Allergen-specific immunotherapy and risk of autoimmune disease

After 100 years of experience with allergen-specific immunotherapy (SIT), an issue that is still unresolved is whether SIT can act as a trigger of, or as a risk factor for, autoimmune disease. We searched the literature for evidence on this topic.

Several case reports of autoimmune disease development with plausible relation to SIT have been published. Vasculitis reactions accounted for the majority of case reports retrieved in our literature search. Whether the number of reported cases is higher or lower than what would be expected by chance is not possible to determine from existing data. There are no published data on autoimmune disease development in patients participating in randomized trials of the effects of SIT. One nonrandomized pharmacoepidemiological study did not detect an increased risk of autoimmune disease development during SIT as compared with the risk during conventional allergy treatment.

In conclusion, development of autoimmune disease in allergic patients treated with SIT is rare. Nevertheless, as a principle of caution, it seems reasonable to carefully evaluate the indication for SIT, that is, risks versus benefits, in patients with established autoimmune disease or a strong family history of autoimmune disease.