We induced in allergic humans the counterpart of murine experimental T- cell tolerance. T-cell lines from cat-allergic humans were used to map T- cell epitopes for the principal allergen of cat dander, Fel d 1. Two peptides of 27 amino acids each were synthesized to contain the dominant epitopes (ALLERVAX® CAT). After a safety trial, we carried out a blinded study of the dose required for efficacy. We randomly divided 95 cat- sensitive patients into placebo, 7.5 μg, 75 μg, and 750 μg groups. Patients received a subcutaneous injection weekly for 4 wk. Before and after treatment, patients were exposed in a room inhabited by live cats and scored by nose and lung symptoms. Baseline nasal and lung scores (± SEM) were 6.2 ± 0.56 and 5.4 ± 0.73 in the 750 μg group; 7.8 ± 0.53 and 4.7 ± 0.68 in the placebo group. Six weeks after treatment, scores adjusted for baseline differences were reduced in the 750 μg group: -2.3 ± 4.9 and -2.3 ± 0.59 compared with -0.84 ± 0.50 and -0.85 ± 0.62 in the placebo group. The 75 μg group showed intermediate effects and the 7.5 μg group no effect. Linear trend analysis indicated a significant close response effect: p = 0.05 for nose and 0.03 for lung symptoms. Allergic side effects occurred an hour or more after the first 750 μg dose in 16 of 24 patients but required little or no treatment with one exception. T-cell reactive treatment peptides safely improved allergic responses to cats.
|Original language||English (US)|
|Number of pages||6|
|Journal||American journal of respiratory and critical care medicine|
|State||Published - 1996|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine