Report on the methacholine bronchial provocation test protocol: An updated statement of Korean Academy of Asthma, Allergy and Clinical Immunology

The Korean Academy of Asthma, Allergy, and Clinical Immunology task force report aims to provide new protocols for methacholine challenge test (MCT). Although new devices have different delivery system compared to old ones, previous protocols are still used, which cannot guarantee adequate diagnoses of asthma. Another important issue is the recent recommendation in European Respiratory Society (ERS) technical standard guideline to use a delivered methacholine dose that causes a 20% decrease in forced expiratory volume in 1 second (FEV1) (PD 20). Although the previous protocol based on the methacholine concentration causing a 20% decrease in FEV1 (PC 20) has been used globally, several studies have reported that PD 20 is more reliable and applicable for new protocols of MCT. Indeed, a tidal breathing inhalation protocol using a breath-actuated or continuous nebulizer is recommended. Herein, we recommend 3 protocols for the MCT using new devices and provide a brief summary of the change in strategy based on the updated ERS guideline.

Development of Prediction Model for Suicide Attempts Using the Korean Youth Health Behavior Web-Based Survey in Korean Middle and High School Students / 신경정신의학

Objectives@#Assessing the risks of youth suicide in educational and clinical settings is crucial.Therefore, this study developed a machine learning model to predict suicide attempts using the Korean Youth Risk Behavior Web-based Survey (KYRBWS). @*Methods@#KYRBWS is conducted annually on Korean middle and high school students to assess their health-related behaviors. The KYRBWS data for 2021, which showed 1206 adolescents reporting suicide attempts out of 54848, was split into the training (n=43878) and test (n=10970) datasets. Thirty-nine features were selected from the KYRBWS questionnaire. The balanced accuracy of the model was employed as a metric to select the best model. Independent validations were conducted with the test dataset of 2021 KYRBWS (n=10970) and the external dataset of 2020 KYRBWS (n=54948). The clinical implication of the prediction by the selected model was measured for sensitivity, specificity, true prediction rate (TPR), and false prediction rate (FPR). @*Results@#Balanced bag of histogram gradient boosting model has shown the best performance (balanced accuracy=0.803). This model shows 76.23% sensitivity, 83.08% specificity, 10.03% TPR, and 99.30% FPR for the test dataset as well as 77.25% sensitivity, 84.62% specificity, 9.31% TPR, and 99.45% FPR for the external dataset, respectively. @*Conclusion@#These results suggest that a specific machine learning model can predict suicide attempts among adolescents with high accuracy.

Impulsivity in Major Depressive Disorder Patients with Suicidal Ideation: Event-related Potentials in a GoNogo Task

Objective@#Suicidal ideation is one of the strongest predictors of suicide, and its relevance to impulsivity in depressed patients has been accumulated. Furthermore, high impulsivity patients show the attenuation of the Nogo amplitude in the GoNogo event-related potential (ERP). The purpose of the current study is to determine the correlation of Nogo ERP to the suicidal ideation depending on the condition of its presence or absence in major depressive disorder (MDD) patients. @*Methods@#A total 162 participants (104 patients with suicidal ideation, 31 patients without suicidal ideation, and 27 healthy controls) were recruited, and performed GoNogo tasks during the electroencephalogram measurement. Depression, anxiety, suicidal ideation and impulsivity were assessed by self-rating scales. The clinical measures, behavioral data and Nogo ERP were compared among groups. @*Results@#The MDD with suicidal ideation (SI) group showed significantly decreased Nogo P3 amplitudes compared to MDD without SI (Fz and Cz electrodes) and control group (all electrodes). The MDD with SI group also had significantly low accuracy of both Go and Nogo trails, compared to the MDD without group. The Nogo P3 amplitudes showed the negative relation to the scores of impulsivity, depression, anxiety and SI. @*Conclusion@#Our results concluded that the Nogo P3 ERP amplitude was decreased in MDD patients with SI compared to MDD patients without SI and controls. These findings suggest that the decreased Nogo P3 amplitude is the one of the candidate biomarker for impulsivity in MDD patients to evaluating SI.

Relationship Between the Loudness Dependence of the Auditory Evoked Potential and the Severity of Suicidal Ideation in Patients with Major Depressive Disorder

Objective@#The loudness dependence of the auditory evoked potential (LDAEP) is a reliable indicator that is inversely related to central serotonergic activity, and recent studies have suggested an association between LDAEP and suicidal ideation. This study investigated differences in LDAEP between patients with major depressive disorder and high suicidality and those with major depressive disorder and low suicidality compared to healthy controls. @*Methods@#This study included 67 participants: 23 patients with major depressive disorder with high suicidality (9 males, mean age 29.3 ± 15.7 years, total score of SSI-BECK ≥ 15), 22 patients with major depressive disorder with low suicidality (9 males, mean age 42.2 ± 14.4 years, total score of SSI-BECK ≤ 14), and 22 healthy controls (11 males, mean age 31.6 ± 8.7 years). Participants completed the following assessments: Patient Health Questionnaire-9, Beck Depression Inventory-II, Beck Scale for Suicidal ideation, State Anxiety Scale of the State-Trait Anxiety Inventory, Beck Anxiety Inventory, and LDAEP (measured at electrode Cz). @*Results@#There were no sex-related differences among groups (p = 0.821). The high-suicidality group exhibited significantly higher LDAEP compared to the low-suicidality group (0.82 ± 0.79 vs. 0.26 ± 0.36, p = 0.014). No significant differences were found between the control and high-suicidality (p = 0.281) or the control and low-suicidality groups (p = 0.236). @*Conclusion@#LDAEP was applied to demonstrate the association between serotonergic activity and suicidal ideation and suicide risk in major depression and may be a candidate of biological marker for preventing suicide in this study.

Relationship Between the Loudness Dependence of the Auditory Evoked Potential and the Severity of Suicidal Ideation in Patients with Major Depressive Disorder

Objective@#The loudness dependence of the auditory evoked potential (LDAEP) is a reliable indicator that is inversely related to central serotonergic activity, and recent studies have suggested an association between LDAEP and suicidal ideation. This study investigated differences in LDAEP between patients with major depressive disorder and high suicidality and those with major depressive disorder and low suicidality compared to healthy controls. @*Methods@#This study included 67 participants: 23 patients with major depressive disorder with high suicidality (9 males, mean age 29.3 ± 15.7 years, total score of SSI-BECK ≥ 15), 22 patients with major depressive disorder with low suicidality (9 males, mean age 42.2 ± 14.4 years, total score of SSI-BECK ≤ 14), and 22 healthy controls (11 males, mean age 31.6 ± 8.7 years). Participants completed the following assessments: Patient Health Questionnaire-9, Beck Depression Inventory-II, Beck Scale for Suicidal ideation, State Anxiety Scale of the State-Trait Anxiety Inventory, Beck Anxiety Inventory, and LDAEP (measured at electrode Cz). @*Results@#There were no sex-related differences among groups (p = 0.821). The high-suicidality group exhibited significantly higher LDAEP compared to the low-suicidality group (0.82 ± 0.79 vs. 0.26 ± 0.36, p = 0.014). No significant differences were found between the control and high-suicidality (p = 0.281) or the control and low-suicidality groups (p = 0.236). @*Conclusion@#LDAEP was applied to demonstrate the association between serotonergic activity and suicidal ideation and suicide risk in major depression and may be a candidate of biological marker for preventing suicide in this study.

Fractional exhaled nitric oxide and forced expiratory volume in 1 second/forced vital capacity have predictive value of asthma exacerbation in Korean school children

BACKGROUND: The incidence of asthma exacerbation (AE) and the predictive value of spirometry and fractional exhaled nitric oxide (FeNO) in school children have not been evaluated.OBJECTIVE: We sought to evaluate the efficacy of spirometry measurement and FeNO monitoring for predicting AE in school children in the Cheongju area in Korea.METHODS: With parental agreement, we studied 170 students aged 7–12 years. Children were evaluated by an asthma specialist using baseline spirometry, skin prick test, seasonal FeNO measurement, and asthma control test. The study participants underwent a physical examination and their medical history was also evaluated by the specialist. They were assessed for asthma control status during regular doctor visits for 1 year.RESULTS: In total, 160 children (94.1%) completed follow-up and FeNO monitoring. Of which, 26 children (16.3%) had AE. AE was associated with male children and children with allergic rhinitis (p < 0.05). While, children with AE tended to have higher FeNO than those without AE, no significant difference was found. The maximum value of FeNO ≥35 ppb was associated with AE (p < 0.05). Children with AE had a significantly decreased baseline forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC), %predicted, forced expiratory flow at 25%–75% of FVC (FEF(25%–75%)). FEV₁/FVC < 80% was associated with AE in children regardless of inhalant allergen sensitization (all p < 0.05).CONCLUSION: Baseline spirometry had a predictive value of AE in school children. Sensitive spirometric parameters such as FEV₁/FVC and FEF(25%–75%) can be used as prognostic factors to predict future childhood AE. FeNO value ≥ 35 ppb during monitoring was associated with AE in school children.

Associated Factors for Asthma Severity in Korean Children: A Korean Childhood Asthma Study

PURPOSE: Childhood asthma has a considerable social impact and economic burden, especially in severe asthma. This study aimed to identify the proportion of childhood asthma severity and to evaluate associated factors for greater asthma severity. METHODS: This study was performed on 667 children aged 5–15 years with asthma from the nationwide 19 hospitals in the Korean childhood Asthma Study (KAS). Asthma was classified as mild intermittent, mild persistent, and moderate/severe persistent groups according to the National Asthma Education and Prevention Program recommendations. Multinomial logistic regression models were used to identify the associated factors for greater asthma severity. RESULTS: Mild persistent asthma was most prevalent (39.0%), followed by mild intermittent (37.6%), moderate persistent (22.8%), and severe persistent asthma (0.6%). Onset later than 6 years of age (adjusted odds ratio [aOR], 1.69 for mild persistent asthma; aOR, 1.92 for moderate/severe persistent asthma) tended to increase asthma severity. Exposure to environmental tobacco smoke (aOR, 1.53 for mild persistent asthma; aOR, 1.85 for moderate/severe persistent asthma), and current dog ownership with sensitization to dog dander (aOR, 5.86 for mild persistent asthma; aOR, 6.90 for moderate/severe persistent asthma) showed increasing trends with greater asthma severity. Lower maternal education levels (aOR, 2.32) and no usage of an air purifier in exposure to high levels of outdoor air pollution (aOR, 1.76) were associated with moderate/severe persistent asthma. CONCLUSIONS: Modification of identified environmental factors associated with greater asthma severity might help better control childhood asthma, thereby reducing the disease burden due to childhood asthma.

Risk Factors and Comorbidities Associated With the Allergic Rhinitis Phenotype in Children According to the ARIA Classification

PURPOSE: Data are lacking on the association between the allergic rhinitis (AR) phenotype and sensitization to specific allergens or bronchial hyperresponsiveness (BHR) in children. We here investigated risk factors and comorbidities, including sensitization to specific allergens and BHR, for the AR phenotype by AR and its Impact on Asthma (ARIA) classification in a general population-based birth cohort study. METHODS: We enrolled 606 children aged 7 years from the Panel Study of Korean Children. The AR phenotype was assigned in accordance with the ARIA classification in children. Skin prick tests and Provocholine provocation test were performed. Risk factors and comorbidities for AR phenotypes were then analyzed. RESULTS: The prevalence of mild and moderate to severe AR in our study cohort was 37.2% and 8.8%, respectively. Recent use of analgesics or antipyretics and current cat ownership were associated with the risk of mild persistent AR. Sensitizations to Dermatophagoides Pteronyssinus (Der p), Japanese hop and cat were associated with moderate to severe persistent AR. Children with moderate to severe AR had a higher risk of current asthma and BHR compared to mild AR cases (adjusted odds ratio [aOR], 5.26; 95% confidence interval [CI], 1.77–15.62). Moderate to severe AR with allergic sensitization was associated with the highest risk of BHR (aOR, 11.77; 95% CI, 3.40–40.74). CONCLUSIONS: Moderate to severe-persistent AR is more closely related to respiratory comorbidities and sensitizations than mild AR. Stratifying the AR phenotype by ARIA classification may assist in disease management.

Age-Related Changes in Auditory Nogo-N200 Latency in Medication-Naïve Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

Objective@#Event-related potential (ERP) changes with brain development in healthy children and adolescents. However, few studies have focused on age-related changes in the N200 and P300 components among individuals with attention-deficit/hyperactivity disorder (ADHD). Therefore, this study aimed to assess age-related differences in the auditory nogo-N200 components in individuals with ADHD. @*Methods@#We enrolled 46 participants with auditory nogo-N200 and nogo-P300 components. We assessed ADHD symptoms using the Advanced Test of Attention (ATA) and Korean ADHD Rating Scale-IV (K-ARS-IV). Moreover, we assessed emotional and behavioral problems using the Korean Child Behavior Checklist (K-CBCL). Further, we measured auditory ERPs. @*Results@#There were no differences with respect to sex or ATA, K-ARS-IV, and K-CBCL scores between the groups. With a 1-year increase in age, the nogo-N200 latency at Fz and Cz decreased by 6.08 ms and 4.88 ms, respectively; this result was statistically significant in multivariable linear regression adjusted by sex and dominant hand. @*Conclusion@#Our findings revealed age-related changes in nogo-N200 latency at the Fz and Cz electrodes in individuals with ADHD. Future studies should perform comparisons with healthy controls to determine whether auditory nogo-N200 can be used to evaluate the developmental level in individuals with ADHD.

Clinical characteristics and cholinesterase levels in childrenwith carbofuran poisoning

Objective@#Acute group poisoning caused by food ingestion occurred in an elementary school in Korea. We aimed todescribe the clinical characteristics, emergency treatment, outcomes, and the cholinesterase level of children with carbofuranpoisoning. @*Methods@#We recruited 32 children who were transferred to hospitals, and they underwent physical examination and laboratoryinvestigations with detailed history-taking performed at one week after carbofuran poisoning. A questionnaireabout presenting symptoms, the transport process, treatment, and the clinical course was conducted with their parent’sagreement. We compared the level of cholinesterase in red blood cells (RBCs) of the child patients without poisoning. @*Results@#The most common presenting symptoms were hypersalivation (84.4%), dizziness (68.8%), nausea (65.6%),and tremor of the limbs (56.3%). Among them, nine children were transported from the initial hospital to a higher levelemergency medical center. Both cholinesterase measurements and atropine injection were done only at a provincialemergency medical center. One child who required ventilator care and was admitted to the intensive care unit showed alow serum cholinesterase level until one week. Six children had symptoms that lasted until a week. Patients showed asignificantly lower RBC cholinesterase level than did the children without poisoning (11974 [95% CI 10257-13997] vs13025 [95% CI 12157-13552] IU/gHb) (P=0.017). @*Conclusion@#The clinical features and cholinesterase activity of children with carbamate poisoning may be different fromthose of adults with carbamate poisoning. RBC acetylcholinestrase was significantly lower than that of healthy childrenuntil a week after carbofuran poisoning. Cholinersterase could be decreased for a long time, against our expectations,and it is a biomarker of exposure to carbofuran in children by serial monitoring.