Allersearch® Laboratories

PRODUCT: Allersearch AllerMold™
RESEARCH: Indoor exposure to molds and allergic sensitization

Evidence that indoor dampness and mold growth are associated with respiratory health has been accumulating, but few studies have been able to examine health risks in relation to measured levels of indoor mold exposure… We examined whether allergic sensitization in children is associated with higher fungal spore count in settled house dust sampled from living room floors. Adjusting for age, sex, parental education, region of residency, and parental history of atopy, we found that mold spore counts for Cladosporium and Aspergillus were associated with an increased risk of allergic sensitization. Sensitized children exposed to high levels of mold spores (> 90th percentile) were more likely to suffer from symptoms of rhinoconjunctivitis. We conclude that elevated indoor concentrations of molds in wintertime might play a role in increasing the risk of developing atopic symptoms and allergic sensitization not only to molds but also to other common, inhaled allergens. These effects were strongest in the group of children who had lived in the same home since birth.

Environ Health Perspect 110:647-653 (2002)

PRODUCT: Allersearch ADS™ and X-Mite
RESEARCH: Chemical treatment of carpets to reduce allergen: A detailed study of the effects of tannic acid on indoor allergens

Tannic acid (TA), a protein-denaturing agent, has been reported to reduce allergen levels in house dust and is marketed for that purpose as 1% and 3% solutions. We investigated the effects of TA on dust allergens by using monoclonal antibody-based ELISAs for mite (Der p I, Der f I, and group II) and cat (Fel d I) allergens. Initial studies confirmed that TA reduced allergen levels in carpet dust... In the laboratory, concentrations of TA as low as 0.1% inhibited the assays, but this effect may be prevented by addition of 5% bovine serum albumin (BSA). After treatment of dust samples in the laboratory with 3% TA, the apparent reductions in Der p I and Der f I levels were 89% and 96%, respectively… Our testing of the ability of TA to denature Fel d I demonstrated an 80% reduction in allergen… The results confirmed the profound denaturing effects of TA.
(J ALLERGY CLIN IMMUNOL 1994;94:19-26.)

PRODUCT: Allersearch ADS™, X-Mite, and ADMS™
RESEARCH: Cat antigen in homes with and without cats may induce allergic symptoms

Although Fel d 1, the major cat allergen, has been found in settled dust samples from homes both with and without cats, the clinical relevance of this allergen has never been studied. In this study we measured airborne concentrations of Fel d 1 in homes both with and without cats and then attempted to relate these levels to those obtained in our experimental cat challenge model to assess their clinical significance. In baseline samples we found measurable levels of airborne Fel d 1 in all 37 homes with cats (range, 1.8 to 578 ng/m³; median, 45.9 ng/m³) and in 10 of the 40 homes without cats (for detectable samples: range, 2.8 to 88.5 ng/m³; median, 17 ng/m³). Fel d 1 was present in the settled dust of 38 of 40 homes without cats (range, 39 to 3750 ng/gm; median, 258 ng/gm), although these levels were only weakly predictive of airborne levels. Repeat samples obtained weekly from 12 homes without cats yielded measurable airborne Fel d 1 in at least one of the four samples from all homes. When compared with challenges performed in our cat room facility at low levels of airborne Fel d 1 (<500 ng/m³), these home levels are within the range capable of causing upper and lower respiratory symptoms in subjects allergic to cats. We therefore conclude that the low level cat exposure that occurs in many homes without cats is capable of inducing symptoms in some patients who are sensitive to cats. The assessment of cat exposure should not be based solely on the presence or absence of a cat in the home.
(J ALLERGY CLIN IMMUNOL 1996;97:907-14.)

PRODUCT: Allersearch Allergen Wash™
RESEARCH: Domestic control of house dust mite allergen in children’s beds

Background:

House dust mite allergen levels in humid coastal regions of Australia are high, particularly in beds. Because high allergen levels in beds are associated with more severe asthma, reduction of levels may be important for asthma control.

Objective:

We tested the effectiveness of an acaricidal treatment of bedding in combination with occlusive mattress and pillow encasings in reducing allergen levels in children’s beds in a community setting.

Methods:

A total of 14 beds of children were selected for the active intervention. In each home the bed of a sibling of nearest age was selected as the control. Dust was vacuumed from beds by using a standard protocol, and Der p 1 levels were measured by using ELISA. Adjacent settling dust was collected by using opened Petri dishes. The intervention consisted of encasing mattresses and pillows in occlusive covers and washing all bedding with Acaril, an acaricidal additive. The acaricidal wash was repeated twice in 7 households at 2-month intervals. Control beds were not treated.

Results:

The mean Der p 1 concentration at baseline was 27.9 µg/g in the active beds and 18.1 µg/g in the control beds. At 4 days after intervention, Der p 1 decreased to 3.2 µg/g and 15.7 µg/g in active and control beds, respectively. The average difference (active minus control) over the first 8-week cycle was 78.5% (P < .0001), and the difference over 3 washing cycles was 125.1% (P < .05). The mean rate of settling Der p 1 adjacent to the actively treated beds decreased from 24.4 ng·m^–2·d^–1 at baseline to 10.0 ng·m^–2·d^–1 after intervention (P < .01).

Conclusion:

A substantial reduction in Der p 1 levels in beds and in airborne dust in a humid region with naturally high house dust mite allergen levels can be achieved and sustained in a community setting with use of occlusive covers and a rigorous washing routine.

(J Allergy Clin Immunol 2000;105: 1130-3.)

PRODUCT: Allersearch Allergen Wash™
RESEARCH: Exposure to mite and cat allergens on a range of clothing items at home and the transfer of cat allergen in the workplace

Background:

Clothing has been proposed as an additional source of exposure to mite and cat allergens. Dispersal of allergen into public places has also been attributed to clothing.

Objectives:

We sought to study the contribution of various types of clothing on mite and cat exposure in a domestic environment. Also, we studied the ability of clothing to transfer allergen in a workplace.

Methods:

Personal exposure to mite and cat allergen from a range of clothing was measured by using intranasal air samplers in 11 homes. Five categories of clothing were tested. Wearing no upper clothing was the sixth category tested to distinguish the contribution of clothing over ambient background exposure. An adhesive tape was used to sample allergen from the surface of clothing, and reservoir dust samples were also collected. The above techniques were also used in the workplace to examine the amount of cat allergen transferred from cat owners to non-cat owners.

Results:

The amount of mite and cat allergen inhaled differed among the clothing types worn and whether they had been washed recently. Wearing a woolen sweater increased personal allergen exposure to cat and mite allergen by a mean of 11 and 10 times, respectively. Clothing items that were less frequently washed carried more allergen whether assessed by vacuuming or sampled with adhesive tape. This corresponded to the amount of allergen inhaled. We also found that cat levels on non-cat owners’ clothing increased significantly at the end of a working day, which lead to the increase in their personal allergen exposure to cat.

Conclusions:

These studies strongly support the emerging model that personal clothing is an important source of both mite and cat allergen exposure. This article also demonstrates the importance of clothing as a means of distributing cat allergen into cat-free environments.
(J Allergy Clin Immunol 2000;106:874-9.)

PRODUCT: Allersearch Pet +™
RESEARCH: Evaluation of different techniques for washing cats: Quantitation of allergen removed from the cat and the effect on airborne Fel d 1

Background and Objective:

The purpose of this study was to examine the quantity and distribution of the major cat allergen, Fel d 1, on cats and to evaluate the efficacy of washing, both in removing allergen from the cat and reducing airborne allergen levels.

Methods:

Airborne samples were collected on four glass fiber filters in a 30 m³ room, before and 3 hours after serial washing of eight cats (45-minute sampling at 18 L/min for each filter). Aliquots of hair and bath water were also collected and assayed for Fel d 1 content.

Results:

Extracting cat hair with tap water or pet shampoo for 3 minutes removed mean levels of 191 and 245 µg of Fel d 1 per gram of hair, respectively; the quantity of allergen on samples of cat hair ranged from 1 µg/gm to more than 1770 µg/gm. The highest concentration of allergen was found on hair from the neck. Estimates of the total Fel d 1 on the cat, based on shaving the whole cat, ranged from 3 to 142 mg (mean = 67 mg). Washing cats reduced airborne allergen 3 hours later. Washing three cats at weekly intervals for 5 weeks in a veterinarian's office produced a mean decrease of 44% in airborne Fel d 1 (n = 15, p < 0.02). Washing three cats by immersion for 3 minutes at weekly intervals for a 1-month period produced a mean decrease in airborne allergen of 79% (n = 12, p < 0.001)…

Conclusion:

Cats carry large quantities of Fel d 1, only a small proportion of which (~0.002%/hr) becomes airborne. Washing cats by immersion will remove significant allergen from the cat and can reduce the quantity of Fel d 1 becoming airborne.
(J Allergy Clin Immunol 1997;100:307-12.)

PRODUCT: Allersearch AllerDust™
RESEARCH: Airborne dust and allergen generation during dusting with and without spray polish

Background:

Dusting is a commonly used method for dust removal from surfaces in the home. However, the process of dusting may contribute to airborne dust levels by disturbing dust particles from a surface and failing to remove it from the indoor environment.

Objective:

We sought to measure the quantity of allergen-laden dust disturbed into the air during dusting and discover whether applying spray polish to either the dusty surface or the cleaning cloth reduced this amount.

Methods:

A common furniture polish was tested for its ability to prevent dust particles and major house dust mite (Der p 1) or major cat (Fel d 1) allergen from becoming airborne during dusting. Tests were completed with a repeatable mechanized dusting procedure with polish sprayed onto either a cleaning cloth or directly onto a surface, and this was compared with a control procedure with a standard duster. Airborne dust was measured with an air-particle counter and by means of anti-Der p 1 or anti-Fel d 1 ELISA.

Results:

Considerable quantities of dust became airborne during dusting. When polish was sprayed onto the cleaning cloth, the concentration of airborne dust particles was reduced by a mean of 83.4%, house dust mite allergen by 50.3%, and cat allergen by 57.4% when compared with dry-cloth controls…. All reductions were significant when compared with dry-cloth controls (P < .01, Mann-Whitney U test).

Conclusions:

This study showed that application of a polish spray to … the cloth during dusting greatly reduced dust and allergen evolution into the air, which should reduce exposure to airborne allergens in the home.

(J Allergy Clin Immunol 2002;109:63-7.)

RESEARCH: Methods and effectiveness of environmental control
In recent years the role of allergen exposure and atopy, and the interaction between them in the clinical expression of allergic disease, has been examined in a quantitative manner in epidemiologic studies. Such analyses suggest that avoidance of exposure to domestic allergens is a critical element in integrated strategies for both the prevention and the management of asthma. The promise of primary intervention in high-risk infants, as shown in the Isle of White study, has been confirmed in a recent study in Japan, and at least 4 similar trials are in progress… Recent studies with patients moved to high altitudes during seasonal reductions in mite exposure and randomized controlled interventions in houses have all shown improvements in clinical manifestations of asthma. These recent trials have also demonstrated something that was less certain—that massive reductions in domestic allergen exposure can be achieved and that people will adopt the significant changes to their domestic environment and lifestyles if the risks and benefits are known.
(J Allergy Clin Immunol 1999;103:179-91.)

RESEARCH: The role of intervention in established allergy: Avoidance of indoor allergens in the treatment of chronic allergic disease

Avoidance of exposure to indoor allergens is an important element in the treatment of allergic disease. The results of several studies provide strong evidence in support of a role for allergen avoidance… The greatest challenge is to educate allergic patients so that they can play an important role in controlling their own disease.
(J Allergy Clin Immunol 2000;106:787-804.)