85, p = 0.022). Receiver operating curve analysis suggested AX % and R5% as the most optimal IOS parameters for BO diagnostic performance with the area under the curve of 0.915 and 0.882, respectively. In conclusion, R5 and AX are the parameters that can independently identify the severity of airway obstruction in pediatric BO patients without conventional lung function tests. IOS is an easy-to-perform, and reliable diagnostic method capable of detecting pathological obliteration of the small airways in children with BO.

Background: Leukotriene receptor antagonists (LTRAs) are widely used for asthma and allergic rhinitis (AR), but concerns about the risk of neuropsychiatric events (NPEs) have been raised since the first Drug Safety Communication by the US Food and Drug Administration in 2008. This study evaluates the association between LTRA use and NPEs in children, adolescents and young adults with asthma or AR.Methods: A self-controlled case series study was conducted using the Korean National Health Insurance Service claims database from two 3-year observation periods (observation period 1 (Obs1): 2005–2007; observation period 2 (Obs2): 2016–2018). Asthma or AR patients aged 3–30 years who were prescribed LTRAs and diagnosed with NPEs were included. The incidence rate ratios (IRRs) for the exposed period and risk periods (1–3, 4–7, 8–14, 15–30, 31–90 and >90 days from initiation of LTRA) compared with unexposed periods were calculated using conditional Poisson regression. Subgroup analysis according to age group, type of NPEs and indication of LTRA was performed.Results: Among 17 001 included patients, the risk of NPEs increased in Obs2 (IRR 1.11, 95% CI 1.00–1.22), but did not increase in Obs1. Risk was increased during risk periods 4–7 days (IRR 2.36, 95% CI 1.99–2.76) and 8–14 days (IRR 1.78, 95% CI 1.46–2.15) after initiation of LTRA, particularly in adolescents (IRR 1.28, 95% CI 1.05–1.55) and young adults (IRR 1.14, 95% CI 1.02–1.28), while risk was decreased in children (3–11 years). Risk was not increased for any single type of NPE. AR patients were at increased risk (IRR 1.19, 95% CI 1.01–1.39), but not those with asthma.Conclusions: Overall, risk of NPEs with LTRA use differed between risk periods and subgroups. Physicians should prescribe LTRAs according to indications and inform patients about possible NPEs.

The purpose of this study is to evaluate the quantitative diagnostic performance of computed tomography (CT) densitometry in pediatric patients with bronchiolitis obliterans (BO). We measured the mean lung density (MLD) and represented the difference of MLD in inspiratory and expiratory phases (MLDD), the ratio of the MLD (E/I MLD), and the relative volume percentage of lung density at 50-Hounsfield unit (HU) interval threshold (E600 to E950). We calculated the sensitivity, specificity, and diagnostic accuracy of the lung density indices for the diagnosis of BO. A total of 81 patients, including 51 patients with BO and 30 controls, were included in this study. In the BO patients, expiratory (EXP) MLD and MLDD were significantly lower, and E/I MLD and expiratory low attenuation areas below the threshold of −850 HU to −950 HU (E850, E900, and E950) were statistically significantly higher than controls. Multivariate logistic regression analysis showed that MLDD (odds ratio [OR] = 0.98, p < .001), E/I MLD (OR = 1.39, p < .001), and E850 to E950 were significant densitometry parameters for BO diagnosis. In a receiver-operating characteristic analysis, E900 (cutoff, 1.4%; AUC = 0.920), E/I MLD (cutoff, 0.87; AUC = 0.887), and MLDD (cutoff, 109 HU; AUC = 0.867) showed high accuracy for the diagnosis of BO. In conclusion, the lung CT densitometry can serve as a quantitative marker providing additional indications of expiratory airflow limitation in pediatric patients with BO.

Background: The purpose of this study was to evaluate the quantitative diagnostic performance of computed tomography (CT) densitometry in pediatric bronchiolitis obliterans (BO) patients. Methods: A retrospective chart review was performed on 109 children under age 18 who underwent 3D chest CT from March 2019 to March 2021. We measured the mean lung density (MLD) and calculated the difference of MLD (MLDD) in expiratory and inspiratory phase, the expiratory to inspiratory ratio of mean lung density (E/I MLD), and the relative volume percentage of lung density at 50 HU intervals (E600 to E950). We calculated the sensitivity, specificity, and diagnostic accuracy of lung density indices for the diagnosis of BO. Results: A total of 81 patients, 51 BO patients and 30 controls, were included in this study (mean age: 12.7 vs 11.4 years). Expiratory (EXP) MLD, MLDD, E/I MLD, and E900 were all statistically significantly worse in the BO group. Multivariate logistic regression analysis showed that MLDD (odds ratio [OR] = 0.98, p < .001), E/I MLD (OR = 1.39, p < .001), and E850 (OR = 1.54, p = 0.003) were significant densitometry parameters for BO diagnosis. In ROC analysis, E900 (cut-off 1.4%; AUC = 0.920), E/I MLD (cut-off 0.87; AUC = 0.887), and MLDD (cut-off 109 HU; AUC = 0.867) showed high accuracy in diagnosis of BO. Conclusion: The quantification of lung density with chest CT complements the diagnosis by providing additional indications of expiratory airflow limitation in pediatric BO patients.

This study aimed to evaluate the pretransplant diffusing capacity as a predictor of outcomes in pediatric allogeneic hematopoietic stem cell transplantation (allo-HSCT). Retrospective cohort study of 176 children followed outcomes for 5 years after allo-HSCT. We conducted an analysis of PFTs include spirometry, body plethysmography, and diffusing capacity prior to allo-HSCT. We analyzed the probabilities of overall survival (OS), disease-related mortality (DRM), and non-relapse mortality (NRM). Of all carbon monoxide diffusing capacity (DLCO) parameters obtained using the Global Lung Function Initiative (GLI)-2017, univariate analysis showed that the grade 3, 4 of DLCOadj and Category III, IV of LFS significantly increase NRM (p = 0.003 and p = 0.008). Multivariate analysis indicated that a significant increase in the risk of NRM is associated with grades 3, 4 DLCOadj (hazard ratio [HR] = 4.90, p = 0.020). Kaplan–Meier analyses showed that a significant stepwise increase in NRM was observed with both worse pretransplant DLCOadj grades and LFS categories (p < 0.001 and p = 0.003). A compromised pretransplant diffusing capacity and a high LFS significantly increase the risk of NRM. Especially, DLCOadj before transplantation can be used as an important predictor of NRM after allo-HSCT in children with malignancy.

Background: Functional assessment of small airways in young children with bronchiolitis obliterans (BO) is challenging due to their relative inaccessibility and the generally poor lung function test performance of these patients. We analyze the correlation between impulse oscillometry (IOS), spirometry, and plethysmographic parameters in pediatric BO patients. Methods: A total of 89 IOS assessments of pediatric BO patients or children without lung disease were included, and the relationship between pulmonary function tests (PFTs) and diagnostic performance were analyzed. Results: R5, R5-20, X5, and AX were statistically significantly worse in the BO group. In Spearman’s correlation analysis, AX and R5 showed the strongest correlation with conventional PFT parameters, and AX was the variable with the highest relative correlation with FEV1, FEF25-75%, and both measures of plethysmographic resistance. Receiver operating curve analysis highlighted AX and Raw% pred as the most optimal parameters for BO diagnostic performance with areas under curve of 0.811 and 0.827, respectively. Conclusion: The AX and R5 parameters can be useful in identifying the severity of airway obstruction in children with BO, and IOS more generally can accurately detect pathological obliteration of small airways in pediatric BO patients.

Background: We aimed to assess the use of impulse oscillation system (IOS) parameters to identify patients who have chronic obstructive pulmonary function impairment and to compare IOS and traditional pulmonary function tests (PFTs) for the diagnosis of the obstructive lung disease (OLD) in children. Methods: Total 101 cases were enrolled at the single tertiary medical center between April 2018 and December 2019. Patients with chronic OLD included post infectious bronchiolitis obliterans (BO), BO after HSCT, Swyer-James syndrome, late-onset noninfectious pulmonary complications (LONIPC). Diagnostic performance of IOS parameters to determine indication for patients of FEV1/FVC < 70% was assessed on receiver-operating characteristics (ROC) curve analysis. Results: Out of the 51 patients, 12 patients who were unable to perform conventional PFT, completed the IOS test. On Pearson correlation analysis, FEV1 %pred, FEV1/FVC %, FEF 75%–25% correlated with resistance at 5Hz (R5), R5-R20, R5 %pred, reactance area (Ax) %pred, and reactance at 5Hz (X5). On ROC curve analysis, the area under the curve (AUC) of R5 %pred, R5-R20, Ax absolute value, Ax %pred, X5 were 0.672, 0.728, 0.704, 0.788, 0.649, respectively. Conclusion: IOS parameters showed a good correlation with traditional PFT parameters; reactance parameters, especially Ax showed a stronger correlation than that of the resistance parameters. IOS can be used as an alternative method for pulmonary function assessment in children with chronic OLD with FEV1/FVC < 70%.

Lee HJ, et al. J Korean Med Sci. 2015 Mar;30(3):283-289. http://dx.doi.org/10.3346/jkms.2015.30.3.283