The Hispanic health paradox across generations: the relationship of child generational status and citizenship with health outcomes.

OBJECTIVES: In examining the Hispanic health paradox, researchers rarely determine if the paradox persists across immigrant generations. This study examines immigrant respiratory health disparities among Hispanic children in terms of current asthma, bronchitis, and allergies using an expanded six-group immigrant cohort framework that includes citizenship and the fourth-plus generation. STUDY DESIGN: Cross-sectional primary survey data from 1568 caretakers of Hispanic schoolchildren in El Paso, Texas (USA), were utilized. METHODS: Data were analyzed using generalized linear models. RESULTS: Results indicate that a healthy immigrant advantage lasts until the 2.5 generation for bronchitis and allergies (P < 0.05), and until the third generation for asthma (P < 0.10). Citizenship was not an influence on the likelihood of a child having a respiratory health condition. CONCLUSIONS: Findings demonstrate the utility of the expanded six-group cohort framework for examining intergenerational patterns in health conditions among immigrant groups.

Respiratory allergy in immigrants to a highly industrialised area in Italy according to area of origin and time period.

BACKGROUND: Migrants from developing to Western countries tend to become more sensitised to host than to origin country allergens, although substantial changes in migration patterns have occurred in recent decades. METHODS: We investigated adult immigrants with respiratory allergy, first tested for allergic sensitisation between 1985 and 2012 in a highly industrialised area in Italy. A comparison was made of the sensitisation pattern between immigrants and a random sample of native-born subjects affected by a respiratory allergy, and among immigrants according to macro-region of origin and time period. RESULTS: Between 1985 and 2012, 480 immigrants with respiratory allergy had a first positive allergy test. Immigrants were sensitised mainly to grass (67.1%), house dust mites (HDM) (38.5%) and birch (27.5%), with a pattern of sensitisation very similar to that observed in Italians (native-born). An increase in the proportion of subjects with asthma and of subjects with polysensitisation was observed from the first (1985-2002) to the middle (2003-2007) and the most recent period (2008-2012). In recent years, the proportion of subjects with polysensitisation in immigrants is higher than in Italians (native-born) (53.3% vs. 40.1%). Among immigrants, the risk of sensitisation to grass was higher in those from Sub-Saharan Africa (odds ratio, OR=2.76) and Latin America (OR=2.49), whereas risk of sensitisation to HDM was higher among immigrants from South Asia (OR=2.71), compared to immigrants from Eastern Europe. CONCLUSIONS: Immigrants develop multiple sensitisations more frequently than native-born people, and are especially sensitised to local allergens; the country of origin seems to play a role.

Prevalence of allergic sensitization in the United States: results from the National Health and Nutrition Examination Survey (NHANES) 2005-2006.

BACKGROUND: Allergic sensitization is an important risk factor for the development of atopic disease. The National Health and Nutrition Examination Survey (NHANES) 2005-2006 provides the most comprehensive information on IgE-mediated sensitization in the general US population. OBJECTIVE: We investigated clustering, sociodemographic, and regional patterns of allergic sensitization and examined risk factors associated with IgE-mediated sensitization. METHODS: Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Participants aged 1 year or older (n = 9440) were tested for serum specific IgEs (sIgEs) to inhalant and food allergens; participants 6 years or older were tested for 19 sIgEs, and children aged 1 to 5 years were tested for 9 sIgEs. Serum samples were analyzed by using the ImmunoCAP System. Information on demographics and participants' characteristics was collected by means of questionnaire. RESULTS: Of the study population aged 6 years and older, 44.6% had detectable sIgEs, whereas 36.2% of children aged 1 to 5 years were sensitized to 1 or more allergens. Allergen-specific IgEs clustered into 7 groups that might have largely reflected biological cross-reactivity. Although sensitization to individual allergens and allergen types showed regional variation, the overall prevalence of sensitization did not differ across census regions, except in early childhood. In multivariate modeling young age, male sex, non-Hispanic black race/ethnicity, geographic location (census region), and reported pet avoidance measures were most consistently associated with IgE-mediated sensitization. CONCLUSIONS: The overall prevalence of allergic sensitization does not vary across US census regions, except in early life, although allergen-specific sensitization differs based on sociodemographic and regional factors. Biological cross-reactivity might be an important but not the sole contributor to the clustering of allergen-specific IgEs.

Trends in allergic conditions among children: United States, 1997-2011.

Allergic conditions are among the most common medical conditions affecting children in the United States (1-5). An allergic condition is a hypersensitivity disorder in which the immune system reacts to substances in the environment that are normally considered harmless (6,7). Food or digestive allergies, skin allergies (such as eczema), and respiratory allergies (such as hay fever) are the most common allergies among children. Allergies can affect a child's physical and emotional health and can interfere with daily activities, such as sleep, play, and attending school (8,9). A severe allergic reaction with rapid onset, anaphylaxis, can be life threatening. Foods represent the most common cause of anaphylaxis among children and adolescents (10,11). Early detection and appropriate interventions can help to decrease the negative impact of allergies on quality of life (6). This report presents recent trends in the prevalence of allergies and differences by selected sociodemographic characteristics for children under age 18 years.

Mouse to human comparative genetics reveals a novel immunoglobulin E-controlling locus on Hsa8q12.

Atopy is a predisposition to hyperproduction of immunoglobulin E (IgE) against common environmental allergens. It is often associated with development of allergic diseases such as asthma, rhinitis, and dermatitis. Production of IgE is influenced by genetic and environmental factors. In spite of progress in the study of heredity of atopy, the genetic mechanisms of IgE regulation have not yet been completely elucidated. The analysis of complex traits can benefit considerably from integration of human and mouse genetics. Previously, we mapped a mouse IgE-controlling locus Lmr9 on chromosome 4 to a segment of <9 Mb. In this study, we tested levels of total IgE and 25 specific IgEs against inhalant and food allergens in 67 Czech atopic families. In the position homologous to Lmr9 on chromosome 8q12 marked by D8S285, we demonstrated a novel human IgE-controlling locus exhibiting suggestive linkage to composite inhalant allergic sensitization (limit of detection, LOD = 2.11, P = 0.0009) and to nine specific IgEs, with maximum LOD (LOD = 2.42, P = 0.0004) to plantain. We also tested 16 markers at previously reported chromosomal regions of atopy. Linkage to plant allergens exceeding the LOD > 2.0 was detected at 5q33 (D5S1507, LOD = 2.11, P = 0.0009) and 13q14 (D13S165, LOD = 2.74, P = 0.0002). The significant association with plant allergens (quantitative and discrete traits) was found at 7p14 (D7S2250, corrected P = 0.026) and 12q13 (D12S1298, corrected P = 0.043). Thus, the finding of linkage on chromosome 8q12 shows precision and predictive power of mouse models in the investigation of complex traits in humans. Our results also confirm the role of loci at 5q33, 7p14, 12q14, and 13q13 in control of IgE.

Aeroallergen sensitization in healthy children: racial and socioeconomic correlates.

OBJECTIVE: Allergic sensitization is very prevalent and often precedes the development of allergic disease. This study examined the association of race with allergic sensitization among healthy children with no family history of atopy. STUDY DESIGN: Two hundred seventy-five children, predominantly from lower socioeconomic strata, from Cincinnati, Ohio, ages 2 to 18 years without a family or personal history of allergic diseases, underwent skin prick testing to 11 allergen panels. The Pediatric Allergic Disease Quality of Life Questionnaire (PADQLQ) was used to examine the impact of sensitization on quality of life. RESULTS: Thirty-nine percent of healthy children were sensitized to 1 or more allergen panels. Multivariate logistic regression showed increased risk among African-American children for any sensitization (OR, 2.17; [95% CI: 1.23, 3.84]) and sensitization to any outdoor allergen (OR, 2.96 [95% CI: 1.52, 5.74]). Eighty-six percent of children had PADQLQ scores of 1 or less (0 to 6 scale). CONCLUSIONS: Allergic sensitization is prevalent even among children who do not have a personal or family history of asthma, allergic rhinitis, or atopic dermatitis and who have no evidence of current, even subtle effects from this sensitization on allergic disease-related quality of life. African-American children are at greater risk for presence of sensitization, especially to outdoor allergens.

Nitric oxide levels and ciliary beat frequency in indigenous New Zealand children.

New Zealand children's morbidity from respiratory disease is high. This study examines whether subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. A prospective study enrolled a group of healthy children who were screened for respiratory disease by questionnaire and lung function. Skin-prick tests were performed to control for atopy. Exhaled and nasal NO was measured online by a single-breath technique using chemiluminescence. Ciliary specimens were obtained by nasal brushings for assessment of structure and function. The ciliary beat frequency (CBF) (median CBF, 12.5 Hz; range, 10.4-16.8 Hz) and NO values (median exhaled NO, 5.6 ppb; range, 2.3-87.7 ppb; median nasal NO, 403 ppb; range, 34-1,120 ppb) for healthy New Zealand European (n=58), Pacific Island (n=61), and Maori (n=16) children were comparable with levels reported internationally. No ethnic differences in NO, atopy, or CBF were demonstrated. Despite an apparently normal ciliary beat, the percentage of ciliary structural defects was 3 times higher than reported controls (9%; range, 3.6-31.3%), with no difference across ethnic groups. In conclusion, it is unlikely that subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. The high percentage of secondary ciliary defects suggests ongoing environmental or infective damage.

Cumulative incidence of asthma and allergy in north-Norwegian schoolchildren in 1985 and 1995.

The prevalence of asthma and allergy in children is increasing. In order to investigate time trends, follow-up studies conducted several years apart and with identical study designs are essential. We compared two identical, cross-sectional and questionnaire-based studies of asthma and allergy in north-Norwegian schoolchildren (7-13 years of age). The first study was conducted in 1985 (n = 10,093) and the second in 1995 (n = 8,676). The cumulative incidence was as follows: diagnosed asthma, 8.6% in 1995 vs. 5.1% in 1985, relative risk (RR) = 1.71 (95% CI: 1.53-1.90); allergic rhinoconjunctivitis, 22.1% in 1995 vs. 16.4% in 1985, RR = 1.39 (95% CI: 1.31-1.47); and atopic dermatitis, 19.7% in 1995 vs. 13.2% in 1985, RR = 1.48 (95% CI: 1.39-1.58). The cumulative incidence of allergic rhinoconjunctivitis and atopic dermatitis was higher in children of Sami ethnicity than Norse ethnicity in the 1985 study. Furthermore, although not statistically significant, there was a trend towards a greater increase in the cumulative incidence of diagnosed asthma, symptoms of asthma, allergic rhinoconjunctivitis, and atopic dermatitis from 1985 to 1995 in children of Sami ethnicity than Norse ethnicity. We conclude that there has been a marked increase in the cumulative incidence of asthma and allergy prevalence among schoolchildren in northern Norway from 1985 to 1995.

Racial differences in physiologic parameters related to asthma among middle-class children.

BACKGROUND: Asthma morbidity and mortality are higher in the United States for African-American (AA) children when compared to European-American (EA) children. STUDY OBJECTIVES: To explore racial differences in physiologic factors associated with pediatric asthma severity. DESIGN: Cross-sectional. METHODS: We analyzed data from two groups of children in suburban Detroit, one of which contains non-urban, middle-class AA children, a group not usually included in childhood asthma studies. All children were 6 to 8 years of age. Clinical evaluations included medical history, physical examination, skin testing, spirometry, and methacholine challenge. RESULTS: The study population (n = 569) was 14% African American, 51% of the participants were male, and the mean age was 6.8 +/- 0.4 years. Socioeconomic status (parental education) was similar overall by race, although some strata-specific differences were observed. The prevalence of physician-diagnosed asthma was 10% for both AA and EA groups. AA children were more reactive to methacholine than EA children (42% vs 22%, respectively; p = 0.001), and had significantly higher total IgE than EA children (geometric mean, 60. 6 vs 27.5 IU/mL; p = 0.001). Serum IgE was related to methacholine reactivity in EA children (p = 0.001), but not AA children (p = 0. 73). These differences remained after adjustment for gender, age, parental education, parental smoking, and maternal smoking during pregnancy. CONCLUSIONS: Our data support previous reports of racial differences in lung volume, airway responsiveness, and serum IgE concentrations. We found a racial difference in the relationship between total serum IgE and airway responsiveness that is unreported elsewhere. Overall, our results suggest that AA children may be predisposed to asthma.

Year-round housedust mite levels on the Highveld.

OBJECTIVE: To determine the levels of the allergen DerPI, attributable to the house-dust mite (HDM) Dermatophagoides pteronyssinus. DESIGN: A four-season study conducted during 1994/95, sampling mattresses and carpets in the main bedrooms of suburban homes. SETTING: Thirty randomly selected homes in the Edenvale area, occupied by both black and white families living under similar socio-economic conditions in comparable environments. RESULTS: All homes tested positive for the allergen, and in 20% HDM levels exceeded levels recognised as 'safe' in terms of respiratory allergy, i.e. 2 micrograms/g of dust. Once mites were established in a home, they remained for months thereafter. The considerable seasonal variation recorded in HDM levels could not readily be explained. CONCLUSIONS: The HDM is extremely sensitive to minimal variations in microclimate. Its year-round presence is of concern on the Highveld. Infestation levels below 2 micrograms/g of dust, until recently considered the critical point for sensitisation, may be significant triggers of symptoms.

International comparison of the prevalence of asthma symptoms and bronchial hyperresponsiveness.

Potential explanations for the higher rates of asthma mortality and hospital admissions in New Zealand (NZ) include greater prevalence of asthma. To evaluate this further, a large community survey has been undertaken. Rates of respiratory symptoms and bronchial hyperresponsiveness (BHR) for children in Auckland, NZ have been compared to those for children in two locations in New South Wales (NSW), Australia: Wagga Wagga (inland) and Belmont (coastal). The methodology used was the same in both studies: parent-completed questionnaire and BHR measured by response to an abbreviated histamine challenge. In Auckland, 1,084 children participated (84% of those selected) and were compared to 769 inland NSW and 718 coastal NSW children. The prevalence of respiratory symptoms, BHR, severity of BHR, and BHR combined with symptoms was similar among Auckland and inland NSW children but lower among coastal NSW children than those from the other two sites. It is concluded that other unidentified factors must be invoked to explain mortality and admission differences between these regions.