Mass spectrometry to complement standardization of house dust mite and other complex allergenic extracts

Abstract

In the United States, the Center for Biologics Evaluation and Research of the US Food and Drug Administration regulates biologics used for diagnosis and treatment of allergic diseases. The Code of Federal Regulations 21CFR680.3(e) states that when measured, the potency of an allergenic extract is assessed according to its allergenic activity. As of 2016, 19 allergenic extracts are standardized for potency in the United States. While these standardized extracts constitute a minority of those available, they treat the most prevalent allergies (e.g. grass and ragweed pollens, dust mites, and cat) and those that induce life-threatening anaphylaxis (e.g. Hymenoptera venom). Standardization for potency enhances safety and efficacy of immunotherapy by minimizing the risks of variations in allergen dosing when switching from one lot of manufactured extract to another, and by providing an objective measure of stability of each lot of allergenic extract over time. Allergenic extracts that have multiple immunodominant allergenic proteins are standardized with little or no information about compositional differences among extracts. Here, we propose application of mass spectrometry towards measurement of compositional differences among extracts that may affect the efficacy and safety of allergen immunotherapy. In addition, we discuss of house dust mite allergen extracts as a prototypical complex extract that may be standardized by mass spectrometry.

Allergen Extracts for In Vivo Diagnosis and Treatment of Allergy: Is There a Future?

“…They include, for example, mass spectrometry, circular dichroism, size exclusion that allows the detection of allergen peptides, and the analysis of the fold of proteins and of the aggregation behavior, respectively 97,98. In particular, mass spectrometry has been suggested as a powerful method for the standardization of allergen extracts 81,99,100. Although circular dichroism and gel filtration are very useful and suitable for the analysis of single purified molecules,101 these methods cannot be used for complex allergen mixtures.…”

“…There are methods that in principle allow us to analyze the aforementioned parameters for single molecules with sufficient accuracy. Mass spectrometry has recently been proposed as a method for the standardization of allergen extracts 81. However, mass spectrometry can only demonstrate the presence of certain allergen-derived peptides in an extract but is not a real quantitative method and cannot tell anything about the allergenic or immunogenic properties of the molecules 82.…”

Evaluation of major mite allergens from European standardized commercial extracts for in vivo diagnosis: addressing the need for precision medicine

“…Mass spectrometry (MS) has been used as a tool to identify novel allergens or to prove identity and enhance the quality control of recombinant allergens [47 ]. Spiric et al [48 ] suggest that a MS technique known as multiple reaction‐monitoring (MRM) may complement the overall potency measurements or quantitation of allergenic proteins by ELISA to inform practitioners of compositional differences among HDM reagents, and of variations in composition among lots from each manufacturer.…”

An evaluation of veterinary allergen extract content and resultant canine intradermal threshold concentrations

“…Allergen extracts are aqueous preparations produced from natural source materials that contain various amounts of major, minor and isoallergens, as well as other nonallergenic compounds . The efficacy of ASIT depends exclusively on the content of allergen preparations, and manufacturers are challenged to produce allergen extracts with consistent compositions.…”