title: The biological potency of different extracts for sublingual immunotherapy assessed by skin prick tests.
abstract: The standardization of allergen extracts is of primary relevance to the clinical efficacy. Biological standardization procedures are widely used in the commercial production of vaccines. We tested, in grass-allergic patients, the potency of three different grass extracts for sublingual immunotherapy by means of skin prick tests. Specific IgE against Phl p 1, 2, 4, 5, 7, 11 and 12 were also assayed. Allerslit and Sublivac were directly applied as skin test. Grazax, was prepared by dissolving two tablets in 2 mL saline. Thirty-three subjects (mean age 38.8) were studied. The skin response was significantly different among extracts, decreasing from Allerslit to Grazax (t test < 0.01), but all the extract produced a skin response greater than histamine. All the subjects had specific IgE to Phl p 1 and Phl p 4 but 24% did not have specific IgE to Phl p 5. In those subjects the skin response to the three extracts did not differ from that of Phl p 5-positive subjects. Our findings confirm that there is a variability in the biological potency among different extracts. In addition, the standardization of grass extracts based on Phlp 5 only, may be insufficient in some cases.
authors.affiliation: Allergy Unit, National Health Service, Rete di Allergologia Regione Piemonte, Cuneo 1, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Rossi
authors.forename: G
authors.initials: G
authors.lastname: Monasterolo
authors.forename: G
authors.initials: G
authors.lastname: Passalacqua
mesh_terms: D000286:Administration, Sublingual; D000293:Adolescent; D000328:Adult; D002648:Child; D003888:Desensitization, Immunologic; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000276:immunology*; D006109:Poaceae / Q000276:immunology*; D012882:Skin Tests
chemical_list: D010936:Plant Extracts; D007073:Immunoglobulin E