Juan Carlos Ivancevich, MD, in collaboration with Phil Lieberman, MD, conducted these reviews of premier medical journal articles for practicing allergists. Read their top three picks here, and link to the remaining reviews from the menu. You may also visit the Medical Journal Review section of the WAO Web site.

To read translations of past Medical Journal Reviews, click here.

1. Identification of asthma phenotypes (AP) using cluster analysis in the severe asthma research program (SARP).

To identify novel AP using an unsupervised hierarchical cluster analysis of the SARP cohort that includes subjects with persistent asthma, the authors reduced an initial 628 variables to 34 core variables by elimination of redundant data and transformation of categorical variables into ranked ordinal composite variables. They performed a cluster analysis on 726 subjects who met the American Thoracic Society (ATS) definition of severe asthma. Five groups were identified. Cluster 1 (n=110) had early onset atopic asthma with normal lung function treated with ≤ 2 controller medications (82%) and minimal health care utilization. Cluster 2 (n=321) were subjects with early onset atopic asthma and preserved lung function but increased medication requirements (29% on ≥ 3) and health care utilization. Cluster 3 (n=59) was a unique group of mostly older obese women with late onset nonatopic asthma, moderate reductions in FEV1 and frequent oral corticosteroid use. Clusters 4 (n=120) and 5 (n=116) had severe airflow obstruction with bronchodilator responsiveness, but they differed with regards to their ability to attain normal lung function, age of asthma onset, atopic status, and use of oral corticosteroids.
Editor's comment: These data support clinical heterogeneity in asthma and the need for new approaches for the classification of disease severity.
Moore WC, Myers DA, Wenzel SE et al. Identification of Asthma Phenotypes using Cluster Analysis in the Severe Asthma Research Program. American Journal of Respiratory and Critical Care Medicine 2009; published ahead of print on November 5.

Abstract

米国において、喘息の症状や検査所見をコンピュータ解析した結果、5ないし6の独立した疾患群（クラスター）に分かれることが判明した。2群が最も多いIgE-mediated喘息であった。なお、英国やニュージーランドにおいても同様な報告がある(Am J Respir Crit Care Med 2008; 178:218, Eur Respir J 2009; 34:812)

2. The association between allergy skin testing (AST), atopic respiratory conditions (ARC), and stroke mortality in middle-aged and elderly adults.
An analysis was performed of the National Health and Nutrition Examination Survey II Mortality Cohort to determine whether positive AST was associated with an increased risk of fatal stroke and having both positive AST and an ARC was associated with a particularly high risk of stroke-related death. The authors found that patients with positive AST had a hazard ratio for stroke mortality of 1.56 versus those without. Patients with both positive AST and an ARC had a hazard ratio for stroke mortality of 2.31. Individuals with both positive AST and an ARC have more than a 2-fold increased risk of fatal stroke.
Editor's comment: This novel risk factor has substantial implications for a large segment of the population not previously considered at risk.
Matheson EM. Mainous AG, Carnemolla MA. The Association Between Allergy Skin Testing, Atopic Respiratory Conditions, and Stroke Mortality in Middle-Aged and Elderly Adults, The Journal of the American Board of Family Medicine 2009;22(6):604 -609.
Full text

アレルゲン皮膚テスト陽性者は脳卒中死亡リスクが1.56倍、呼吸器症状も合併している場合、リスクは2.31倍であった。

3. Food allergy (FA) among children in the United States.
An analysis of previously published cross-sectional surveys of data on food allergy in children < 18 years of age was performed. Five previously reported surveys were reviewed. In 2007, 3.9% of US children < 18 years of age had reported FA. The prevalence of reported FA increased 18% from 1997 through 2007. In 2005-2006, specific Immunoglobulin E (IgE) to peanut was detectable for 9% of US children. Ambulatory care visits tripled between 1993 and 2006. From 2003 through 2006, there were an estimated average of 317,000 FA-related, ambulatory care visits per year. Hospitalizations with any recorded diagnoses related to FA also increased between 1998-2000 and 2004-2006, from 2,600 to 9,500 discharges per year.
Editor's comment: Food allergy prevalence and/or awareness have increased among US children in recent years.
Branum AM and Lukacs SL. Food Allergy Among Children in the United States, Pediatrics 2009;124(6):1549-1555.
Abstract

2007年における米国の小児の食物アレルギー罹患率は3.9%であり、10年間で18%増加した。食物アレルギーによる入院数も3倍以上増加した。

All 12 reviews are posted in the literature review section of the WAO website.