Mechanisims of asthma and allergic disease – 1085. Safety and tolerability of escalating doses of house dust mite peptide antigen desensitisation

Methods Potential T-cell epitopes were identified by algorithm, screened for ability to stimulate T-cell responses in exvivo blood samples from HDM allergic subjects and tested to confirm they did not cause basophil histamine release. A second group of HDM allergic subjects attended a challenge where Conjunctival Provocation Test (CPT) response and Early (EPSR) and Late Phase Skin Response (LPSR) were measured. Subjects were randomised to one of 5 cohorts of 10 subjects. In each cohort 8 subjects received HDM peptide antigen desensitisation (PAD) using the identified T-cell epitope mixture and 2 subjects received placebo. The first cohort received 4x0.03nmol 4weeks(wk) apart; successive cohorts received 4 administrations 4wk apart of 0.3, 1, 3 and 12nmol, respectively. EPSR, LPSR and CPT were re-measured 18-22wk after starting treatment.