This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The URECA study will be a longitudinal prospective study over a three-year time period, beginning at birth, of the environmental and genetic risk factors for asthma and allergy in urban children. We hypothesize that 1) environmental factors in the inner city adversely influence the development of the immune system to promote cytokine dysregulation, allergy, and recurrent wheezing by age three years and that 2) children who have had a viral lower respiratory infection and have developed cytokine dysregulation by age three years are at increased risk for the development of asthma by age six years. Families with a positive parental history of allergic diseases or asthma will be enrolled prior to birth. Maternal stress and other environmental exposures will be assessed prenatally. Beginning at birth and continuing for the first three years of life, the children will be evaluated longitudinally for blood cell cytokine responses, and for postnatal environmental influences (infections, allergen and microbial exposure, stress, indoor pollutants) that could affect the development of cytokine responses, and for clinical manifestations of allergy and asthma (recurrent wheeze). Finally, DNA will be obtained from study participants and their mothers to evaluate genetic correlates to the observed patterns of immune development as they relate to wheezing diseases and asthma.