Safe and Effective Immunotherapy for Allergy to Common Fungus

Subcutaneous allergen immunotherapy has been demonstrated to be a safe and effective treatment for individuals allergic to a common fungus.

Alternaria alternata on a Nicotiana tabacum leaf. Source: USDA Forest Service

People allergic to the common fungus Alternaria alternata may now be able to re-educate their immune system via an immunotherapy to prevent unwanted allergic responses and avoid debilitating symptoms.

This common fungus is frequently found in households and gardens and causes burdensome symptoms such as itching of the eyes or nose, sneezing, red eyes, and nasal congestion in sensitized individuals, who carry an expanded population of white blood cells capable of responding to components of the fungus. Following inhalation or contact with fungal allergens, allergen-specific B cells and their plasma cell progeny mount an immune response leading to allergy symptoms and the production of a particular subclass of allergy-related blood-borne proteins that confer long lasting anti-fungal immunity but also chronic allergy.

Researchers investigated whether the repeated deliberate exposure of allergic individuals to the major fungal allergen “Alt a 1” could reduce immune sensitivity and the severity of allergy symptoms. Different quantities of “Alt A 1” or a placebo were injected beneath the skin of patients with allergic rhinoconjunctivitis between the ages of 12 and 65.

This double-blind, randomized, placebo-controlled trial showed that the severity of symptoms and use of allergy medications greatly decreased for patients that received the allergen immunotherapy for 12 months. The skin of patients demonstrated reduced reactivity to contact with the fungus and damaging allergy-associated IgE antibody was replaced with antibody of the non-allergy-associated subclass IgG4. Overall, this immunotherapy was demonstrated to be safe and effective, and may represent a new treatment option for patients with debilitating allergies to this common fungus.

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Tabar AI, Prieto L, Alba P, et al. (2019) Double-blind, randomised, placebo-controlled trial of allergen-specific immunotherapy with major allergen Alt a 1. The Journal of Allergy and Clinical Immunology, pii: S0091-6749(19)30350-1.