Efficacy, safety, and immunological effects of a 2-year immunotherapy with Depigoid® birch pollen extract: a randomized, double-blind, placebo-controlled study

• Published in: Clinical and experimental allergy 2010-07, Vol.40 (7), p.1062-1070
• Main Authors: Höiby, A.-S., Strand, V., Robinson, D.S., Sager, A., Rak, S.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Allergic; Betula; Betula - immunology; Biological and medical sciences; birch pollen; blood; chemistry; Child; depigmented polymerized allergen extract; Double-Blind Method; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Immunoglobulin E; Immunoglobulin E - blood; Immunologi inom det medicinska området; immunology; Immunology in the medical area; Immunotherapy; Immunotherapy - standards; Infusions; Infusions, Subcutaneous; Male; Middle Aged; Plant Extracts; Plant Extracts - chemistry; Plant Extracts - immunology; Pollen; Pollen - immunology; Rhinitis; Rhinitis, Allergic, Seasonal - immunology; Rhinitis, Allergic, Seasonal - therapy; Seasonal; specific immunotherapy; Subcutaneous; therapy
• ISSN: 0954-7894; 1365-2222; 1365-2222
• DOI: 10.1111/j.1365-2222.2010.03521.x

Summary Background Rhinoconjunctivitis due to birch pollen sensitization is common in Northern Europe. A depigmented polymerized birch pollen extract – Depigoid® has been developed for immunotherapy. Objective To evaluate its clinical efficacy, safety, and effects on immunological parameters. Methods Sixty‐one patients aged 7–69 years were included in a randomized, double‐blind, placebo‐controlled trial of subcutaneous immunotherapy (SCIT) using depigmented polymerized birch pollen extract. SCIT consisted of four increasing doses at 7‐day intervals, followed by maintenance injections of 500 DPP (corresponding to 30 μg Bet v1 before depigmentation) at 6‐week intervals for 18 months. The primary outcome was the combined symptom and medication score during the 2006 birch pollen season. The frequency of peripheral blood mononuclear cells (PBMC)producing IL‐4, IL‐10, IL‐12, and IL‐13 was assessed in a subgroup of patients by ELISPOT assay. Results After 18 months of treatment, the median combined symptom and medication score (upper/lower quartile) of treated patients was significantly lower than those on placebo: 8.0 (5.8–10.3) and 12.6 (8.6–16.2), respectively (P=0.004). Systemic reactions occurred in 29 patients (12 active, 17 placebo), were grades 1 or 2, and none required specific treatment. After 18 months of treatment, mean serum concentrations of specific IgE increased significantly in both groups (P