By Ves Dimov, MD
Allergist / Immunologist
Assistant Professor of Medicine and Pediatrics
University of Chicago
Clustering approach identifies 7 adult asthma phenotypes highly consistent over a 10-year period
This study analyzed longitudinal data (twice, 10 yrs apart) from 3,320 adults with asthma. There were seven asthma phenotypes (prevalence range, 8.4-20.8%), characterized by the level of asthma symptoms (low, moderate, high), the allergic status, and pulmonary function.
Phenotypes observed 10 years apart showed strong similarities. The probability of membership in the same asthma phenotype at both times varied across phenotypes from 54 to 88%. Transitions toward increased asthma symptoms were more frequently observed among nonallergic phenotypes as compared with allergic phenotypes. There was a strong stability of the allergic status over time.
Adult asthma phenotypes identified by a clustering approach, 10 years apart, were highly consistent.
Source: Boudier A, Curjuric I, Basagaña X, Hazgui H, Anto JM et al. Ten-year follow-up of cluster-based asthma phenotypes in adults. A pooled analysis of three cohorts. American Journal of Respiratory and Critical Care Medicine 2013; 188(5): 550-60. (doi:10.1164/rccm.201301-0156OC)
Image source: Asthma, Wikipedia, public domain.
Ipratropium associated with an increased risk of arrhythmias in 12-24-year-old patients with asthma
This study evaluated the risk of arrhythmias associated with inhaled anticholinergic (IAC) use in young patients (5-24 years of age) with asthma between 1997 and 2010. Among 283,429 patients with asthma, 7,656 cases were matched to 76,304 controls (1:10 ratio). Most of the patients were female (58.8%) and 12 years or older (73.3%). Active exposure to inhaled anticholinergic was observed in 0.69% of cases and 0.18% of controls.
Active use was associated with a 1.56-fold increase in arrhythmia risk (adjusted odds ratio [ORadj ] 1.56]). Active high-dose users of IACs (more than 0.114 mg of ipratropium equivalents) had a 69% increase in risk (ORadj 1.69), whereas the added risk for active users receiving low-dose IACs (0.114 mg of ipratropium equivalents or less) was not statistically significant.
Use of ipratropium bromide was associated with an increased risk of arrhythmias in 12-24-year-old patients with asthma.
Source: Adimadhyam S, Schumock GT, Walton S, Joo M, McKell J, Lee TA. Risk of arrhythmias Associated with ipratropium bromide in children, adolescents, and young adults with asthma: A nested case-control study. Pharmacotherapy 2013; Published online before print, 5 August (doi: 10.1002/phar.1336)
Immunological mechanism of asthma remission in children: Allergen-induced CD4+CD25+ T cells are higher in atopic children who outgrew their asthma
This study from Turkey investigated the long-term outcome for children with asthma to determine the risk factors in predicting persistence of disease. It included 62 children with asthma who were evaluated retrospectively at the end of a 10-year follow up (mean age at final assessment was 15.9 years).
50% percent of patients outgrew their asthma during the 10 year follow-up period. All the non-atopic patients outgrew their disease during the study period, whereas 67% of atopic patients did not.
Two risk factors were independently related to the persistence of symptoms: bronchial hyperresponsiveness and rhinitis. Atopic children who were in remission demonstrated significantly higher allergen-induced CD4+CD25+ T cells compared to healthy controls.
Atopy, rhinitis and bronchial hyperreactivity are important risk factors for the persistence of asthma in children. Allergen-induced CD4+CD25+ T cells were higher in the atopic children who outgrew their disease, implicating an immunological mechanism of asthma remission in children.
Source: Aydogan M, Ozen A, Akkoc T, Eifan A, Aktas E et al. Risk factors for persistence of asthma in children: 10 Year Follow-up. Journal of Asthma 2013; Accepted publication, published online before print 6 August. (doi:10.3109/02770903.2013.831872)