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.

Indoor pet ownership in infancy is a risk factor for the development of sensitization to pets and asthma in childhood

PURPOSE: It is controversial whether indoor pet exposure is either a risk or protective factor developing sensitization to pet allergens or asthma. Therefore, we investigated whether indoor pet ownership entails a risk for the development of asthma and sensitization in childhood. METHODS: The Panel Study of Korean Children (PSKC) is a general-population-based birth cohort study that recruited 2,078 mother-baby dyads in Korea between April and July of 2008. Among 1,577 children who were followed up in 2015, 559 underwent skin prick tests, spirometry and bronchial provocation tests using Provocholine. Having a cat or a dog and the prevalence of asthma were evaluated by using self-reported questionnaires and physicians’ medical records. RESULTS: During infancy, the rate of dog ownership was 4.5% (71 of 1,574) and that of cat ownership was 0.5% (8 of 1,574). Of the subjects, 7.9% (n=109) currently had at least 1 dog and 2.5% (n=34) had at least 1 cat. Pet ownership during infancy was associated with sensitization to cats or dogs (adjusted odds ratio [aOR], 4.24; 95% confidence interval [CI], 1.29–13.98), wheezing within 12 months (aOR, 5.56; 95% CI, 1.65–18.75) and current asthma (wheezing episode in the last 12 months+diagnosed asthma by physicians) (aOR, 6.36; 95% CI, 1.54–26.28). In contrast, pet ownership during the last 12 months was not associated with sensitization to cats or dogs or current asthma. CONCLUSION: Indoor pet exposure during infancy can be critical for developing sensitization to cats or dogs and asthma in childhood. Avoidance of pet exposure in early life may reduce sensitization to cats or dogs and development of asthma.

Prevalence, Risk Factors and Cutoff Values for Bronchial Hyperresponsiveness to Provocholine in 7-Year-Old Children

BACKGROUND: A US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children. METHODS: Six hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated. Skin prick tests, spirometry and bronchial provocation tests for Provocholine as well as a detailed history and physical examinations were performed. The bronchial provocation test was reliably performed on 559 of these children. RESULTS: The prevalence of ever-diagnosed asthma via medical records was 7.7%, and that of current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was 3.2%. The prevalence of BHR to Provocholine was 17.2% and 25.8%, respectively, for a PC20 < 8 and < 16 mg/mL. The risk factors for BHR (PC20 < 16 mg/mL) were atopic dermatitis diagnosis and current dog ownership, whereas those for current asthma were allergy rhinitis diagnosis, a history of bronchiolitis before the age of 3, recent use of analgesics/antipyretics and maternal history of asthma. The BHR prevalence trend showed an increase along with the increased immunoglobulin E (IgE) quartile. The cutoff value of PC20 for the diagnosis of current asthma in children at age 7 was 5.8 mg/mL (sensitivity: 47.1%, specificity: 87.4%). CONCLUSIONS: BHR to Provocholine (PC20 < 8 mg/mL) was observed in 17.2% of 7-year-olds children from the general population and the cutoff value of PC20 for the diagnosis of current asthma was 5.8 mg/mL in this age group. The risk factors for BHR and current asthma showed discrepancies suggesting different underlying mechanisms. Bronchial provocation testing with Provocholine will be a useful clinical tool in the future.

Early Onset Hyperkalemia in Very Low Birth Weight Infants

PURPOSE:This study was designed to know the clinical significance and risk factors of hyperkalemia in very low birth weight infants (VLBWI). METHODS:We compared the incidence of hyperkalemia and its associated ECG abnormalities and mortality rate according to birth weight (102 of less than 1,000 g vs. 328 of 1,000 to 1,500 g) in 430 VLBWI who were born from Jan. 2000 to July 2004, retrospectively, and also compared the several parameter according to serum potassium (35 of hyperkalemia vs. 11 of normokalemia) in 49 selected VLBWI who need mechanical ventilation for respiratory distress without oliguria within 72 hours of life to know the risk factors of hyperkalemia. RESULTS:Overall incidence of hyperkalemia in VLBWI was 21.1%, and was significantly higher in below 1,000 g than in 1,000 to 1,500 g (32.4% vs. 17.7%, P<0.05). Hyperkalemia associated ECG abnormalities, life-threatening cardiac arrhythmia, and death were also significantly higher in below 1,000 g. There were no significant differences in maternal or infant's characteristics, laboratory findings and clinical conditions between hyperkalemic vs. normokalemic group. The incidence of cardiac arrhythmia and mortality rate were also significantly higher in hyperkalemic group. CONCLUSION:Early onset nonoliguric hyperkalemia is often associated with life- threatening cardiac arrhythmia and death in VLBWI, especially less than 1,000 g. Although perinatal risk factors were not found in this study, prospective study is needed to establish the preventive strategy and to improve the outcome.

Hematopoietic Stem Cell Transplantation in Pediatric Acute Myelogenous Leukemia: Relevance of the Stem Cell Source to the Transplant Outcome

BACKGROUND: Postremission therapy is critical for achieving long-term survival in the patients with acute myelogenous leukemia (AML). Allogeneic bone marrow transplantation during the first complete remission (CR) with using a HLA-identical sibling donor may offer the best chance for long-term leukemia-free survival. The patients without matched siblings have several treatment options. The aim of this study was to compare the clinical outcomes after matched sibling transplantation (MST), unrelated stem cell transplantation (non-MST), or autologous peripheral blood stem cell transplantation (APBSCT) as a postremission therapy for children with AML. METHODS: Thirty four hematopoietic stem cell transplantations (SCT) in 32 children with AML were performed between June, 1996 and December, 2004. Two patients who failed at prior APBSCT underwent a 2nd unrelated transplantations. The disease status at the time of transplantation, the conditioning regimen, prophylaxis for graft-versus-host disease (GVHD), the incidence of GVHD, complications, the cause of death, the over-all survival and the event-free survival were retrospectively compared in relation to the stem cell sources. RESULTS: There were 19 males and 13 females with a median age of 8 yr 10 mo. The median follow-up was 17 mo. Twenty-eight cases were transplanted during CR1. Most (5/6) of patients other than the patients who were in CR1 were allocated in the non-MST group. APBSCT was done in 17 cases, and allo-transplants were done in 17 cases, which included MSTs in 10, matched-unrelated BM transplants in 5, haploidentical CD34+selected peripheral blood transplant in 1, and 1-antigen mismatch unrelated cord blood transplantation in 1. Acute GvHD > or = than Grade 2 was found in 20% of the MST cases vs. 85.7% in the non-MST cases (P<.01). The two-year cumulative relapse risks were 46.4% in the APBSCT cases, 20% in the MST cases and 31.5% in the non-MST cases. The Kaplan-Meier 2-year EFS in all cases was 55.7%: 46.3% in the APBMT cases, 80.0% in the MST cases and 68.6% in the non-MST cases, despite the higher proportion of high risk patients in the non-MST group. CONCLUSION: This study indicated that MST was the best option for pediatric AML. For patients without matched siblings, the patients with unrelated transplants fared better, had better survival and a lower relapse rate than the APBSCT patients. However, a further prospective, randomized study that incorporates a larger number of patients and a cord blood transplant arm is necessary to definitely determine the best option for pediatric AML.