New routes and formulations for allergen-specific immunotherapy

Nonanaphylactic synthetic peptides derived from B cell epitopes of the major grass pollen allergen, Phl p 1, for allergy vaccination

Worldwide more than 200 million individuals are allergic to group 1 grass pollen allergens. We have used the major timothy grass pollen allergen Phl p 1, which cross-reacts with most grass-, corn-, and monocot-derived group 1 allergens to develop a generally applicable strategy for the production of hypoallergenic allergy vaccines. On the basis of the experimentally determined B cell epitopes of Phl p 1, we have synthesized five synthetic peptides. These peptides are derived from the major Phl p 1 IgE epitopes and were between 28-32 amino acids long. We demonstrate by nuclear magnetic resonance that the peptides exhibit no secondary and tertiary structure and accordingly failed to bind IgE antibodies from grass pollen allergic patients. The five peptides, as well as an equimolar mixture thereof, lacked allergenic activity as demonstrated by basophil histamine release and skin test experiments in grass pollen allergic patients. When used as immunogens in mice and rabbits, the peptides induced protective IgG antibodies, which recognized the complete Phl p 1 wild-type allergen and group 1 allergens from other grass species. Moreover, peptide-induced antibodies inhibited the binding of grass pollen allergic patients IgE antibodies to the wild-type allergen. We thus demonstrate that synthetic hypoallergenic peptides derived from B cell epitopes of major allergens represent safe vaccine candidates for the treatment of IgE- mediated allergies.

Sublingual immunotherapy: a double-blind, placebo-controlled trial with Parietaria judaica extract standardized in mass units in patients with rhinoconjunctivitis, asthma, or both

BACKGROUND

New routes of administering immunotherapy in respiratory allergy are being studied as an alternative to conventional injective immunotherapy. We carried out a study to evaluate the clinical efficacy and effects of sublingual immunotherapy in patients with Parietaria judaica-induced respiratory allergy.

METHODS

A double-blind, placebo-controlled design was followed. Thirty patients with P. judaica rhinoconjunctivitis, mild asthma, or both were randomly chosen for sublingual immunotherapy (14 patients) or placebo treatment (16 patients). The patients underwent preseasonal rush induction treatment followed by coseasonal maintenance treatment during the Parietaria pollen season. Symptom and drug scores, as well as specific IgE and specific IgG4, were recorded.

RESULTS

Significantly lower symptom and drug scores were found (P=0.04), especially during the Parietaria pollination period, in the immunotherapy group. No significant difference in specific IgE and specific IgG4 was detected between the active and placebo groups; a statistically significant increase of specific IgE was detected in both groups (P=0.05). No patient undergoing active sublingual immunotherapy reported local or systemic side-effects.

CONCLUSIONS

Our data suggest that sublingual immunotherapy is both clinically effective and safe in treating patients with Parietaria-induced rhinoconjunctivitis and mild asthma.