Potential effect of the administration of substance P and allergen therapyon immunoglobulin E-mediated allergic reactions in human subjects

Previously we observed and reported that immunoglobulin E-mediated (IgE-med iated) allergy in rhesus monkeys was decreased by the administration of sub stance P (SP) and an allergen. We extended these studies to human subjects, giving SP and 1 allergen to subjects with reactivity to more than 1 allerg en, using reactivity to a second allergen as a control. SP and an allergen were initially given by aerosol delivery but subsequently were given by inj ection, The administration of SP and 1 allergen by aerosol delivery or inje ction resulted in decreased IgE-mediated reactivity to the allergen adminis tered and also to the control allergen. This result occurred in 7 of 8 huma n subjects. The 2 initial subjects receiving 8 SP and allergen injections h ad a sharp reduction in their symptoms of ragweed hay fever lasting for 3 y ears to date. No significant reactions to the injection of SP occurred. Fur ther controlled human research is necessary on the administration of SP and allergen and the mechanisms of action. Unexpected and serendipitous result s first observed in rhesus monkeys and reproduced in allergic human subject s provide a new and potential mechanism for control and perhaps obliteratio n of common IgE-mediated allergies and even more-serious allergic problems.