Fungal raw materials used to produce allergen extracts.

OBJECTIVE To review the topic of fungal raw materials used for the production of allergen extracts and the associated challenges and highlight candidate areas for development before standardized fungal allergen extracts can be commercially produced. DATA SOURCES A PubMed search was performed using focused keywords and combined with a review of regulatory documents and industry guidelines. Several books on mycology also were consulted. STUDY SELECTIONS The information obtained through the literature, books, and industry was scrutinized and combined with personal experience and expertise to write this article. RESULTS Fungi are complex ubiquitous organisms on Earth. They are beneficial and detrimental for humans. Fungi can cause hypersensitivity reactions, including types I, III, and IV. The procurement of fungal raw materials to prepare allergen extracts for diagnosis and possible allergen immunotherapy is complex owing to the intrinsic nature of fungi and their complex genome. Allergen manufacturers produce allergen extracts with variable qualitative and quantitative compositions, which can lead to unpredictable clinical outcomes. CONCLUSION The clinician should be aware of the factors responsible for the qualitative and quantitative compositions of fungal allergen extracts and the reasons that currently preclude their standardization. Scientific advances and collaboration and cooperation between allergen manufacturing companies and regulatory agencies are necessary to improve the quality and consistency of fungal extracts. Moreover, clinicians should understand the limitations of currently available fungal extracts.