The overall effect of these changes is to reduce PLX 4720 the inflammatory response in the target tissue. This was shown as a marked seasonal reduction in mucosal eosinophil recruitment and an increase in IFN-γ and IL-10 production in nasal mucosal biopsy samples after hay fever immunotherapy [126].

Many of the mechanisms described for conventional weekly up-dosing regimens of immunotherapy cannot apply to the initial phase of rush desensitization, where tolerance is induced within days. While the changes described above may eventually supervene, the initial rapid induction of tolerance to the allergen is likely to represent tachyphylaxis, where repeated doses of allergen induce a progressively weaker mediator response. Changes in histamine release, cytokine production by T cells and monocytes and even antibody binding activity have been described within the first days of rush immunotherapy. The tolerant state is maintained by continued administration of allergen, and a long-lasting immune tolerance develops as maintenance therapy continues. Allergen immunotherapy is a unique treatment, one of only a few that can truly be said to fundamentally alter a disease BIBW2992 clinical trial state. Therefore,

we approach advances in immunotherapy with caution: what can we improve without losing the core benefits? Clearly, we focus on the disadvantages of standard subcutaneous immunotherapy. It is time-consuming both in frequency of treatments and total duration of therapy, it needs to be administered by trained professionals (and is therefore expensive), it requires injections, which are not acceptable to all patients and it is potentially life-threatening. These factors severely restrict the number of individuals who can take advantage of this treatment. If we are to realize the tantalizing

prospect of altering the natural history of allergy in a substantial proportion of allergy patients, and even in the population as a whole, then immunotherapy will need to be dramatically different from what is used routinely today. Allergens extracted from their natural source have been in routine use since the inception Tenofovir solubility dmso of SCIT. Standardization of the potency of these biologically variable products represented a major advance and has led to improved safety and efficacy. Various modifications of the allergen have been attempted to increase potency and specificity and to reduce the risk of acute reactions. Allergoid production by formaldehyde treatment of native antigen has long been used, but is associated with reduced efficacy in allergen immunotherapy. Short peptides, unable to cross-link IgE and induce mast cell degranulation, but able to activate T cells through presentation on human leucocyte antigen (HLA) class II, were shown to induce Th1 reactivity.