Diane Sredl

Low-Normal Gestational Age as a Predictor of Asthma at 6 Years of Age

Background. Perinatal factors, including gestational age and birth weight, influence the development of atopy in early life. However, the role of these factors in the development of asthma in later life among children who do not develop perinatal respiratory disease remains unclear. Methods. Four hundred fifty-four infants who had a history of allergy or asthma in at least 1 parent, were born in the 36th week of gestation or later, and did not develop perinatal respiratory distress were monitored for at least 6 years. Associations between predictor variables and asthma and wheeze were assessed with multivariate logistic regression and repeated-event analyses. Results. Although we previously observed a relationship between low birth weight and persistent wheeze in the first 1 year of life, we did not observe similar associations between low birth weight and asthma at 6 years of age (odds ratio [OR]: 1.05; 95% confidence interval [CI]: 0.40–2.73). However, a strong relationship was found between low-normal gestational age and asthma at 6 years of age (OR: 4.7; 95% CI: 2.1–10.5). The effects of low-normal gestational age were significantly greater among boys than among girls (boys: OR: 8.15; 95% CI: 2.98–22.3; girls: OR: 1.90; 95% CI: 0.38–13.83). Longitudinal analysis of the relationship between gestational age and wheeze during the 6 years of observation confirmed these gender differences. Conclusions. Among children at high risk of developing atopic disease, late prematurity might be an important additional determinant of asthma later in life, and these effects are gender specific.

Mouse exposure and wheeze in the first year of life.

Background Studies have found that exposure to mice is highly prevalent among children with asthma living in urban areas. Objective To examine the relationship between exposure to mice and wheeze in the first year of life. Methods We conducted an ongoing prospective birth cohort study of 498 children with a history of allergy or asthma in at least 1 parent living in metropolitan Boston (the Home Allergens and Asthma Study). Results In a multivariate analysis, infants whose parents reported exposure to mice in the household had nearly twice the odds of developing any wheeze in the first year of life as children without exposure (odds ratio [OR], 1.83; 95% confidence interval [CI], 1.14-2.95; P = .01). Other variables associated with wheeze in the first year of life included low birth weight (OR, 1.77; 95% CI, 1.06-2.95; P = .03), having at least 1 lower respiratory tract illness (OR, 5.59; 95% CI, 3.46-9.04; P P = .01), and exposure to cockroach allergen of 0.05 U/g of dust or more at age 2 to 3 months (OR, 1.83; 95% CI, 1.09-3.08; P = .02). Conclusion Among children with a parental history of asthma or allergies, exposure to mice is associated with wheeze in the first year of life, independent of other factors.

Predictors of indoor exposure to mouse allergen in urban and suburban homes in Boston

Background:  Mouse allergen exposure is prevalent among urban children with asthma. Little is known about mouse allergen exposure in children at risk for the development of allergic diseases.

Elevated allergen-induced IL-13 secretion predicts IgE elevation in children ages 2-5 years.

It is unclear if early immune responses to allergens, specifically Th1 and Th2 cytokine production, predict later immune responses, including increased IgE levels. In a group of children (n = 151) with a parental history of allergy or asthma followed from ages 2 through 5 years, we examined IL-13, IL-4, and IFN-γ secretion by peripheral blood mononuclear cells in response to phytohemagglutinin (PHA), and to dust mite (Der f 1), cockroach (Bla g 2), and cat (Fel d 1) allergens in relation to elevated IgE. Elevated IgE was defined either as a positive IgE-specific response to at least one allergen (dust mite, cockroach, cat, and ovalbumin) or as an elevated total IgE level above a specified cut-off value. In multivariate logistic regression models including 181 observations made between the age of 2 through 5 years and accounting for repeated measures, we found an association between increased IL-13 secretion in response to Der f 1 and elevated IgE (odds ratio [OR] = 1.21, 95% confidence interval [CI] = 1.09–1.34). Age did not modify this relationship. No association was found between allergen-induced IFN-γ secretion and IgE production. Among the group of children with measurements made at age 4–5 (n = 70), IL-13 in response to Der f 1 (p = 0.046), and IL-4 in response to PHA (p = 0.04) were increased among children with elevated IgE. In a smaller subset of children with measurements made at both age 2–3 and age 4–5 (n = 36), IL-13 levels at age 2–3 were also significantly increased in response to Der f 1 (p = 0.01) and Fel d 1 (p = 0.002) among those with elevated IgE at age 4–5. In a group of children ages 2–5 years, there is an association between IL-13 and elevated IgE.