Low Vitamin D3 (VD3) levels have been reported to be associated with the risk of allergic diseases like asthma. In addition, VD3 has been demonstrated in vitro, ex vivo (skin-explants) and in animal models to program the immune system towards anti-inflammatory immune responses, dominated by regulatory T-cells (Treg) producing Interleukin (IL)-10. In response to allergens, healthy individuals by default have such a protective immune response against innocuous allergens, whereas allergic subjects develop an inflammatory Th2-type response. VD3 co-administered with allergen may be a promising adjuvant to improve the onset and efficacy of allergen immunotherapy (AIT), by helping the allergic immune system to divert towards an allergen-specific response dominated by regulatory T cells (Treg) and IL-10. A clinical trial will be performed to compare the immune effects, the tolerability and safety of multiple doses of a VD3 analogue (Zemplar® 5 μg/ml - Abbvie, registered for the intravenous route) administered by the subcutaneous (s.c.) route in subjects with allergic rhinitis and healthy controls. Primary and secondary outcomes will be compared at baseline and at several time points during the study to investigate whether 1) the healthy controls at baseline have a more anti-inflammatory systemic cellular immune response to polyclonal stimuli and to allergens compared to birch pollen allergic subjects, and 2) whether s.c.VD3 analogue can skew these responses in allergic subjects towards a profile more resembling the one observed in healthy controls. The overall aim is to provide additional (in vivo) support for the use of VD3 as an adjuvant in allergen-specific immunotherapy, on top of the existing pre-clinical evidence demonstrating that antigen-presenting cells educate the adaptive immune system towards an anti-inflammatory response when allergen is seen in the presence of VD3.
Low Vitamin D3 (VD3) levels have been reported to be associated with the risk of allergic diseases like asthma. VD3 has been demonstrated in vitro, ex vivo and in animal models to program the immune system towards anti-inflammatory immune responses. VD3 co-administered with allergen may be a promising adjuvant to improve the onset and efficacy of allergen immunotherapy (AIT). A clinical trial will be performed to compare the immune effects, the tolerability and safety of multiple doses of aVD3 analogue (registered for the intravenous route) administered by the subcutaneous (s.c.) route in subjects with allergic rhinitis and healthy controls.~The overall aim is to provide additional (in vivo) support for the use of VD3 as an adjuvant in allergen-specific immunotherapy, on top of the existing pre-clinical evidence demonstrating that antigen-presenting cells educate the adaptive immune system towards an anti-inflammatory response when allergen is seen in the presence of VD3.