Aluminum sulfate significantly reduces the skin test response to common allergens in sensitized patients

Abstract

Background: Avoidance of allergens is still recommended as the first and best way to prevent allergic illnesses and their comorbid diseases. Despite a variety of attempts there has been very limited success in the area of environmental control of allergic disease. Our objective was to identify a non-invasive, non-pharmacological method to reduce indoor allergen loads in atopic persons' homes and public environments. We employed a novel in vivo approach to examine the possibility of using aluminum sulfate to control environmental allergens.

Methods: Fifty skin test reactive patients were simultaneously skin tested with conventional test materials and the actions of the protein/glycoprotein modifier, aluminum sulfate. Common allergens, dog, cat, dust mite, Alternaria, and cockroach were used in the study.

Results: Skin test reactivity was significantly reduced by the modifier aluminum sulfate. Our studies demonstrate that the effects of histamine were not affected by the presence of aluminum sulfate. In fact, skin test reactivity was reduced independent of whether aluminum sulfate was present in the allergen test material or removed prior to testing, indicating that the allergens had in some way been inactivated.

Conclusion: Aluminum sulfate was found to reduce the in vivo allergic reaction cascade induced by skin testing with common allergens. The exact mechanism is not clear but appears to involve the alteration of IgE-binding epitopes on the allergen. Our results indicate that it may be possible to diminish the allergenicity of an environment by application of the active agent aluminum sulfate, thus producing environmental control without complete removal of the allergen.

Figure 1

Selected patients were skin tested with allergens mixed with AS. Controls included allergens alone and saline. Means and standard deviations, as well as P-values, of data (clinical scores, see Methods) collected from the 50 patients are presented. P-values were determined using an unpaired two-tailed Student's t-test. A P-value of < 0.05 was considered statistically significant. Notice that AS markedly reduced skin test reactions to the allergens tested.

Figure 2

Wheal and flare responses in a patient skin tested with the cat allergen and cat allergen mixed with AS, as in Figure 1. Histamine and saline were included as controls. Reactions were read with no testing (A), 5 min (B), 15 min (C), and 30 min (D). Within each panel, skin prick responses are shown to: histamine (1), saline (2), 10% saline + 90% cat allergen (3), cat allergen (4), and 10% ASβ + 90% cat allergen (5). Wheals were measure by the aid of skin test calipers.

Figure 3

Aluminum sulfate does not block histamine. Skin reactions at 15 min are shown in panel (A). Skin reactions at 30 min are shown in panel (B). Within panels A and B, skin prick responses are shown to: saline (1), histamine (2), 0.9% AS (3), 9.0% AS (4), 0.9% AS + histamine (1.8 mg/ml) mixed at 1:10 (AS:histamine) (5), and 9.0% AS + histamine (1.8 mg/ml) mixed at 1:10 (AS:histamine) (6). Skin reaction to 0.1 cc AS ID at 15 min is shown in panel (C) (site 7). Skin reaction 15 min following overlay of site 7 in panel C with histamine (1.8 mg/ml) is shown in panel (D). Notice that AS did not inhibit the histamine induced skin reaction.

Figure 4

Exposure to aluminum sulfate alters the allergen. Skin test results of three patients after 30 min are shown. Sample 1 contains cat allergen and water which was dialyzed against water and thus acts as a positive control. Sample 2 includes cat allergen and AS which was dialyzed against AS, thus the test sample contains AS. Sample 3 is cat allergen and AS which was dialyzed against water, therefore the test sample does not contain AS. Water and AS controls are also shown (samples 4 and 5 respectively). Representative photograph (patient 3) of skin test response after 30 min is also shown.