T-cell epitopes of aeroallergens

Math-free guides for glycerin and allergens at variable subcutaneous injection volumes: How's my dosing? Update

BACKGROUND

Current summaries of effective maintenance dose ranges for subcutaneous immunotherapy (SCIT) are based on administration of 0.5-mL volumes. Extract formulations delivering equivalent dose ranges for practices using different injection volumes have not been reported, and calculation of the final glycerin concentrations in these solutions remains an inconvenient and repetitive process.

OBJECTIVE

To create math-free guides for allergen doses and glycerin concentrations that identify the extract concentrate volumes required to deliver doses within the ranges cited in the 2011 immunotherapy practice parameters for clinicians using 5.0-mL maintenance vials and injection volumes ranging from 0.2 to 1.0 mL.

METHODS

Algebraic calculations were performed to determine the specific combinations of extract concentrate strengths, volumes of these products in patient vaccines, and injection volumes needed for administration of target allergen doses spanning the current SCIT practice parameter recommendations.

RESULTS

For each product or group (nonstandardized extracts), tables were constructed to define the allergen doses provided by various combinations of extract concentrate volumes and injection volumes. The values within the effective dose ranges for each product were highlighted to facilitate comparisons of specific conditions relevant to allergy specialists. Glycerin tables were also created to permit convenient assessments of the final concentrations of this stabilizer in patient prescriptions.

CONCLUSION

SCIT dosing and glycerin tables are useful tools to assist allergists with practice decisions that involve variable patient formulas and injection volumes and can help identify suitable conditions for treatment of patients presenting with diverse allergen sensitivities and specificity profiles.

Allergen stabilities and compatibilities in immunotherapy mixtures that contain cat, dog, dust mite, and cockroach extracts

BACKGROUND

Indoor allergen mixtures that contain cat, dog, dust mite, and cockroach extracts are commonly used in allergy clinics for subcutaneous immunotherapy, but product-specific stabilities and mixing compatibilities in these complex patient formulas have not been determined.

OBJECTIVES

To assess the recoveries of cat, dog epithelia, dog dander, dust mite Dermatophagoides farinae, and cockroach mix allergen activities in 5 component mixtures and 1:10 (vol/vol) dilutions stored for up to 12 months.

METHODS

Concentrated stock mixtures, 10-fold dilutions of these mixtures in human serum albumin-saline diluent, and analogous single-extract controls were analyzed for major allergen concentrations (cat Fel d 1, dog dander Can f 1) and multiallergen IgE-binding potencies (dog epithelia, D farinae, cockroach mix) after storage for 3, 6, 9, and 12 months at 2°C to 8°C.

RESULTS

The selected immunoassays were specific for individual target extracts in the 5-component mixtures and exhibited analytical sensitivities sufficient for evaluation of both the concentrated and diluted indoor allergen formulas. All control samples except diluted cockroach extract had near-complete stabilities during refrigerated storage. Mixtures that contained cat, dog epithelia, dog dander, and D farinae extracts exhibited favorable mixing compatibilities in 1:1 (vol/vol) concentrates (47.5% glycerin) and 1:10 (vol/vol) dilutions (4.75% glycerin), relative to corresponding control sample reactivities. Cockroach allergens in both 1:1 (vol/vol) and 1:10 (vol/vol) concentrations were stabilized significantly by mixing with the other 4 indoor allergen extracts.

CONCLUSION

Extracts in mixtures that contained 5 common sources of indoor allergens possess favorable stabilities and mixing compatibilities and support the practice of combining these products in the same patient treatment formulations for subcutaneous immunotherapy.

Mixing compatibilities of Aspergillus and American cockroach allergens with other high-protease fungal and insect extracts

BACKGROUND

Recent studies have shown that Alternaria and German cockroach allergens can be degraded by endogenous proteases from other insect and fungal extracts when combined for immunotherapy, but data supporting the compatibilities of other high-protease products in comparable mixtures have not been reported.

OBJECTIVE

To assess the stabilities and compatibilities of Aspergillus fumigatus and American cockroach allergens after mixing with protease-rich extracts from other insects or fungi at concentrations similar to those recommended for subcutaneous immunotherapy.

METHODS

Mixtures containing A fumigatus, American cockroach, and other fungal or insect extracts were evaluated by quantitative (enzyme-linked immunosorbent assays) and qualitative (immunoblotting) methods. Test mixtures and control samples at 10% to 50% glycerin concentrations were analyzed after storage for up to 12 months at 2°C to 8°C.

RESULTS

Moderate to high recoveries of Aspergillus extract activities were retained in control samples and extract mixtures under all conditions examined. American cockroach extract controls were partly degraded at 10% to 25% glycerin, and cockroach allergen compatibilities were decreased significantly in mixtures with several fungal extracts at 25% glycerin. Mixing with other insects did not compromise the stability of American cockroach allergens at 25% to 50% glycerin.

CONCLUSION

Aspergillus extracts exhibited favorable stabilities after mixing with other high-protease products. American cockroach extract potencies were unstable in less than 50% glycerin, even in the absence of other protease-containing allergens, and were destabilized in mixtures with several fungal extracts. Addition of fungal and insect extracts to separate treatment vials or preparation of fungal-insect mixtures at elevated glycerin concentrations might be necessary to produce compatible patient formulations for allergen immunotherapy injections.