Intradermal Grass Pollen Allergen Immunotherapy for Seasonal Allergy: A Randomized Controlled Trial

Publication date: Available online 20 October 2016
Source:Journal of Allergy and Clinical Immunology
Author(s): Anna Slovick, Abdel Douiri, Rachel Muir, Andrea Guerra, Konstantinos Tsioulos, Evie Hay, Emily P.S. Lam, Joanna Kelly, Janet L. Peacock, Sun Ying, Mohamed H. Shamji, David J. Cousins, Stephen R. Durham, Stephen J. Till
BackgroundRepeated low dose grass pollen intradermal allergen injection suppresses allergen-induced cutaneous late phase responses, comparable with conventional subcutaneous and sublingual immunotherapy.ObjectiveTo evaluate the efficacy and safety of grass pollen intradermal immunotherapy in the treatment of allergic rhinitis.MethodsWe randomly assigned 93 adults with grass pollen allergic rhinitis to receive 7 pre-seasonal intradermal allergen injections (containing 7 nanograms of Phl p 5 major allergen) or histamine control. The primary endpoint was daily combined symptom-medication scores during the 2013 pollen season (area under curve). Analysis was by intention-to-treat. Skin biopsies were collected following intradermal allergen challenges and late phase responses measured four and seven, ten or thirteen months post-treatment.ResultsThere was no significant difference in primary endpoint between treatment arms (active n=46, control n=47, median difference, 14; 95% CI -172.5-215.1; P=.80). Among secondary endpoints, nasal symptoms were worse in the intradermal treatment group, measured by daily scores (median difference, 35; 95% CI 4.0-67.5; P=.03) and visual-analog scales (median difference, 53; 95% CI -11.6-125·2; P=.05). In a per protocol analysis, intradermal immunotherapy was further associated with worse asthma symptoms and fewer symptom free days. Intradermal immunotherapy increased serum Phl p-specific IgE (P=.001) compared to the control arm. T cells cultured from biopsies of intradermal immunotherapy subjects showed higher expression of Th2 surface marker CRTH2 (P=.04) and lower Th1 marker CXCR (P=.01), respectively. Late phase responses remained inhibited seven months after treatment (P=.03).ConclusionIntradermal allergen immunotherapy suppressed skin late responses but was not clinically effective and resulted in worsening of respiratory allergic symptoms.

Teaser

Grass pollen intradermal allergen immunotherapy was not clinically effective, but worsened seasonal allergic rhinitis symptoms with implications for novel immunotherapy that targets allergen delivery to the skin.


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