Molecular profile clustering of allergen-specific IgE responses and potential implications for specific immunotherapy

Recent data on molecular profiles of immunoglobulin E (IgE) sensitization in allergic patients facilitate the discussion of novel concepts of allergen specific immunotherapy. In childhood an IgE response to grass pollen starts preclinically as a weak, mono- or oligomolecular immune response evolving rapidly to become a strong, polymolecular sensitization with clinical manifestations. This immunological phenomenon, the increase of involved (allergenic) molecules during the course of sensitization, has been termed "molecular spreading". It explains why subsequent allergen-specific IgE-profiles to complex allergen sources are highly heterogeneous in the population. Recently published findings from a birth cohort study raise new questions: do different molecular sensitization profiles (e.g. to grass pollen allergens) lead to different clinical responses to allergen-specific immunotherapy? Should the allergen-specific immunological intervention be anticipated at earlier stages of the IgE sensitization process? Should the design and production of molecularly defined allergen-specific immunotherapy preparations consider more the extreme heterogeneity of sensitization profiles in atopic individuals? These questions can only be addressed by carefully planned clinical studies. The results might potentially improve our future options for specific immune prophylactic measures and early immunotherapy.