Article

Dustborne Alternaria alternata antigens in US homes: Results from the National Survey of Lead and Allergens in Housing

Harvard University, Cambridge, Massachusetts, United States
Journal of Allergy and Clinical Immunology (Impact Factor: 11.48). 10/2005; 116(3):623-9. DOI: 10.1016/j.jaci.2005.05.030
Source: PubMed

ABSTRACT

Alternaria alternata is one of the most common fungi associated with allergic disease. However, Alternaria exposure in indoor environments is not well characterized.
The primary goals of this study were to examine the prevalence of Alternaria exposure and identify independent predictors of Alternaria antigen concentrations in US homes.
Data for this cross-sectional study were obtained from the National Survey of Lead and Allergens in Housing. A nationally representative sample of 831 housing units in 75 different locations throughout the United States completed the survey. Information on housing and household characteristics was obtained by questionnaire and environmental assessments. Concentrations of A alternata antigens in dust collected from various indoor sites were assessed with a polyclonal anti-Alternaria antibody assay.
Alternaria antigens were detected in most (95% to 99%) of the dust samples. The geometric mean concentration, reflecting the average Alternaria concentration in homes, was 4.88 microg/g (SEM, 0.13 microg/g). In the multivariable linear regression analysis, the age of the housing unit, geographic region, urbanization, poverty, family race, observed mold and moisture problems, use of de-humidifier, and presence of cats and dogs were independent predictors of Alternaria antigen concentrations. Less frequent cleaning and smoking indoors also contributed to higher Alternaria antigen levels in homes.
Exposure to A alternata antigens in US homes is common. Antigen levels in homes are influenced not only by regional factors but also by residential characteristics. Preventing mold and moisture problems, avoiding smoking indoors, and regular household cleaning may help reduce exposure to Alternaria antigens indoors.

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Available from: Richard D Cohn, Apr 08, 2015
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    • "Few studies have investigated indoor Alternaria isolates specifically , although multiple studies mention the detection of Alternaria in the indoor environment (de Ana et al., 2006; Li and Kendrick, 1995; Solomon, 1975). One large study of dust-borne A. alternata allergens in USA homes assessed the concentration of Alternaria allergens in dust with a polyclonal anti-alternaria antibody assay (Salo et al., 2005). That study revealed that exposure to A. alternata allergens is common, and that residential characteristics such as smoking, mold and moisture problems, and cleaning frequencies influence the indoor antigen levels in house dust. "

    Full-text · Dataset · Aug 2015
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    • "Few studies have investigated indoor Alternaria isolates specifically , although multiple studies mention the detection of Alternaria in the indoor environment (de Ana et al., 2006; Li and Kendrick, 1995; Solomon, 1975). One large study of dust-borne A. alternata allergens in USA homes assessed the concentration of Alternaria allergens in dust with a polyclonal anti-alternaria antibody assay (Salo et al., 2005). That study revealed that exposure to A. alternata allergens is common, and that residential characteristics such as smoking, mold and moisture problems, and cleaning frequencies influence the indoor antigen levels in house dust. "
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    ABSTRACT: Alternaria spp. from sect. Alternaria are frequently associated with hypersensitivity pneumonitis, asthma and allergic fungal rhinitis and sinusitis. Since Alternaria is omnipresent in the outdoor environment, it is thought that the indoor spore concentration is mainly influenced by the outdoor spore concentration. However, few studies have investigated indoor Alternaria isolates, or attempted a phylogeographic or population genetic approach to investigate their movement. Therefore, the aim of the current study was to investigate the molecular diversity of indoor Alternaria isolates in the USA, and to test for recombination, using these approaches. Alternaria isolates collected throughout the USA were identified using ITS, gapdh and endoPG gene sequencing. This was followed by genotyping and population genetic inference of isolates belonging to Alternaria sect. Alternaria together with 37 reference isolates, using five microsatellite markers. Phylogenetic analyses revealed that species of Alternaria sect. Alternaria represented 98% (153 isolates) of the indoor isolates collected throughout the USA, of which 137 isolates could be assigned to A. alternata, 15 to the A. arborescens species complex and a single isolate to A. burnsii. The remaining 2% (3 isolates) represented sect. Infectoriae (single isolate) and sect. Pseudoulocladium (2 isolates). Population assignment analyses of the 137 A. alternata isolates suggested that subpopulations did not exist within the sample. The A. alternata isolates were thus divided into four artificial subpopulations to represent four quadrants of the USA. Fourty-four isolates representing the south-western quadrant displayed the highest level of uniqueness based on private alleles, while the highest level of gene flow was detected between the south-eastern (32 isolates) and south-western quadrants. Genotypic diversity was high for all quadrants, and a test for linkage disequilibrium suggested that A. alternata has a cryptic sexual cycle. These statistics could be correlated with environmental factors, suggesting that indoor A. alternata isolates, although extremely diverse, have a continental distribution and high levels of gene flow over the continent. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
    Full-text · Article · May 2015 · Fungal Genetics and Biology
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    • "Regarding molds, studies have repeatedly demonstrated that sensitization to fungi, such as Alternaria alternata is strongly associated with allergic rhinitis and asthma in children in the United States[24,25] and Saudi Arabia.2 Among asthmatic individuals in Kuwait, Candida spp. "
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    ABSTRACT: BACKGROUND:: Airborne allergens vary from one climatic region to another. Therefore, it is important to analyze the environment of the region to select the most prevalent allergens for the diagnosis and treatment of allergic patients. OBJECTIVE:: To evaluate the prevalence of positive skin tests to pollen and fungal allergens collected from local indigenous plants or isolated molds, as well as other outdoor and indoor allergens in allergic patients in 6 different geographical areas in the Kingdom of Saudi Arabia (KSA), the United Arab Emirates, and Sudan. MATERIAL AND METHODS:: Four hundred ninety-two consecutive patients evaluated at different Allergy Clinics (276 women and 256 men; mean age, 30 years) participated in this study. The selection of indigenous allergens was based on research findings in different areas from Riyadh and adjoining areas. Indigenous raw material for pollen grains was collected from the desert near the capital city of Riyadh, KSA. The following plants were included: Chenopodium murale, Salsola imbricata, Rumex vesicarius, Ricinus communis, Artiplex nummularia, Amaranthus viridis, Artemisia monosperma, Plantago boissieri, and Prosopis juliflora. Indigenous molds were isolated from air sampling in Riyadh and grown to obtain the raw material. These included the following: Ulocladium spp., Penicillium spp., Aspergillus fumigatus, Cladosporium spp., and Alternaria spp. The raw material was processed under Good Manufacturing Practices for skin testing. Other commercially available outdoor (grass and tree pollens) and indoor (mites, cockroach, and cat dander) allergens were also tested. RESULTS:: The highest sensitization to indigenous pollens was detected to C. murale (32%) in Khartoum (Sudan) and S. imbricata (30%) and P. juliflora (24%) in the Riyadh region. The highest sensitization to molds was detected in Khartoum, especially to Cladosporium spp. (42%), Aspergillus (40%), and Alternaria spp. (38%). Sensitization to mites was also very prevalent in Khartoum (72%), as well as in Abu Dhabi (United Arab Emirates) (46%) and Jeddah (KSA) (30%). CONCLUSIONS:: The allergenicity of several indigenous pollens and molds derived from autochthonous sources was demonstrated. Prevalence studies in different regions of KSA and neighbor countries indicate different sensitization rates to these and other outdoor and indoor allergens.
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