Open Access Study protocol

The Urban Environment and Childhood Asthma (URECA) birth cohort study: design, methods, and study population

James E Gern1*, Cynthia M Visness2, Peter J Gergen3, Robert A Wood4, Gordon R Bloomberg5, George T O'Connor6, Meyer Kattan7, Hugh A Sampson8, Frank R Witter4, Megan T Sandel6, Wayne G Shreffler8, Rosalind J Wright9, Samuel J Arbes2 and William W Busse1

Author Affiliations

1 University of Wisconsin School of Medicine and Public Health, Madison, WI, USA

2 Rho Federal Systems Division, Inc., Chapel Hill, NC, USA

3 National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA

4 Johns Hopkins University School of Medicine, Baltimore, MD, USA

5 Washington University School of Medicine, St. Louis, MO, USA

6 Boston University School of Medicine, Boston, MA, USA

7 Columbia University College of Physicians and Surgeons, New York, NY, USA

8 Mt. Sinai School of Medicine, New York, NY, USA

9 Channing Laboratory, Brigham and Women's Hospital, Boston, MA, USA

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BMC Pulmonary Medicine 2009, 9:17  doi:10.1186/1471-2466-9-17

Published: 8 May 2009

Abstract

Background

The incidence and morbidity of wheezing illnesses and childhood asthma is especially high in poor urban areas. This paper describes the study design, methods, and population of the Urban Environment and Childhood Asthma (URECA) study, which was established to investigate the immunologic causes of asthma among inner-city children.

Methods and Results

URECA is an observational prospective study that enrolled pregnant women in central urban areas of Baltimore, Boston, New York City, and St. Louis and is following their offspring from birth through age 7 years. The birth cohort consists of 560 inner-city children who have at least one parent with an allergic disease or asthma, and all families live in areas in which at least 20% of the population has incomes below the poverty line. In addition, 49 inner-city children with no parental history of allergies or asthma were enrolled. The primary hypothesis is that specific urban exposures in early life promote a unique pattern of immune development (impaired antiviral and increased Th2 responses) that increases the risk of recurrent wheezing and allergic sensitization in early childhood, and of asthma by age 7 years. To track immune development, cytokine responses of blood mononuclear cells stimulated ex vivo are measured at birth and then annually. Environmental assessments include allergen and endotoxin levels in house dust, pre- and postnatal maternal stress, and indoor air nicotine and nitrogen dioxide. Nasal mucous samples are collected from the children during respiratory illnesses and analyzed for respiratory viruses. The complex interactions between environmental exposures and immune development will be assessed with respect to recurrent wheeze at age 3 years and asthma at age 7 years.

Conclusion

The overall goal of the URECA study is to develop a better understanding of how specific urban exposures affect immune development to promote wheezing illnesses and asthma.