María Alvarez

African ancestry and lung function in Puerto Rican children

BACKGROUND Puerto Rican and African American subjects share a significant proportion of African ancestry. Recent findings suggest that African ancestry influences lung function in African American adults. OBJECTIVE We sought to examine whether a greater proportion of African ancestry is associated with lower FEV(1) and forced vital capacity (FVC) in Puerto Rican children independently of socioeconomic status, health care access, or key environmental/lifestyle factors. METHODS We performed a cross-sectional case-control study of 943 Puerto Rican children aged 6 to 14 years with (n= 520) and without (n= 423) asthma (defined as physician-diagnosed asthma and wheeze in the prior year) living in Hartford, Connecticut (n= 383), and San Juan, Puerto Rico (n= 560). We estimated the percentage of African racial ancestry in study participants using genome-wide genotypic data. We tested whether African ancestry is associated with FEV(1) and FVC using linear regression. Multivariate models were adjusted for indicators of socioeconomic status and health care and selected environmental/lifestyle exposures. RESULTS After adjustment for household income and other covariates, each 20% increment in African ancestry was significantly associated with lower prebronchodilator FEV(1) (-105 mL; 95% CI, -159 to -51 mL; P< .001) and FVC (-133 mL; 95% CI, -197 to -69 mL; P< .001) and postbronchodilator FEV(1) (-152 mL; 95% CI, -210 to -94 mL; P< .001) and FVC (-145 mL; 95% CI, -211 to -79 mL; P< .001) in children with asthma. Similar but weaker associations were found for prebronchodilator and postbronchodilator FEV(1) (change for each 20% increment in African ancestry, -78 mL; 95% CI, -131 to -25 mL; P= .004) and for postbronchodilator FVC among children without asthma. CONCLUSIONS Genetic factors, environmental/lifestyle factors, or both correlated with African ancestry might influence childhood lung function in Puerto Rican subjects.

Dengue and hepatic failure

Dengue hemorrhagic fever/dengue shock syndrome is a serious manifestation of dengue fever, which is observed predominantly in the tropical regions of the West Pacific and in Southeast Asia and is associated with secondary infections, mainly in children under age 15. A concomitant microangiopathic coagulopathy has been described; moreover, encephalopathy and even Reyes syndrome have been rarely reported. This report describes a 51-year-old man with secondary dengue infection who presented with clinical evidence of severe hepatitis, encephalopathy, cranial nerve palsy, and microangiopathic coagulopathy and who had a favorable outcome. A careful surveillance for the occurrence of secondary dengue in the Western Hemisphere is proposed, and dengue is suggested as a diagnostic possibility in obscure febrile illnesses presenting as either hepatitis, encephalopathy, or coagulopathy in places in which the mosquito vector, Aedes aegypti, is present.

Prematurity, atopy, and childhood asthma in Puerto Ricans.

BACKGROUND Puerto Rican children share a disproportionate burden of prematurity and asthma in the United States. Little is known about prematurity and childhood asthma in Puerto Rican subjects. OBJECTIVE We sought to examine whether prematurity is associated with asthma in Puerto Rican children. METHODS We performed a case-control study of 678 children aged 6 to 14 years with (n = 351) and without (n = 327) asthma living in San Juan, Puerto Rico. Prematurity was defined by parental report for our primary analysis. In a secondary analysis, we only included children whose parents reported prematurity that required admission to the neonatal intensive care unit. Asthma was defined as physician-diagnosed asthma and wheeze in the prior year. We used logistic regression for analysis. All multivariate models were adjusted for age, sex, household income, atopy (≥1 positive IgE level to common allergens), maternal history of asthma, and early-life exposure to environmental tobacco smoke. RESULTS In a multivariate analysis there was a significant interaction between prematurity and atopy on asthma (P = .006). In an analysis stratified by atopy, prematurity was associated with a nearly 5-fold increased odds of asthma in atopic children (adjusted odds ratio, 4.7; 95% CI, 1.5-14.3; P = .007). In contrast, there was no significant association between prematurity and asthma in nonatopic children. Similar results were obtained in our analysis of prematurity requiring admission to the neonatal intensive care unit and asthma. CONCLUSIONS Our results suggest that atopy modifies the estimated effect of prematurity on asthma in Puerto Rican children. Prematurity might explain, in part, the high prevalence of atopic asthma in this ethnic group.

Stress and Bronchodilator Response in Children with Asthma

RATIONALE Stress is associated with asthma morbidity in Puerto Ricans (PRs), who have reduced bronchodilator response (BDR). OBJECTIVES To examine whether stress and/or a gene regulating anxiety (ADCYAP1R1) is associated with BDR in PR and non-PR children with asthma. METHODS This was a cross-sectional study of stress and BDR (percent change in FEV1 after BD) in 234 PRs ages 9-14 years with asthma. We assessed child stress using the Checklist of Childrens Distress Symptoms, and maternal stress using the Perceived Stress Scale. Replication analyses were conducted in two cohorts. Polymorphisms in ADCYAP1R1 were genotyped in our study and six replication studies. Multivariable models of stress and BDR were adjusted for age, sex, income, environmental tobacco smoke, and use of inhaled corticosteroids. MEASUREMENTS AND MAIN RESULTS High child stress was associated with reduced BDR in three cohorts. PR children who were highly stressed (upper quartile, Checklist of Childrens Distress Symptoms) and whose mothers had high stress (upper quartile, Perceived Stress Scale) had a BDR that was 10.2% (95% confidence interval, 6.1-14.2%) lower than children who had neither high stress nor a highly stressed mother. A polymorphism in ADCYAP1R1 (rs34548976) was associated with reduced BDR. This single-nucleotide polymorphism is associated with reduced expression of the gene for the β2-adrenergic receptor (ADRB2) in CD4(+) lymphocytes of subjects with asthma, and it affects brain connectivity of the amygdala and the insula (a biomarker of anxiety). CONCLUSIONS High child stress and an ADCYAP1R1 single-nucleotide polymorphism are associated with reduced BDR in children with asthma. This is likely caused by down-regulation of ADRB2 in highly stressed children.

Parental Numeracy and Asthma Exacerbations in Puerto Rican Children

BACKGROUND Puerto Ricans share a disproportionate burden of childhood asthma in the United States. Little is known about the impact of low parental numeracy (a health literacy skill) on asthma morbidity in Puerto Rican children. Our objective was to examine whether low parental numeracy is associated with increased asthma morbidity in Puerto Rican children. METHODS This was a cross-sectional study of 351 children with asthma, aged 6 to 14 years, living in San Juan, Puerto Rico. Parents of study participants completed a modified version of the Asthma Numeracy Questionnaire. Multivariate linear or logistic regression was used to examine the relation between low parental numeracy (defined as no correct answers in the modified Asthma Numeracy Questionnaire) and indicators of asthma morbidity (severe asthma exacerbations, core measures of asthma exacerbations, and lung function measures). All multivariate models were adjusted for age, sex, household income, reported use of inhaled corticosteroids in the previous 6 months, and exposure to secondhand tobacco smoke. RESULTS Low parental numeracy was associated with increased odds of visits to the ED or urgent care for asthma (adjusted OR [aOR]=1.7, 95% CI=1.03-2.7, P=.04). The association between low parental numeracy and hospitalizations for asthma was significant only among children not using inhaled corticosteroids (aOR=2.8, 95% CI=1.4-5.6, P=.004). There was no association between low parental numeracy and use of systemic steroids or lung function measures. CONCLUSIONS Low parental numeracy is associated with increased asthma morbidity in Puerto Rican children.

Mouse Allergen, Lung Function, and Atopy in Puerto Rican Children

Objective To examine the relation between mouse allergen exposure and asthma in Puerto Rican children. Methods Mus m 1, Der p 1, Bla g 2, and Fel d 1 allergens were measured in dust samples from homes of Puerto Rican children with (cases) and without (controls) asthma in Hartford, CT (n = 449) and San Juan (SJ), Puerto Rico (n = 678). Linear or logistic regression was used for the multivariate analysis of mouse allergen (Mus m 1) and lung function (FEV1 and FEV1/FVC) and allergy (total IgE and skin test reactivity (STR) to ≥1 allergen) measures. Results Homes in SJ had lower mouse allergen levels than those in Hartford. In multivariate analyses, mouse allergen was associated with higher FEV1 in cases in Hartford (+70.6 ml, 95% confidence interval (CI) = 8.6–132.7 ml, P = 0.03) and SJ (+45.1 ml, 95% CI =  −0.5 to 90.6 ml, P = 0.05). In multivariate analyses of controls, mouse allergen was inversely associated with STR to ≥1 allergen in non-sensitized children (odds ratio [OR] for each log-unit increment in Mus m 1 = 0.7, 95% CI = 0.5–0.9, P<0.01). In a multivariate analysis including all children at both study sites, each log-increment in mouse allergen was positively associated with FEV1 (+28.3 ml, 95% CI = 1.4–55.2 ml, P = 0.04) and inversely associated with STR to ≥1 allergen (OR for each log-unit increment in Mus m 1 = 0.8, 95% CI = 0.6–0.9, P<0.01). Conclusions Mouse allergen is associated with a higher FEV1 and lower odds of STR to ≥1 allergen in Puerto Rican children. This may be explained by the allergen itself or correlated microbial exposures.

Breastfeeding Duration and Asthma in Puerto Rican Children

Little is known about breastfeeding and asthma in Puerto Ricans, the ethnic group most affected by this disease in the US. We examined the relation between the currently recommended duration of breastfeeding and asthma in school‐aged Puerto Rican children.

Genome-wide interaction study of dust mite allergen on lung function in children with asthma

Background: Childhood asthma is likely the result of gene‐by‐environment (G × E) interactions. Dust mite is a known risk factor for asthma morbidity. Yet, there have been no genome‐wide G × E studies of dust mite allergen on asthma‐related phenotypes. Objective: We sought to identify genetic variants whose effects on lung function in children with asthma are modified by the level of dust mite allergen exposure. Methods: A genome‐wide interaction analysis of dust mite allergen level and lung function was performed in a cohort of Puerto Rican children with asthma (Puerto Rico Genetics of Asthma and Lifestyle [PRGOAL]). Replication was attempted in 2 independent cohorts, the Childhood Asthma Management Program (CAMP) and the Genetics of Asthma in Costa Rica Study. Results: Single nucleotide polymorphism (SNP) rs117902240 showed a significant interaction effect on FEV1 with dust mite allergen level in PRGOAL (interaction P = 3.1 × 10−8), and replicated in the same direction in CAMP white children and CAMP Hispanic children (combined interaction P = .0065 for replication cohorts and 7.4 × 10−9 for all cohorts). Rs117902240 was positively associated with FEV1 in children exposed to low dust mite allergen levels, but negatively associated with FEV1 in children exposed to high levels. This SNP is on chromosome 8q24, adjacent to a binding site for CCAAT/enhancer‐binding protein beta, a transcription factor that forms part of the IL‐17 signaling pathway. None of the SNPs identified for FEV1/forced vital capacity replicated in the independent cohorts. Conclusions: Dust mite allergen exposure modifies the estimated effect of rs117902240 on FEV1 in children with asthma. Analysis of existing data suggests that this SNP may have transcription factor regulatory functions. Graphical abstract Figure. No Caption available.