biological standardization of platanus acerifolia allergen extract

Conditions: Allergy to Platanus Acerifolia

Summary: the objective of this study is to determine the biologic activity of a platanus acerifolia allergen extract in histamine equivalent prick (hep) units, in order to be used as in-house reference preparation (ihrp).

this is an open, unblinded and non-randomized biological assay. the study design is a slight modification of the recommendations proposed by the nordic guidelines. four concentrations of platanus acerifolia allergen extract, together with a positive and negative control, using 10 mg/ml histamine dihydrochloride solution and a glycerinated phenol saline solution, respectively, will be tested in every patient in duplicate on the volar surface of the forearm.

Eligibility criteria:
inclusion criteria: * subject has provided written informed consent, appropriately signed and dated by the subject (or legal representative, if applicable). * subject can be male or female of any race and ethnic group. * age \> and =18 years and \< and =60 years at the study inclusion day. * positive skin prick test with a standardized commercially available preparation of platanus acerifolia allergen extract. the skin prick test will be considered positive if the test results in a wheal major diameter of at least 3 mm or an area at least 7 mm2. positive skin prick test results are valid if performed within one year prior to the inclusion of the subject in the study * a positive test for specific ige to platanus acerifolia (cap-rast major or equal to 2). ige results are valid if performed within oneyear prior to the inclusion of the subject in the study. * allergic symptoms during the pollen season of platanus acerifolia. * medical history positive allergy inhalation (rhinitis and /or rhinoconjunctivitis and/or asthma) from platanus acerifolia. exclusion criteria: * immunotherapy in the past 5 years with an allergen preparation known to interfere with the allergen to be tested due to a high degree of cross-reactivity (for example:other species of platanus: platanus orientalis, platanus occidentalis). * use of drugs that may interfere with the skin reactions (e.g., antihistamines). see appendix 1 of the protocol. * treatment with any of the following medications: oral tricyclic or tetracyclic antidepressants or imaos, beta-blockers, chronic use of corticosteroids or use of oral or parenteral corticosteroids in repeated and intermittent patterns (10 mg/daily of prednisone or equivalent). * women who are pregnant or period of breastfeeding and women with a pregnancy test positive during the visit 2, prior to the prick test. * dermographism affecting the skin area at the test site at either study visit. * atopic dermatitis affecting the skin area at the test site at either study visit. * urticaria affecting the skin area at the test site at either study visit. * diseases of the immune system relevant clinically, both autoimmune and immunodeficiencies. * serious diseases not controlled that may increase the risk for the safety of the subjects involved in this study, including, but not limited to the following: heart failure, uncontrolled or severe respiratory diseases,endocrine diseases, clinically relevant kidney or liver diseases or hematological diseases. * participation in any other clinical trial within 30 days (or 5 times the biological half-life of the research of the study product, whichever is longer) prior to the inclusion of the subject in this clinical trial. * patients with diseases or conditions that limit the use of adrenaline (heart disease, severe hypertension, ..) * severe psychiatric, psychological or neurological disorders * abuse of alcohol, drugs or medicines in the previous year.

Keywords: skin prick test inmunotherapy standarization