Cord blood versus age 5 mononuclear cell proliferation on IgE and asthma.

BACKGROUND: Fetal immune responses following exposure of mothers to allergens during pregnancy may influence the subsequent risk of childhood asthma. However, the association of allergen-induced cord blood mononuclear cell (CBMC) proliferation and cytokine production with later allergic immune responses and asthma has been controversial. Our objective was to compare indoor allergen-induced CBMC with age 5 peripheral blood mononuclear cell (PBMC) proliferation and determine which may be associated with age 5 allergic immune responses and asthma in an inner city cohort. METHODS: As part of an ongoing cohort study of the Columbia Center for Children's Environmental Health (CCCEH), CBMCs and age 5 PBMCs were cultured with cockroach, mouse, and dust mite protein extracts. CBMC proliferation and cytokine (IL-5 and IFN-gamma) responses, and age 5 PBMC proliferation responses, were compared to anti-cockroach, anti-mouse, and anti-dust mite IgE levels, wheeze, cough, eczema and asthma. RESULTS: Correlations between CBMC and age 5 PBMC proliferation in response to cockroach, mouse, and dust mite antigens were nonsignificant. Cockroach-, mouse-, and dust mite-induced CBMC proliferation and cytokine responses were not associated with allergen-specific IgE at ages 2, 3, and 5, or with asthma and eczema at age 5. However, after adjusting for potential confounders, age 5 cockroach-induced PBMC proliferation was associated with anti-cockroach IgE, total IgE, and asthma (p < 0.05). CONCLUSION: In contrast to allergen-induced CBMC proliferation, age 5 cockroach-induced PBMC proliferation was associated with age 5 specific and total IgE, and asthma, in an inner-city cohort where cockroach allergens are prevalent and exposure can be high.

Anti-cockroach and anti-mouse IgE are associated with early wheeze and atopy in an inner-city birth cohort.

BACKGROUND: The relationships between cockroach and mouse allergen exposure, anti-cockroach and anti-mouse IgE, and wheeze, rhinitis, and atopic dermatitis in children as young as age 3 years are of public health importance but have not been thoroughly evaluated. OBJECTIVE: We hypothesized that inner-city children might have anti-cockroach and anti-mouse IgE by age 3 years, and their presence would be associated with respiratory and atopic symptoms. METHODS: Children were followed prospectively from birth through age 3 years (n = 404). Residential levels of cockroach and mouse allergens, sera levels of anti-cockroach and anti-mouse IgE, and parental report of wheeze, rhinitis, and atopic dermatitis were measured. RESULTS: The odds of early wheeze were significantly higher among children who had IgE to cockroach (odds ratio [OR], 3.3; 95% CI, 1.8-6.2), mouse (OR, 4.6; 95% CI, 2.3-9.0), or both (OR, 9.7; 95% CI, 3.4-27.3). The odds of rhinitis or atopic dermatitis were also higher among children with IgE to cockroach, mouse, or both. Higher IgE class to cockroach and mouse was associated with wheeze and atopic dermatitis (tests for trend, P < .002). CONCLUSIONS: Children age 2 to 3 years who have anti-cockroach and anti-mouse IgE are at increased risk of wheeze and atopy. Moreover, a dose-response relationship was found between higher IgE class and increased prevalence of wheeze, rhinitis, or atopic dermatitis. These findings indicate the importance of reducing exposure to cockroach and mouse allergens for susceptible children.

Effects of winter birth season and prenatal cockroach and mouse allergen exposure on indoor allergen-specific cord blood mononuclear cell proliferation and cytokine production.

BACKGROUND: Season of birth has been associated with the development of atopy and asthma. Relationships among a particular birth season, maternal allergen exposure during the birth season, and childhood development of allergies to allergens in higher concentration during the birth season may be important. OBJECTIVE: To investigate the effects of winter birth (January 1 to March 31) and prenatal cockroach and mouse allergens in settled dust on indoor allergen-specific cord blood mononuclear cell (CBMC) proliferation, TH2 production, and cord blood IgE concentration. METHODS: As part of an ongoing prospective study, 350 cord blood samples were collected. The CBMCs were cultured with cockroach, dust mite, and mouse protein extracts, and proliferation was measured. Interleukin 5, interferon-delta, and total IgE levels were measured. Home dust samples were analyzed for cockroach and mouse allergens. RESULTS: An isolated association was observed between winter birth and a greater mean (SD) cockroach interleukin 5 ratio (winter vs nonwinter birth: 26,043 [11,403] vs 11,344 [3,701]; P = .02). Other associations between winter birth and increased CBMC proliferation, T-helper cytokines, or cord blood IgE levels were not detected. Higher mouse allergen levels were associated with decreased mouse-induced proliferation (winter vs nonwinter birth: mean [SD] stimulation index, 1.72 [0.12] vs 2.02 [0.11]; P = .04). CONCLUSIONS: Winter birth and increased cockroach or mouse allergen levels during pregnancy were not consistently associated with greater CBMC proliferation, T-helper cytokine production, or cord blood IgE levels. Greater indoor allergen exposure during pregnancy does not seem to affect the development of cockroach or mouse immune responses in utero.

Cat ownership is a risk factor for the development of anti-cat IgE but not current wheeze at age 5 years in an inner-city cohort.

BACKGROUND: Cat ownership is inversely associated with atopy and asthma in some areas of the world, but the relevance of cat ownership to allergic disease in the inner city is less known. OBJECTIVE: We sought to evaluate the relationship between cat ownership and the development of early sensitization and wheeze. METHODS: By using a prospective birth cohort study, Dominican and African American mothers living in New York City underwent repeated questionnaires about their child from birth to age 5 years. Sera collected from children at ages 2 (n = 323), 3 (n = 336), and 5 (n = 242) years were assayed for anti-cat IgE and anti-Fel d 1 IgG antibodies. RESULTS: Cat ownership was a significant risk factor for the development of anti-cat IgE by age 2 years (risk ratio [RR], 6.4; 95% CI, 1.9-22) but not for anti-cat IgE development between the ages of 2 and 5 years (RR, 0.88; 95% CI, 0.24-2.3). Current wheeze was significantly more common among those children with anti-cat IgE at ages 3 (RR, 3.5; 95% CI, 2.1-6.0) and 5 (RR, 3.4; 95% CI, 2.3-4.9) years. Cat ownership was inversely associated with current wheeze at age 5 years among children without anti-cat IgE (RR, 0.26; 95% CI, 0.083-0.81). Among children with anti-cat IgE, a similar trend was observed (RR, 0.57; P = .044, Fisher exact test), although one with borderline statistical significance. CONCLUSIONS: Despite a positive association with sensitization, cat ownership in this inner-city cohort was inversely associated with wheeze, potentially suggesting an IgE-independent protective mechanism in this community.