Allergen immunotherapy is effective in patients with IgE-dependent allergic rhinitis and asthma. When immunotherapy is given continuously for 3 years, there is persistent clinical benefit for several years after its discontinuation.
Clinical improvement is accompanied by decreases in numbers of effector cells in target organs, including:
- mast cells
- type 2 innate lymphoid cells
Mechanisms of allergen-specific immunotherapy (click to enlarge the image). The diagram is based on: Mechanisms of allergen-specific immunotherapy. Akdis CA, Akdis M. J Allergy Clin Immunol. 2011 Jan;127(1):18-27.
Immunotherapy results in:
- production of blocking IgG/IgG4 antibodies that can inhibit IgE-dependent activation mediated through both high-affinity IgE receptors (FcεRI) on mast cells and basophils and low-affinity IgE receptors (FcεRII) on B cells
- suppression of TH2 immunity can occur as a consequence of either deletion or anergy of antigen-specific T cells
- induction of antigen-specific regulatory T cells
- immune deviation in favor of TH1 responses.
It is not clear whether the altered long-term memory resides within the T-cell or the B-cell compartment. Recent data highlight the role of IL-10-producing regulatory B cells and "protective" antibodies that likely contribute to long-term tolerance.
Mechanisms of allergen immunotherapy for inhaled allergens and predictive biomarkers. - JACI 2017 - PubMed - NCBI http://bit.ly/2m5VEII