To assess the efficacy of peptide-based immunotherapy (PIT) on rhinitis outcomes in cat-allergic subjects.

Cat allergic subjects were recruited into a single blind study with 16 subjects randomized to receive 12 peptides (incremental dosing protocol with fortnightly intradermal injections) to a total dose of 291 μg of each peptide. Eight subjects received diluent. The change in nasal and cutaneous reactivity was assessed before and 3 months after PIT. Nasal reactivity was measured as the change in baseline for nasal blockage (scale 0-3), nasal inspiratory flow rate (NIFR), number of sneezes and weight of nasal secretion after installation of whole cat allergen extract in each nostril. Measurements were made for the first 15 min and at 60 min. Skin reactions were recorded at 15 min (early phase reaction; EPR) and at 6 hr (late phase reaction; LPR) after diluent and whole cat dander intradermal challenge.

Following PIT there was a significant reduction at 15 min, in allergen-induced nasal blockage compared to diluent (p=0.006), in the number of sneezes (p=0.04) and in the weight of secretions (p=0.04). There was no effect of PIT on the allergen induced NIFR at 15 min or 60 min or on nasal blockage, sneezes or secretions at 60 min. PIT resulted in a reduction in the cutaneous LPR (allergen challenge vs. diluent; p=0.03). There was no effect on the EPR. PIT was well tolerated with no systemic adverse events.

T cell peptide therapy may be useful in the management of allergic rhinitis.