Original article
Mechanisms of allergic and immune disease
A comparison of subject room dust with home vacuum dust for evaluation of dust-borne aeroallergens

https://doi.org/10.1016/j.anai.2013.02.010Get rights and content

Abstract

Background

Assessment of indoor allergen is valuable in exposure research and evaluation of allergic individuals. Collection methods range from grab vacuum samples to filtration devices located in the breathing range of an individual. For practical purposes, many research studies use analysis of collected house dust to evaluate allergen reservoirs.

Objective

To test the hypothesis that house dust collected from the family vacuum is equivalent to house dust collected by a technician following standard protocol.

Methods

Homes from a healthy homes demonstration project (n = 41) were sampled using a specific Department of Housing and Urban Development–suggested protocol in the bedroom of the child with asthma and a simple grab procedure from the family vacuum. Samples were evaluated for the presence of 5 allergens, Bla g2, Can f1, Der f1, and Der p1 combined as total mite, Fel d1, and Mus m1. Samples were also evaluated for total antigenic protein from 4 fungal taxa, including Alternaria, Aspergillus, Cladosporium, and Penicillium.

Results

All of the allergens and antigens tested showed good correlation between the 2 collection methods. Fungal antigens ranged up to 92,651 nanograms per gram of dust for Aspergillus, and allergens ranged up to 17,928 nanograms per gram of dust for Can f1. The best correlation was for Cladosporium (r = 0.91), and the weakest was for dust mite (r = 0.34).

Conclusion

Allergens and antigens tested from samples collected by protocol and by grab sampling from the home vacuum were highly positively correlated. Grab samples taken from the family vacuum may be a good surrogate for evaluating home allergen exposure.

Introduction

Domestic allergen exposures remain at the top of the list of controllable factors related to asthma in children.1 Measurement of allergen proteins in house dust has been very useful in identifying environmental agents that are at the root of human allergic disease and function to trigger asthma attacks. From the beginning of allergen measurements in house dust,2 there has been discussion as to the best collection methods and which collection protocols are most representative of human exposure. The most accurate method, however, is still not known.[3], [4] In light of the need for frequent monitoring to adequately assess exposure and gauge potential reductions that might lead to asthma symptom reduction, the practicality of patient-collected dust samples for allergen testing has been proposed.

The measurement of allergen reservoir levels is an important aspect of effective allergen trigger control. The cost effectiveness of allergen reduction and thereby the utility of allergen measurements has been demonstrated previously.5 In 1 study of improved asthma as a result of environmental control, within the intervention group there was a significant relationship between the reduction of dust aeroallergens and asthma symptom improvement.6 Allergen measurements were repeated every 6 months, and results from aeroallergen testing were used as part of motivational education and modeled behavioral changes to reduce aeroallergen exposures. Even though it has not been possible to consistently demonstrate the effectiveness of isolated allergen trigger control strategies,7 numerous studies have shown targeted interventions involving multiple control strategies to be effective in reducing asthma symptoms and health care use.[6], [8], [9], [10]

In this work, we aim to determine the relationship between allergen content in dust collected by a field worker according to a specific protocol and samples a patient could take from their home vacuum. We hypothesize that a dust sample collected from the home vacuum unit of a family, assuming the unit is used regularly and only in the home, would be a good proxy for that collected by a trained investigator.

Section snippets

Home selection and characteristics

Homes in this study were a subset of homes that participated in the Kansas City Safe and Healthy Homes Program. Homes participating in this program had at least 1 child with asthma resident for a minimum of 4 days per week. Asthma severity ranged from mild to severe. Homes in the program were assessed by environmental health professionals before and after a series of targeted interventions designed to improve the indoor air quality of the home. Homeowners received a new vacuum cleaner at the

Results

The Healthy Homes Demonstration project screened a total of 1,473 families for enrollment, of which 382 families were enrolled and 302 families completed the study. Reasons for not enrolling in the study included failure to complete enrollment information, income greater than 80% of median family income (Department of Housing and Urban Development stipulation for participation), and plans to relocate during the time of the study. Reasons for not completing the study included repeated failure to

Discussion

Early reviews on home allergen measurement used polyclonal antibodies and expressed results per square meter.12 Subsequent discussion as to practical methods for dust sampling has been extensive.13 A continuously operating filter device worn on the collar or a particle retaining device worn in the nose constitutes the gold standard of exposure monitoring. In light of the reduced practicality of these devices, measurement of allergens from vacuum-collected house dust has become the most commonly

Acknowledgment

The authors wish to acknowledge the Center for Environmental Health at Children's Mercy Hospital for their assistance with the completion of this study, including Kevin Kennedy, MS, Ryan Allenbrand, MFS, Minati Dhar, PhD, Erica Forrest, MS, RRT, Luke Gard, Jennifer Lowry, MD, Mubeen Mohammed, MS, Anita Didonna, and Tanisha Webb, RRT.

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    Disclosures: Authors have nothing to disclose.

    Funding Sources: Funded by Children's Mercy Hospital and by a Healthy Homes Demonstration Project Award from Housing and Urban Development.

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