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1.  Mite, cat, and cockroach exposure, allergen sensitisation, and asthma in children: a case-control study of three schools 
Thorax  1999;54(8):675-680.
BACKGROUND—The amount of allergen necessary to sensitise genetically "at risk" children is unclear. The relation between allergen exposure and asthma is also uncertain.
METHODS—To ensure a wide range of allergen exposures the data from case-control studies of asthma in children aged 12-14 years attending three schools in Los Alamos, New Mexico and Central Virginia were combined. Skin prick tests to indoor and outdoor allergens and bronchial hyperreactivity to histamine were assessed in children with and without symptoms of asthma. The concentration of mite, cat, and cockroach allergens in dust from the children's homes was used as a marker of exposure.
RESULTS—Three hundred and thirty two children (157 with asthmatic symptoms and 175 controls) were investigated. One hundred and eighty three were classified as atopic on the basis of allergen skin prick tests and 68 as asthmatic (symptoms plus bronchial responsiveness). The prevalence and degree of sensitisation to mite and cockroach, but not cat, was strongly associated in atopic children with increasing domestic concentrations of these allergens. Asthma was strongly associated with sensitisation to indoor allergens (p<10-6) and weakly to outdoor allergens (p = 0.026). There was an association between current asthma and the concentration of mite allergen amongst atopic children (p = 0.008) but not amongst those who were specifically mite sensitised (p = 0.16).
CONCLUSIONS—The domestic reservoir concentration of mite and cockroach, but not cat, allergen was closely related to the prevalence of sensitisation in atopic children. However, the prevalence of current asthma had a limited relationship to these allergen measurements, suggesting that other factors play a major part in determining which allergic individuals develop asthma.


PMCID: PMC1745561  PMID: 10413718
2.  Household mold and dust allergens: Exposure, sensitization and childhood asthma morbidity 
Environmental research  2012;118:86-93.
Background
Few studies address concurrent exposures to common household allergens, specific allergen sensitization and childhood asthma morbidity.
Objective
To identify levels of allergen exposures that trigger asthma exacerbations in sensitized individuals.
Methods
We sampled homes for common indoor allergens (fungi, dust mites (Der p 1, Der f 1), cat (Fel d 1), dog (Can f 1) and cockroach (Bla g 1)) for levels associated with respiratory responses among school-aged children with asthma (N=1233) in a month-long study. Blood samples for allergy testing and samples of airborne fungi and settled dust were collected at enrollment. Symptoms and medication use were recorded on calendars. Combined effects of specific allergen sensitization and level of exposure on wheeze, persistent cough, rescue medication use and a 5-level asthma severity score were examined using ordered logistic regression.
Results
Children sensitized and exposed to any Penicillium experienced increased risk of wheeze (odds ratio [OR] 2.12 95% confidence interval [CI] 1.12, 4.04), persistent cough (OR 2.01 95% CI 1.05, 3.85) and higher asthma severity score (OR 1.99 95% CI 1.06, 3.72) compared to those not sensitized or sensitized but unexposed. Children sensitized and exposed to pet allergen were at significantly increased risk of wheeze (by 39% and 53% for Fel d 1 > 0.12 µg/g and Can f 1>1.2 µg/g, respectively). Increased rescue medication use was significantly associated with sensitization and exposure to Der p 1 > 0.10 µg/g (by 47%) and Fel d 1>0.12 µg/g (by 32%).
Conclusion
Asthmatic children sensitized and exposed to low levels of common household allergens Penicillium, Der p 1, Fel d 1 and Can f 1 are at significant risk for increased morbidity.
doi:10.1016/j.envres.2012.07.005
PMCID: PMC3604733  PMID: 22863552
Asthma; Mold; Dust mites; Pet allergens; Wheezing
3.  Socioeconomic predictors of high allergen levels in homes in the greater Boston area. 
Environmental Health Perspectives  2000;108(4):301-307.
In the United States, childhood asthma morbidity and prevalence rates are the highest in less affluent urban minority communities. More than 80% of childhood asthmatics are allergic to one or more inhalant allergens. We evaluated whether socioeconomic status was associated with a differential in the levels and types of indoor home allergens. Dust samples for an ELISA allergen assay were collected from the homes of 499 families as part of a metropolitan Boston, Massachusetts, longitudinal birth cohort study of home allergens and asthma in children with a parental history of asthma or allergy. The proportion of homes with maximum home allergen levels in the highest category was 42% for dust mite allergen (> or = 10 microg/g Der p 1 or Der f 1), 13% for cockroach allergen (> or = 2 U/g Bla g 1 or Bla g 2), 26% for cat allergen (> or = 8 microg/g Fel d 1), and 20% for dog allergen (> or = 10 microg/g Can f 1). Homes in the high-poverty area (> 20% of the population below the poverty level) were more likely to have high cockroach allergen levels than homes in the low-poverty area [51 vs. 3%; OR, 33; 95% confidence interval (CI), 12-90], but less likely to have high levels of dust mite allergen (16 vs. 53%; OR, 0.2; CI, 0.1-0.4). Lower family income, less maternal education, and race/ethnicity (black or Hispanic vs. white) were also associated with a lower risk of high dust mite levels and a greater risk of high cockroach allergen levels. Within a single U.S. metropolitan area we found marked between-community differences in the types of allergens present in the home, but not necessarily in the overall burden of allergen exposure.
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PMCID: PMC1638021  PMID: 10753087
4.  Home Indoor Pollutant Exposures among Inner-City Children With and Without Asthma 
Environmental Health Perspectives  2007;115(11):1665-1669.
Background
Evidence for environmental causes of asthma is limited, especially among African Americans. To look for systematic differences in early life domestic exposures between inner-city preschool children with and without asthma, we performed a study of home indoor air pollutants and allergens.
Methods
Children 2–6 years of age were enrolled in a cohort study in East Baltimore, Maryland. From the child’s bedroom, air was monitored for 3 days for particulate matter ≤ 2.5 and ≤ 10 μm in aerodynamic diameter (PM2.5, PM10), nitrogen dioxide, and ozone. Median baseline values were compared for children with (n = 150) and without (n = 150) asthma. Housing characteristics related to indoor air pollution were assessed by caregiver report and home inspection. In addition, indoor allergen levels were measured in settled dust.
Results
Children were 58% male, 91% African American, and 88% with public health insurance. Housing characteristics related to pollutant exposure and bedroom air pollutant concentrations did not differ significantly between asthmatic and control subjects [median: PM2.5, 28.7 vs. 28.5 μg/m3; PM10, 43.6 vs. 41.4 μg/m3; NO2, 21.6 vs. 20.9 ppb; O3, 1.4 vs. 1.8 ppb; all p > 0.05]. Settled dust allergen levels (cat, dust mite, cockroach, dog, and mouse) were also similar in bedrooms of asthmatic and control children.
Conclusions
Exposures to common home indoor pollutants and allergens are similar for inner-city preschool children with and without asthma. Although these exposures may exacerbate existing asthma, this study does not support a causative role of these factors for risk of developing childhood asthma.
doi:10.1289/ehp.10088
PMCID: PMC2072822  PMID: 18008001
African American; air pollution; allergens; asthma; particulate matter; pediatric; urban
5.  Are Neighborhood-Level Characteristics Associated with Indoor Allergens in the Household? 
Background
Individual home characteristics have been associated with indoor allergen exposure; however, the influence of neighborhood-level characteristics has not been well-studied. We defined neighborhoods as community districts determined by the New York Department of City Planning.
Objective
We examined the relationship between neighborhood-level characteristics and the presence of dust mite (Der f 1), cat (Fel d 1), cockroach (Bla g 2), and mouse (MUP) allergens in the household.
Methods
Using data from the Puerto Rican Asthma Project, a birth cohort of Puerto Rican children at risk of allergic sensitization (n=261) we examined associations between neighborhood characteristics (percent tree canopy, asthma hospitalizations per 1000 children, roadway length within 100 meters of buildings, serious housing code violations per 1000 rental units, poverty rates, and felony crime rates) and the presence of indoor allergens. Allergen cutpoints were used for categorical analyses and defined as follows: dust mite: >0.25 μg/g; cat: >1 μg/g; cockroach: >1 U/g; mouse: >1.6 μg/g.
Results
Serious housing code violations were statistically significantly positively associated with dust mite, cat and mouse allergens (continuous variables), adjusting for mother's income and education, and all neighborhood-level characteristics. In multivariable logistic regression analyses, medium levels of housing code violations were associated with higher dust mite and cat allergens (1.81, 95%CI: 1.08, 3.03 and 3.10, 95%CI: 1.22, 7.92, respectively). A high level of serious housing code violations was associated with higher mouse allergen (2.04, 95%CI: 1.15, 3.62). A medium level of housing code violations was associated with higher cockroach allergen (3.30, 95%CI: 1.11, 9.78).
Conclusions
Neighborhood-level characteristics, specifically housing code violations, appear to be related to indoor allergens, which may have implications for future research explorations and policy decisions.
doi:10.3109/02770900903362676
PMCID: PMC2920139  PMID: 20100024
indoor allergens; dust mite; cat; cockroach; mouse; asthma; neighborhoods; community districts; housing code violations; policy; New York City; Puerto Rican
6.  Environmental tobacco smoke, indoor allergens, and childhood asthma. 
Environmental Health Perspectives  2000;108(Suppl 4):643-651.
Both environmental tobacco smoke and indoor allergens can exacerbate already established childhood albeit primarily through quite disparate mechanisms. In infancy and childhood, environmental tobacco smoke (ETS) exposure is associated with measures of decreased flow in the airways, bronchial hyperresponsiveness, and increased respiratory infections, but the relationship between ETS and allergy is poorly understood. Indoor allergens from dust mite, cockroach, and cat can be associated with asthma exacerbation in children sensitized to the specific allergens. The precise role of either ETS or indoor allergens in the development of asthma is less well understood. The strong and consistent association between ETS and asthma development in young children may relate to both prenatal and postnatal influences on airway caliber or bronchial responsiveness. Dust mite allergen levels predict asthma in children sensitized to dust mite. The tendency to develop specific IgE antibodies to allergens (sensitization) is associated with and may be preceded by the development of a T-helper (Th)2 profile of cytokine release. The importance of either ETS or indoor allergens in the differentiation of T cells into a Th2-type profile of cytokine release or in the localization of immediate-type allergic responses to the lung is unknown. This article evaluates the strength of the evidence that ETS or indoor allergens influence asthma exacerbation and asthma development in children. We also selectively review data for the effectiveness of allergen reduction in reducing asthma symptoms and present a potential research agenda regarding these two broad areas of environmental exposure and their relationship to childhood asthma.
PMCID: PMC1637671  PMID: 10931782
7.  Allergens in Urban Schools and Homes of Children with Asthma 
Background
Most studies of indoor allergens have focused on the home environment. However, schools may be an important site of allergen exposure for children with asthma. We compared school allergen exposure to home exposure in a cohort of children with asthma. Correlations between settled dust and airborne allergen levels in classrooms were examined.
Methods
Settled dust and airborne samples from 12 inner-city schools were analyzed for indoor allergens using multiplex array technology (MARIA). School samples were linked to students with asthma enrolled in the School Inner-City Asthma Study (SICAS). Settled dust samples from students’ bedrooms were analyzed similarly.
Results
From schools, 229 settled dust and 197 airborne samples were obtained. From homes, 118 settled dust samples were obtained. Linear mixed regression models of log-transformed variables showed significantly higher settled dust levels of mouse, cat and dog allergens in schools than homes (545% higher for Mus m 1, estimated absolute difference 0.55 μg/g, p<0.0001; 198% higher for Fel d 1, estimated absolute difference 0.13 μg/g, p=0.0033; and 144% higher for Can f 1, estimated absolute difference 0.05 μg/g, p=0.0008). Airborne and settled dust Mus m 1 levels in classrooms were moderately correlated (r=0.48; p< 0.0001). There were undetectable to very low levels of cockroach and dust mite allergens in both homes and schools.
Conclusions
Mouse allergen levels in schools were substantial. In general, cat and dog allergen levels were low, but detectable, and were higher in schools. Aerosolization of mouse allergen in classrooms may be a significant exposure for students. Further studies are needed to evaluate the effect of indoor allergen exposure in schools on asthma morbidity in students with asthma.
doi:10.1111/j.1399-3038.2012.01327.x
PMCID: PMC3424376  PMID: 22672325
indoor allergens; asthma; inner city; urban; mouse; Mus m 1; Can f 1; Fel d 1; SICAS; school
8.  The indoor environment and inner-city childhood asthma 
Summary
Objective
Exposure to indoor pollutants and allergens has been speculated to cause asthma symptoms and exacerbations and influence the risk of developing asthma. The aim of this article is to review the medical literature regarding the role of the indoor environment on inner-city childhood asthma.
Data sources
A literature search was performed in PubMed. Studies focusing on inner-city indoor allergen, childhood asthma, and environmental controls were included.
Results
The prevalence of asthma in children is increasing especially in inner-city area. Exposure to high levels of indoor allergens and pollutants has been related to asthma development. Studies have shown that mouse, cockroach, pets, dust mite, mold, tobacco smoke, endotoxin and nitrogen dioxide are the important exposures. Recent studies have shown that indoor environmental control is beneficial in reducing asthma morbidity and development.
Conclusions
Inner-city children are exposed to various indoor allergens and pollutants that may lead to asthma development and exacerbation of existing asthma. Multifaceted environmental controls are beneficial in improving asthma symptom and maybe a viable prevention strategy. Further prospective studies of environmental intervention are needed to further identify effective strategies to improve and prevent asthma symptoms in inner-city children.
PMCID: PMC4110514  PMID: 25003723
Indoor environment; allergen; children; asthma; inner-city; air pollution
9.  Neighborhood differences in exposure and sensitization to cockroach, mouse, dust mite, cat and dog allergens in New York City 
Background
Asthma prevalence varies widely among neighborhoods within New York City. Exposure to mouse and cockroach allergens has been suggested as a cause.
Objective
To test the hypotheses that children living in high asthma prevalence neighborhoods (HAPN) would have higher concentrations of cockroach and mouse allergens in their homes than children in low asthma prevalence neighborhoods (LAPN), and that these exposures would be related to sensitization and asthma.
Methods
In the NYC Neighborhood Asthma and Allergy Study, a case-control study of asthma, 7–8 year old children from HAPN (n=120) and LAPN (n=119) were recruited through the same middle-income health insurance plan. Children were classified as asthma cases (n=128) or non-asthma controls (n=111) based on reported symptoms or medication use. Allergens were measured in bed dust.
Results
HAPN homes had higher Bla g 2 (P=0.001), Mus m 1 (P=0.003) and Fel d 1 (P=0.003) and lower Der f 1 (P=0.001) than LAPN homes. Sensitization to indoor allergens was associated with asthma, but relevant allergens differed between LAPN and HAPN. Sensitization to cockroach was more common among HAPN than LAPN children (23.7% vs. 10.8%, P=0.011). Increasing allergen exposure was associated with increased probability of sensitization (IgE) to cockroach (P<0.001), dust mite (P=0.009) and cat (P=0.001), but not mouse (P=0.58) or dog (P=0.85).
Conclusions
These findings further demonstrate the relevance of exposure and sensitization to cockroach and mouse in an urban community and suggest that cockroach allergen exposure could contribute to the higher asthma prevalence observed in some compared with other NYC neighborhoods.
doi:10.1016/j.jaci.2011.02.044
PMCID: PMC3271316  PMID: 21536321
Asthma; Urban; Cockroach; Mouse; Dust mite; Allergy
10.  Early allergen exposure, skin prick responses, and atopic wheeze at age 5 in English children: a cohort study 
Thorax  2004;59(10):855-861.
Background: For many years it has been assumed that the risk of childhood respiratory allergies is related to allergen exposures in early life. There are, however, few prospective data in support. We aimed to examine this relationship in a representative cohort of children born in Ashford, Kent (UK).
Methods: 625 children (94% of those eligible) were followed from birth to the age of 5.5 years at which time 552 underwent skin prick testing to extracts of house dust mite and cat fur allergens. Maternal reports of wheeze in the last year were collected by interview. These outcomes were related to individual domestic concentrations of Der p 1 and Fel d I allergens estimated from dust collection at the age of 8 weeks.
Results: 10% of children were sensitised to house dust mite or cat at age 5.5 years; 7% had atopic wheeze. No significant relationships between allergen exposure and either sensitisation or wheeze were found but, on examination, the exposure-response relationships for both allergens and for each outcome rose steeply at low levels of exposure and were attenuated at high levels of exposure. These patterns were modified by paternal atopy and by birth order.
Conclusions: There are no linear relationships between early allergen exposure and the induction of childhood respiratory allergy; rather, the risks of IgE sensitisation and asthma rise at very low levels of exposure and are attenuated thereafter. These patterns are influenced by parental atopy and birth order. These findings suggest important gene-environment interactions in the development of atopy and asthma and imply that reductions in domestic allergen exposure alone are unlikely to have a major impact in decreasing the incidence of these diseases in childhood.
doi:10.1136/thx.2003.019877
PMCID: PMC1746847  PMID: 15454651
11.  400 Differences in Indoor Allergen Quantification in Hispanic/Latino Children Living in Miami to Those Living in Latin America 
The World Allergy Organization Journal  2012;5(Suppl 2):S144-S145.
Background
Higher levels of indoor allergens can induce in children more susceptiblity to atopy and possibly asthma.
Methods
Indoor allergen sampling was collected by families of allergic children referred to our Allergy clinic. Two groupings were based on location of residence, either locally, Miami Florida (MF), or from Latin America (LA). LA children were from Dominican Republic, Ecuador, Venezuela, or Central America. All MF children were of Hispanic/Latino descent, first or second generation, from similar countries. A dust collection device, (Duststream, Indoor Biotechnologies, Charlottesville) was used to vacuum the bedroom samples. These samples came from the mattress, pillows, floors, rugs, and A/C vents. After collecting, samples were weighed, extracted, vortexed, and incubated. For allergen detection, MARIA (Indoor Biotechnologies) was used to quantify levels of dust mite (DM) allergens, (Dermatophagoides pteronyssinus, Der p 1; Dermatophagoides farinae, Der f 1), and Felis domesticus (Fel d 1), Canis familiaris (Can f 1), Blattella germanica (Bla g 2). Quantification of these allergens was performed on a multiplexing instrument, Luminex 200, (Luminex Corporation, Austin, TX).
Results
Samples from 63 MF and 69 LA were returned. There was a statistical significance in total DM levels between both locations. The mean DM level was 118.7 ng/mL from MF and 241.0 ng/mL from LA (*P > 0.05). Both were in the moderate range for clinical exposure, 2.37 mcg/mL and 4.82 mcg/mL. Contribution of the total DM significance was from the DP species. The mean DP level was 34.1 ng/mL from MF compared to 188.6 ng/mL from LA (**P > 0.001). The clinical exposure of DP was moderate at 3.77 mcg/mL from LA, but in the low range at 0.68 mcg/mL from MF. No significant difference was found in DF between locations, but a minor trend towards more DF exposures in MF rather than LA exists. There was no difference found between locations with the other allergens tested. High cat allergen exposure was found in MF, but with variability and miniscule levels found in LA. Moderate dog and very low cockroach clinical exposures were found in both locations.
Conclusions
Our study reveals intriguing indoor allergen levels based on different environments that may contribute to the epidemiology of allergy/asthma in Hispanic/Latino children.
doi:10.1097/01.WOX.0000412163.39736.a8
PMCID: PMC3512740
12.  Exercise-Induced Bronchospasm and Atopy in Ghana: Two Surveys Ten Years Apart 
PLoS Medicine  2007;4(2):e70.
Background
Asthma and allergic diseases have increased in the developed countries. It is important to determine whether the same trends are occurring in the developing countries in Africa. We aimed to determine the time trend in the prevalence of exercise-induced bronchospasm (EIB) and atopic sensitisation over a ten-year period in Ghanaian schoolchildren.
Methods and Findings
Two surveys conducted using the same methodology ten years apart (1993 and 2003) among schoolchildren aged 9–16 years attending urban rich (UR), urban poor (UP), and rural (R) schools. Exercise provocation consisted of free running for six minutes. Children were skin tested to mite, cat, and dog allergen. 1,095 children were exercised in 1993 and 1,848 in 2003; 916 were skin tested in 1993 and 1,861 in 2003. The prevalence of EIB increased from 3.1% (95% CI 2.2%–4.3%) to 5.2% (4.3%–6.3%); absolute percentage increase 2.1% (95% CI 0.6%–3.5%, p < 0.01); among UR, UP, and R children EIB had approximately doubled from 4.2%, 1.4%, and 2.2% to 8.3%, 3.0% and 3.9% respectively. The prevalence of sensitisation had also doubled from 10.6%, 4.7%, and 4.4% to 20.2%, 10.3%, and 9.9% (UR, UP, and R respectively). Mite sensitisation remained unchanged (5.6% versus 6.4%), but sensitisation to cat and dog increased considerably from 0.7% and 0.3% to 4.6% and 3.1%, respectively. In the multiple logistic regression analysis, sensitisation (odds ratio [OR] 1.77, 95% CI 1.12–2.81), age (OR 0.88, 95% CI 0.79–0.98), school (the risk being was significantly lower in UP and R schools: OR 0.40, 95% CI 0.23–0.68 and OR 0.54, 95% CI 0.34–0.86, respectively) and year of the study (OR 1.73, 95% CI 1.13–2.66) remained significant and independent associates of EIB.
Conclusions
The prevalence of both EIB and sensitisation has approximately doubled over the ten-year period amongst 9- to 16-year-old Ghanaian children irrespective of location, with both EIB and atopy being more common among the UR than the UP and R children.
The prevalence of both exercise-induced bronchospasm and sensitisation has approximately doubled over the ten-year period amongst 9- to 16-year-old Ghanaian children
Editors' Summary
Background.
The proportion of children with asthma is thought to be increasing worldwide, and particularly among children that live in more developed countries. However, it is not clear why this is, since many different aspects of lifestyle and the environment have been linked with the onset of asthma. In Africa, asthma has typically been thought of as being very uncommon, and indeed in many African dialects there is no word for asthma or the symptoms, such as wheezing, that asthmatic children experience. However, some research studies have suggested that asthma might be becoming more common in Africa and that this could be linked to ongoing economic and social changes.
Why Was This Study Done?
The researchers here wanted to understand whether the trend for childhood asthma to be on the increase worldwide was also the case in Africa. Economic growth is bringing about rapid changes in lifestyle in many developing countries, and at the same time the burden of disease is changing. In order to make sure that health systems are appropriately resourced, it's important to anticipate future changes in the burden of different diseases.
What Did the Researchers Do and Find?
This study was based on a comparison between two surveys, carried out ten years apart, of children attending three schools in Ghana's second largest city, Kumasi. The surveys were done in 1993 and 2003, and the schools surveyed were a rich city school, a poor city school, and a school in the nearby countryside. The same methods were used in the two different surveys. Importantly, the researchers used an exercise test as an indicator for asthma, because language differences meant they could not find out whether children were indeed asthmatic. In the exercise test, the schoolchildren ran outdoors for six minutes, and the researchers measured how fast the children could breathe out before and after exercise (their “peak flow”). Children whose drop in peak flow was more than 12.5% were classified as having exercise-induced bronchospasm, which is thought to predict asthma. The children were also tested for their response to extracts that commonly cause allergic reactions, such as from dust mites and cat and dog hair. 1,095 children were studied in 1993 and 1,848 in 2003, paralleling the growth of the city, which also meant that by 2003 the rural school had become incorporated into the city. Over this period of time, the proportion of children with exercise-induced bronchospasm increased in all three schools; overall this proportion went up from 3.1% to 5.2%. Children from the rich city school were most likely to have exercise-induced bronchospasm at either survey date. However, children from the poor city school experienced the biggest change over the time period studied, with more than double the proportion of children having exercise-induced bronchospasm in 2003 as compared to 1993. The researchers also saw similar trends in children who had allergic reactions to common substances.
What Do These Findings Mean?
The researchers observed substantial increases in the rate of exercise-induced bronchospasm, and allergic reactions, between the two survey dates. This finding suggests that asthma is likely to have become much more common in that time. However, exercise-induced bronchospasm is not an exact indicator of asthma so it is not possible to be certain about this. These changes are likely to be linked with the adoption of westernized lifestyles, but which precise factors are responsible for the increase is not clear. Factors linked to the development of asthma include a lower rate of childhood infections, a lower rate of breast-feeding, environmental pollution, and many others. Links between the increase in exercise-induced bronchospasm and any of these factors were not examined in this study. However, these results suggest that if the findings here are common to other African cities as well, a greater proportion of African health budgets will need to be devoted to asthma care in the future.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040070.
Wikipedia has an entry on asthma (Wikipedia is an internet encyclopedia anyone can edit)
The World Health Organization's Ghana minisite has information on this country
Patient information from NHS Direct on asthma
An accompanying PLoS Medicine Essay by Matthias Wjst and Daniel Boakye discusses research on asthma in Africa
doi:10.1371/journal.pmed.0040070
PMCID: PMC1808098  PMID: 17326711
13.  Association of pediatric asthma severity with exposure to common household dust allergens 
Environmental research  2009;109(6):768-774.
Background
Reducingexposure to household dust inhalant allergens has been proposed as one strategy to reduce asthma.
Objective
To examine the dose response relationships and health impact of five common household dust allergens on disease severity, quantified using both symptom frequency and medication use, in atopic and non-atopic asthmatic children.
Methods
Asthmatic children (N=300) aged 4–12 years were followed for one year. Household dust samples from two indoor locations were analyzed for allergens including dust mite (Der p 1, Der f 1), cat (Fel d 1), dog (Can f 1), cockroach (Bla g 1). Daily symptoms and medication use were collected in monthly telephone interviews. Annual disease severity was examined in models including allergens, specific IgE sensitivity and adjusted for age, gender, atopy, ethnicity, and mother’s education.
Results
Der p 1 house dust mite allergen concentration of 2.0 + μg/g from the main room and the child’s bed was related to increased asthma severity independent of allergic status (respectively, OR 2.93, 95% CI 1.37, 6.30 for 2.0 –10.0 μg/g and OR 2.55 95% CI 1.13, 5.73 for ≥ 10.0 μg/g). Higher pet allergen levels were associated with greater asthma severity, but only for those sensitized (cat OR 2.41 95% CI 1.19, 4.89; dog OR 2.06 95% CI 1.01, 4.22).
Conclusion
Higher levels of Der p 1 and pet allergens were associated with asthma severity, but Der p 1 remained an independent risk factor after accounting for pet allergens and regardless of Der p 1 specific IgE status.
doi:10.1016/j.envres.2009.04.010
PMCID: PMC2706291  PMID: 19473655
pediatric asthma; household dust allergens; Der p1; dust mite; pet allergens
14.  Synergism between allergens and viruses and risk of hospital admission with asthma: case-control study 
BMJ : British Medical Journal  2002;324(7340):763.
Objective
To investigate the importance of sensitisation and exposure to allergens and viral infection in precipitating acute asthma in adults resulting in admission to hospital.
Design
Case-control study.
Setting
Large district general hospital.
Participants
60 patients aged 17-50 admitted to hospital over a year with acute asthma, matched with two controls: patients with stable asthma recruited from the outpatient department and patients admitted to hospital with non-respiratory conditions (inpatient controls).
Main outcome measures
Atopic status (skin testing and total and specific IgE), presence of common respiratory viruses and atypical bacteria (polymerase chain reaction), dust samples from homes, and exposure to allergens (enzyme linked immunosorbent assay (ELISA): Der p 1, Fel d 1, Can f 1, and Bla g 2).
Results
Viruses were detected in 31 of 177 patients. The difference in the frequency of viruses detected between the groups was significant (admitted with asthma 26%, stable asthma 18%, inpatient controls 9%; P=0.04). A significantly higher proportion of patients admitted with asthma (66%) were sensitised and exposed to either mite, cat, or dog allergen than patients with stable asthma (37%) and inpatient controls (15%; P<0.001). Being sensitised and exposed to allergens was an independent associate of the group admitted to hospital (odds ratio 2.3, 95% confidence interval 1.0 to 5.4; P=0.05), whereas the combination of sensitisation, high exposure to one or more allergens, and viral detection considerably increased the risk of being admitted with asthma (8.4, 2.1 to 32.8; P=0.002).
Conclusions
Allergens and viruses may act together to exacerbate asthma.
What is already known on this topicStudies on segmental allergen challenge of the lung and experimental rhinovirus infection show synergistic effects between allergens and respiratory virus infectionNo studies have investigated an interaction between sensitisation, exposure to allergens, and virus infections in real life exacerbations of asthmaWhat this study addsAllergens and viruses may act together to exacerbate asthma, indicating that domestic exposure to allergens acts synergistically with viruses in sensitised patients, increasing the risk of hospital admissionStrategies to reduce the impact of asthma exacerbations in adults should include interventions directed at both viruses and reducing exposure to allergens
PMCID: PMC100316  PMID: 11923159
15.  Indoor mold and Children's health 
Environmental Health Perspectives  1999;107(Suppl 3):463.
Reactive airways disease in children is increasing in many countries around the world. The clinical diagnosis of asthma or reactive airways disease includes a variable airflow and an increased sensitivity in the airways. This condition can develop after an augmented reaction to a specific agent (allergen) and may cause a life-threatening situation within a very short period of exposure. It can also develop after a long-term exposure to irritating agents that cause an inflammation in the airways in the absence of an allergen. (paragraph) Several environmental agents have been shown to be associated with the increased incidence of childhood asthma. They include allergens, cat dander, outdoor as well as indoor air pollution, cooking fumes, and infections. There is, however, increasing evidence that mold growth indoors in damp buildings is an important risk factor. About 30 investigations from various countries around the world have demonstrated a close relationship between living in damp homes or homes with mold growth, and the extent of adverse respiratory symptoms in children. Some studies show a relation between dampness/mold and objective measures of lung function. Apart from airways symptoms, some studies demonstrate the presence of general symptoms that include fatigue and headache and symptoms from the central nervous system. At excessive exposures, an increased risk for hemorraghic pneumonia and death among infants has been reported. (paragraph) The described effects may have important consequences for children in the early years of life. A child's immune system is developing from birth to adolescence and requires a natural, physiologic stimulation with antigens as well as inflammatory agents. Any disturbances of this normal maturing process will increase the risk for abnormal reactions to inhaled antigens and inflammagenic agents in the environment. (paragraph) The knowledge about health risks due to mold exposure is not widespread and health authorities in some countries may not be aware of the serious reactions mold exposure can provoke in some children. Individual physicians may have difficulty handling the patients because of the lack of recognition of the relationship between the often complex symptoms and the indoor environment (paragraph) The workshop was organized to develop a basis for risk assessment and formulation of recommendations, particularly for diagnostic purposes and prevention, and to formulate priorities for future research. The participants were all active researchers with current experience in child health, molds, and respiratory disease. They were engaged in free and intensive discussions on a scientific basis throughout the duration of the 3-day workshop (paragraph) This monograph contains peer-reviewed papers based on individual presentations at the workshop as well as the workshop conclusions. They are offered to the public health community, administrators, research agencies, physicians, particularly pediatricians, nurses and health workers as information and encouragement to engage themselves in this health problem of importance for the next generation in our population. (paragraph) Acknowledgments: The workshop received financial support from the U.S. Environmental Protection Agency, the National Center for Environmental Assessment at the U.S. EPA, the Vardal Foundation (Sweden), Astra Corp (Sweden), the Committee on Organic Dusts, International Commission on Occupational Health. The printing of this document was made possible by a grant from the Center for Indoor Air Research (U.S.). Yvonne Peterson, research secretary, provided excellent and invaluable assistance in the organization and publication efforts.
PMCID: PMC1566224  PMID: 10346994
16.  Gene-Environment Interaction in the Onset of Eczema in Infancy: Filaggrin Loss-of-Function Mutations Enhanced by Neonatal Cat Exposure  
PLoS Medicine  2008;5(6):e131.
Background
Loss-of-function variants in the gene encoding filaggrin (FLG) are major determinants of eczema. We hypothesized that weakening of the physical barrier in FLG-deficient individuals may potentiate the effect of environmental exposures. Therefore, we investigated whether there is an interaction between FLG loss-of-function mutations with environmental exposures (pets and dust mites) in relation to the development of eczema.
Methods and Findings
We used data obtained in early life in a high-risk birth cohort in Denmark and replicated the findings in an unselected birth cohort in the United Kingdom. Primary outcome was age of onset of eczema; environmental exposures included pet ownership and mite and pet allergen levels. In Copenhagen (n = 379), FLG mutation increased the risk of eczema during the first year of life (hazard ratio [HR] 2.26, 95% confidence interval [CI] 1.27–4.00, p = 0.005), with a further increase in risk related to cat exposure at birth amongst children with FLG mutation (HR 11.11, 95% CI 3.79–32.60, p < 0.0001); dog exposure was moderately protective (HR 0.49, 95% CI 0.24–1.01, p = 0.05), but not related to FLG genotype. In Manchester (n = 503) an independent and significant association of the development of eczema by age 12 mo with FLG genotype was confirmed (HR 1.95, 95% CI 1.13–3.36, p = 0.02). In addition, the risk increased because of the interaction of cat ownership at birth and FLG genotype (HR 3.82, 95% CI 1.35–10.81, p = 0.01), with no significant effect of the interaction with dog ownership (HR 0.59, 95% CI 0.16–2.20, p = 0.43). Mite-allergen had no effects in either cohort. The observed effects were independent of sensitisation.
Conclusions
We have demonstrated a significant interaction between FLG loss-of-function main mutations (501x and 2282del4) and cat ownership at birth on the development of early-life eczema in two independent birth cohorts. Our data suggest that cat but not dog ownership substantially increases the risk of eczema within the first year of life in children with FLG loss-of-function variants, but not amongst those without. FLG-deficient individuals may need to avoid cats but not dogs in early life.
In two independent cohorts of children, Hans Bisgaard and colleagues show an association between mutations in the filaggrin gene (FLG) and ownership of cats, but not dogs, with development of eczema.
Editors' Summary
Background.
Eczema is a skin condition characterized by dry, red, and itchy patches on the skin. Eczema is associated with asthma and allergy, though allergy rarely plays a role in development or severity of eczema. Eczema usually begins during infancy, typically on the face, scalp, neck, extensor sides of the forearms, and legs. Up to one in five infants develops eczema, but in more than half of them, the condition improves or disappears completely before they are 15 years old. If eczema persists into adulthood, it usually affects the face and the skin inside the knees and elbows. There is no cure for eczema but it can be controlled by avoiding anything that makes its symptoms worse. These triggers include irritants such as wool, strong soaps, perfumes, and dry environments. A good skin-care routine and frequent moisturizing can also help to keep eczema under control, but in many cases, corticosteroid creams and ointments may be necessary to reduce inflammation.
Why Was This Study Done?
Eczema tends to run in families. This suggests that eczema is caused by genetic factors as well as by environmental factors. Recently, researchers discovered that two common “loss-of-function” variants in the gene encoding filaggrin (FLG) predispose people to eczema. People who inherit one or two defective genes make no filaggrin, a protein that normally forms a physical barrier in the skin that protects the body from potentially harmful substances in the environment. Might the weakening of this barrier in filaggrin-deficient individuals affect their responses to environmental substances to which the skin is exposed? In this study, the researchers test this potential explanation for how genetic and environmental factors (in particular, exposure to pets) might interact to determine an individual's chances of developing eczema.
What Did the Researchers Do and Find?
To test their hypothesis, the researchers studied two independent groups of infants during their first year of life—a high-risk group consisting of infants born in Copenhagen, Denmark to mothers with asthma and a group of infants born to women from the general population in Manchester, United Kingdom. The researchers determined which FLG variants each child had inherited and classified those with either one or two defective copies of FLG as having an FLG mutation. They determined pet exposure in early life by asking whether a dog or a cat was living in the parental home when the child was born (“pet ownership”) and then analyzed how these genetic and environmental factors affected the age of onset of eczema. In both groups, children with FLG mutations were twice as likely to develop eczema during the first year of life as children without FLG mutations. For children without FLG mutations, cat ownership at birth had no effect on eczema risk but for children with FLG mutations, cat ownership at birth (but not dog ownership) further increased the risk of developing eczema.
What Do These Findings Mean?
These findings show that FLG mutations and cat ownership at birth interact to determine the chances of a child developing eczema during the first year of life. They provide support, therefore, for the researchers' suggestion that the weakening of the skin's protective barrier that is caused by filaggrin deficiency increases the child's susceptibility to factors associated with cat exposure. Only a small number of children in this study carried FLG mutations and were exposed to cats from birth, so these findings need confirming in independent studies. In addition, it is still not clear how exposure to cats drives the development of eczema. Allergy was not the mechanism as the FLG-deficient children exposed to cat and who developed eczema did not develop cat-specific immunoglobin E antibodies. Nevertheless, these findings suggest that, to reduce their risk of developing eczema, filaggrin-deficient individuals should avoid cats (but not dogs) during the first few months of life.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050131.
The MedlinePlus Encyclopedia has a page on eczema (in English and Spanish); links to further information are provided by MedlinePlus
EczemaNet is a comprehensive online information resource about eczema provided by the American Academy of Dermatologists
The US National Institute of Arthritis and Musculoskeletal and Skin Diseases provides information on eczema
The UK National Health Service Direct health encyclopedia provides information for patients on eczema (in several languages)
The Copenhagen Studies on Asthma in Childhood (COPSAC) and Manchester Asthma and Allergy Study (MAAS) Web sites provide more information about the children involved in this research
doi:10.1371/journal.pmed.0050131
PMCID: PMC2504043  PMID: 18578563
17.  Environmental Issues in Managing Asthma 
Respiratory care  2008;53(5):602-617.
Management of asthma requires attention to environmental exposures both indoors and outdoors. Americans spend most of their time indoors, where they have a greater ability to modify their environment. The indoor environment contains both pollutants (eg, particulate matter, nitrogen dioxide, secondhand smoke, and ozone) and allergens from furred pets, dust mites, cockroaches, rodents, and molds. Indoor particulate matter consists of particles generated from indoor sources such as cooking and cleaning activities, and particles that penetrate from the outdoors. Nitrogen dioxide sources include gas stoves, furnaces, and fireplaces. Indoor particulate matter and nitrogen dioxide are linked to asthma morbidity. The indoor ozone concentration is mainly influenced by the outdoor ozone concentration. The health effects of indoor ozone exposure have not been well studied. In contrast, there is substantial evidence of detrimental health effects from secondhand smoke. Guideline recommendations are not specific for optimizing indoor air quality. The 2007 National Asthma Education and Prevention Program asthma guidelines recommend eliminating indoor smoking and improving the ventilation. Though the guidelines state that there is insufficient evidence to recommend air cleaners, air cleaners and reducing activities that generate indoor pollutants may be sound practical approaches for improving the health of individuals with asthma. The guidelines are more specific about allergen avoidance; they recommend identifying allergens to which the individual is immunoglobin E sensitized and employing a multifaceted, comprehensive strategy to reduce exposure. Outdoor air pollutants that impact asthma include particulate matter, ozone, nitrogen dioxide, and sulfur dioxide, and guidelines recommend that individuals with asthma avoid exertion outdoors when these pollutants are elevated. Outdoor allergens include tree, grass, and weed pollens, which vary in concentration by season. Recommendations to reduce exposure include staying indoors, keeping windows and doors closed, using air conditioning and perhaps high-efficiency particulate arrestor (HEPA) air filters, and thorough daily washing to remove allergens from one’s person.
PMCID: PMC2396450  PMID: 18426614
asthma; pollutants; particulate matter; nitrogen dioxide; sulfur dioxide; secondhand smoke; ozone; allergens
18.  Few Associations Found between Mold and Other Allergen Concentrations in the Home versus Skin Sensitivity from Children with Asthma after Hurricane Katrina in the Head-Off Environmental Asthma in Louisiana Study 
Mold and other allergen exposures exacerbate asthma symptoms in sensitized individuals. We evaluated allergen concentrations, skin test sensitivities, and asthma morbidity for 182 children, aged 4–12 years, with moderate to severe asthma, enrolled 18 months after Katrina, from the city of New Orleans and the surrounding parishes that were impacted by the storm, into the Head-off Environmental Asthma in Louisiana (HEAL) observational study. Dust (indoor) and air (indoor and outdoor) samples were collected at baseline of 6 and 12 months. Dust samples were evaluated for dust mite, cockroach, mouse, and Alternaria by immunoassay. Air samples were evaluated for airborne mold spore concentrations. Overall, 89% of the children tested positive to ≥1 indoor allergen, with allergen-specific sensitivities ranging from 18% to 67%. Allergen concentration was associated with skin sensitivity for 1 of 10 environmental triggers analyzed (cat). Asthma symptom days did not differ with skin test sensitivity, and surprisingly, increased symptoms were observed in children whose baseline indoor airborne mold concentrations were below median levels. This association was not observed in follow-up assessments. The lack of relationship among allergen levels (including mold), sensitivities, and asthma symptoms points to the complexity of attempting to assess these associations during rapidly changing social and environmental conditions.
doi:10.1155/2012/427358
PMCID: PMC3523147  PMID: 23304171
19.  Prevalence of Indoor Allergen Exposures among New Orleans Children with Asthma 
Studies of inner-city asthmatic children have shown significant regional variation in dust allergen exposures. The home environment of asthmatic children in the Gulf South region of the USA has not been characterized. This study describes indoor dust allergen levels in the homes of 86 asthmatic children in New Orleans and explores regional variability in dust allergen exposure. Data were used from baseline home visits of children in the New Orleans Healthy Homes Initiative. Interview, visual observation, and environmental dust sampling data of 86 children between 4 and 17 years of age were analyzed. Seventy-seven percent of households had moderate (>2.0–9.9 μg/g) or high (≥10.0 μg/g) levels of either Der p 1 or Der f 1 dust mite allergen and 56.6% had moderate (>2.0–8.0 U/g) or high (>8.0 U/g) levels of cockroach allergen (Bla g 1). The prevalence of high (>10 μg/g) levels of dog (Can f 1) allergen was 26.5%, and few households (6.0%) had high cat allergen (Fel d 1) levels (>8.0 μg/g). Households with average humidity levels >50% were three times more likely to have elevated dust mite levels (odds ratio=3.2; 95% confidence interval=1.1, 9.3; p=0.03). Home ownership and education level were inversely associated with cockroach and dust mite allergen levels, respectively. Our findings reinforce the evidence of regional variability in dust allergen exposure levels. Asthmatic children living in the Gulf South are exposed to multiple indoor allergen exposures and live in a highly allergenic environment.
doi:10.1007/s11524-007-9216-0
PMCID: PMC2232043  PMID: 17917814
Child health; Asthma; Allergens; Environmental health; Dog allergen; House dust
20.  Do Questions Reflecting Indoor Air Pollutant Exposure from a Questionnaire Predict Direct Measure of Exposure in Owner-Occupied Houses? 
Home characteristic questions are used in epidemiological studies and clinical settings to assess potentially harmful exposures in the home. The objective of this study was to determine whether questionnaire-reported home characteristics can predict directly measured pollutants. Sixty home inspections were conducted on a subsample of the 2006 population-based Toronto Child Health Evaluation Questionnaire. Indoor/outdoor air and settled dust samples were analyzed. Mean Fel d 1 was higher (p < 0.0001) in homes with a cat (450.58 μg/g) versus without (22.28 μg/g). Mean indoor NO2 was higher (p = 0.003) in homes with gas stoves (14.98 ppb) versus without (8.31 ppb). Self-reported musty odours predicted higher glucan levels (10554.37 μg/g versus 6308.58 μg/g, p = 0.0077). Der f 1 was predicted by the home’s age, but not by reports of carpets, and was higher in homes with mean relative humidity > 50% (61.30 μg/g, versus 6.24 μg/g, p = 0.002). Self-reported presence of a cat, a gas stove, musty odours, mice, and the home’s age and indoor relative humidity over 50% predicted measured indoor levels of cat allergens, NO2, fungal glucan, mouse allergens and dust mite allergens, respectively. These results are helpful for understanding the significance of indoor exposures ascertained by self-reporting in large epidemiological studies and also in the clinical setting.
doi:10.3390/ijerph7083270
PMCID: PMC2954581  PMID: 20948960
allergens; environmental exposure; house dust; indoor air pollution; questionnaire
21.  Allergen exposure modifies the relation of sensitization to FENO levels in children at risk for allergy and asthma 
Background
Studies on airway inflammation, measured as fraction exhaled nitric oxide (FENO), have focused on its relation to control of asthma, but the contribution of allergen exposure to elevation of FENO is unknown.
Objective
We evaluated (1) whether FENO was elevated in children with allergic sensitization or asthma; (2) whether specific allergen exposure increased FENO levels in sensitized, but not in unsensitized children; and (3) whether sedentary behavior increased FENO, independent of allergen exposures.
Methods
At age 12, in a birth cohort of children with parental history of allergy or asthma, we measured bed dust allergen (dust mite, cat, cockroach) by ELISA; specific allergic sensitization primarily by specific IgE ; and respiratory disease (current asthma, rhinitis, and wheeze) and hours of TV viewing/video game playing by questionnaire. Children performed spirometry maneuvers before and after bronchodilator responses, and had FENO measured using electrochemical detection methods (NIOX MINO).
Results
FENO was elevated in children with current asthma (32.2 ppb), wheeze (27.0 ppb), or rhinitis (23.2ppb) as compared to individuals without these respective symptoms/diagnoses (16.4 ppb to 16.6 ppb, p< 0.005 for all comparisons). Allergic sensitization to indoor allergens (cat, dog, dust mite) predicted higher levels of FENO, and explained one third of the variability of FENO. FENO levels were highest in children both sensitized and exposed to dust mite. Greater than 10 hours of weekday TV viewing was associated with a 0.64 log increase in FENO, after controlling indoor allergen exposure, BMI and allergic sensitization.
Conclusion
Allergen exposures and sedentary behavior (TV viewing/ video game playing), may increase airway inflammation, measured as FENO.
doi:10.1016/j.jaci.2011.01.066
PMCID: PMC3137133  PMID: 21463890
Asthma; dust mite; cat; allergens; exhaled NO; allergic sensitization; home environment
22.  A major house dust mite allergen disrupts the immunoglobulin E network by selectively cleaving CD23: innate protection by antiproteases 
The Journal of Experimental Medicine  1995;182(5):1537-1544.
Asthma is a chronic life-threatening disease of worldwide importance. Although allergic asthma and related atopic conditions correlate strongly with immune sensitization to house dust mites, it is unclear why antigens from mites provoke such powerful allergic immune responses. We have characterized the protease activity of Der p I, the group I protease allergen of the house dust mite Dermatophagoides pteronyssinus, and here report that it cleaves the low-affinity immunoglobulin (Ig) E Fc receptor (CD23) from the surface of human B lymphocytes. Der p I selectively cleaves CD23 and has no effect on the expression of any other B cell surface molecules tested. We speculate that this loss of cell surface CD23 from IgE-secreting B cells may promote and enhance IgE immune responses by ablating an important feedback inhibitory mechanism that normally limits IgE synthesis. Furthermore, since soluble CD23 is reported to promote IgE production, fragments of CD23 released by Der p I may directly enhance the synthesis of IgE. alpha 1-Antiprotease, a pulmonary antiprotease, is also shown to inhibit the cleavage of CD23 by Der p I. This may be significant in the etiopathogenesis of asthma, because other indoor pollutants associated with asthma are known to potently inhibit this antiprotease. These data suggest that the proteolytic activity of Der p I, the group I allergen of the house dust mite D. pteronyssinus, is mechanistically linked to the potent allergenicity of house dust mites. Furthermore, inhibition of Der p I by alpha 1-antiprotease suggests a mechanism by which confounding factors, such as tobacco smoke, may act as a risk factor for allergic asthma.
PMCID: PMC2192194  PMID: 7595223
23.  The indoor air and asthma: the role of cat allergens 
Purpose of review
The objective is to discuss recent progress in our understanding of the role of the indoor environment in asthma, focusing on the special role of cat allergens.
Recent findings
Sensitization to Fel d 1 is the dominant event in inhalant responses to cat; however, there are also IgE responses to the lipocalin (Fel d 4), to cat albumin (Fel d 2), and to the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal) on cat IgA (Fel d 5w) and other molecules. The dose response and routes of sensitization for these allergens are now thought to be diverse. It is important to remember that exposure outside a house with a cat is sufficient to cause sensitization. Furthermore, the only solid evidence about a role in asthma relates to Fel d 1. Recently, it has been shown that tolerance associated with early exposure to cats can persist to age 18 and that IgE to alpha-gal (on cat IgA) is not related to asthma. In addition, a recent study of anti-IgE reinforces the evidence that IgE antibodies to indoor allergens make a major contribution to asthma severity.
Summary
Exposure to Fel d 1 in a home with a cat is far higher than the levels necessary to induce an allergic (IgE antibody) response. In keeping with that, children may develop tolerance, which can be long-lived. In addition, there is increasing evidence that IgE antibodies to an inhalant allergen, such as Fel d 1, dust mite, or cockroach, are causally related to lung inflammation and asthma.
doi:10.1097/MCP.0b013e32834db10d
PMCID: PMC3707607  PMID: 22081090
asthma; cats; inhalant allergens; Fel d 1; long-term tolerance
24.  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-γ) 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.
doi:10.1186/1476-7961-8-11
PMCID: PMC2922078  PMID: 20684781
25.  The challenge of preventing environmentally related disease in young children: community-based research in New York City. 
Environmental Health Perspectives  2002;110(2):197-204.
Rates of developmental and respiratory diseases are disproportionately high in underserved, minority populations such as those in New York City's Washington Heights, Harlem, and the South Bronx. Blacks and Latinos in these neighborhoods represent high risk groups for asthma, adverse birth outcomes, impaired development, and some types of cancer. The Columbia Center for Children's Environmental Health in Washington Heights uses molecular epidemiologic methods to study the health effects of urban indoor and outdoor air pollutants on children, prenatally and postnatally, in a cohort of over 500 African-American and Dominican (originally from the Dominican Republic) mothers and newborns. Extensive data are collected to determine exposures to particulate matter < 2.5 microm in aerodynamic diameter (PM(2.5)), polycyclic aromatic hydrocarbons (PAHs), diesel exhaust particulate (DEP), nitrogen oxide, nonpersistent pesticides, home allergens (dust mite, mouse, cockroach), environmental tobacco smoke (ETS), and lead and other metals. Biomarkers, air sampling, and clinical assessments are used to study the effects of these exposures on children's increased risk for allergic sensitization, asthma and other respiratory disorders, impairment of neurocognitive and behavioral development, and potential cancer risk. The center conducts its research and community education in collaboration with 10 community-based health and environmental advocacy organizations. This unique academic-community partnership helps to guide the center's research so that it is most relevant to the context of the low-income, minority neighborhoods in which the cohort resides, and information is delivered back to these communities in meaningful ways. In turn, communities become better equipped to relay environmental health concerns to policy makers. In this paper we describe the center's research and its academic-community partnership and present some preliminary findings.
PMCID: PMC1240736  PMID: 11836150

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