IgE-mediated allergy can be treated by subcutaneous allergen-specific immunotherapy (SCIT). However, the percentage of allergic patients undergoing SCIT is low, mainly due to the long duration of the therapy and the risk of systemic allergic reactions associated with SCIT.
To improve the safety and attractiveness of SIT for patients, alternative routes of allergen administration are being explored:
- sublingual (SLIT)
The present study (done in mice, not humans) evaluated direct intralymphatic allergen administration with bee venom and cat fur allergens.
A lymph node showing afferent and efferent lymphatic vessels. Image source: Wikipedia, public domain.
Direct injection of the major bee venom allergen phospholipase A(2) or the major cat fur allergen Fel d 1 into inguinal lymph nodes were compared with subcutaneous injections.
Only intralymphatic immunisation stimulated the production of the Th1-dependent subclass IgG2a, which is associated with improved protection against allergen-induced anaphylaxis.
The authors concluded that in this mouse model, intralymphatic immunisation induced more than 10-fold higher IgG2a responses with 100-fold lower allergen doses than subcutaneous immunisation.
Intralymphatic Injections as a New Administration Route for Allergen-Specific Immunotherapy. Martínez-Gómez JM, Johansen P, Erdmann I, Senti G, Crameri R, Kündig TM. Int Arch Allergy Immunol. 2009 Apr 2;150(1):59-65. [Epub ahead of print]