Immunotherapy with a Phleum pratense allergen extract induces an immune response to a grass-mix allergen extract

Background: grass pollen allergy is one of the most common allergies worldwide,and patients often show sensitization to an array of phylogenetically related species. objective: to determine the effect of specific immunotherapy (sit) with phleum pratense extract on induction of the immune response to a mixture composed of 5 grass pollen extracts. methods: forty-six adult patients suffering from rhinitis and sensitized to a mix of grass pollen allergen extracts were randomized 3:1 to receive a short course of sit with p pratense or to an open control group without sit. at baseline and after 3-4 months,we evaluated levels of specific immunoglobulin (ig) e and igg4,as well as the immediate and delayed cutaneous responses to the grass mix and p pratense. igg4 to lolium perenne was also determined. results: levels of ige and igg4 to grass mix and p pratense increased significantly during treatment (p<.001). however,this increase was only significantly higher in the sit group than in the control group for igg4 (p<.001). the levels of igg4 to phl p 5 and lol p 5 were highly correlated (r=0.99,p<.001). the immediate and delayed cutaneous responses were significantly diminished to both extracts after sit (p<.001). conclusions: patients with rhinoconjunctivitis diagnosed using skin prick testing with a grass mix allergen extract and treated with a short course of sit based on a single species p pratense allergen extract are able to develop an immune response that targets not only the immunizing species,but also the grass mix allergen extract. © 2010 esmon publicidad.