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Standardization of Chortoglyphus Arcuatus Allergenic Extract. Determination of Biological Activity in HEP Units

This study has been completed.
Information provided by:
Laboratorios Leti, S.L. Identifier:
First received: July 17, 2008
Last updated: August 4, 2010
Last verified: August 2010
The main purpose of the trial is to prove the therapeutic value of the product and enable an effective and safe dosage schedule to be recommended

Condition Intervention Phase
Rhinitis, Allergic, Seasonal Conjunctivitis, Allergic Other: Standardization of allergenic extract (Ch. arcuatus) Phase 2

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: None (Open Label)
Official Title: Standardization of Chortoglyphus Arcuatus Allergenic Extract. Determination of Biological Activity in HEP Units

Further study details as provided by Laboratorios Leti, S.L.:

Primary Outcome Measures:
  • Wheal size area (mm2) of the immediate phase reaction. [ Time Frame: 30 minutes per subject ]

Enrollment: 30
Study Start Date: June 2008
Study Completion Date: November 2008
Primary Completion Date: November 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: A
In each individual patient, 10 mg/ml histamine dihydrochloride solution and a phenolated saline solution will be applied as positive and negative control respectively.
Other: Standardization of allergenic extract (Ch. arcuatus)
Allergenic extract for cutaneous prick-test

Detailed Description:
The skin testing procedure, based on the Nordic Guidelines is the reference method for the biological calibration of in-House Reference Preparations (IHRP). The method is not intended for routine testing of allergen extracts. The use of this procedure is the basis for the definition of biological activity units: "the activity of an allergen extract is 10,000 Biological Units (BU) per ml (10 HEP per ml), when the extract provokes an specific skin reaction in the median sensitive patient with a wheal of the same size as a wheal provoked by a positive reference solution consisting of histamine 54.3 mmol/l (for example histamine dihydrochloride 10 mg/ml), when both solutions are administrated using the same technique (prick testing) on at least 20 individuals who are clinically allergic and cutaneously reactive to the allergen concerned".

Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Voluntarily signed informed consent form by the patient
  • Patients should live in a geographic zone where allergy caused by Chortoglyphus arcuatus is a relevant problem.
  • Patients should not be excluded due to low or high sensitivity to the allergen, when they otherwise fulfil the inclusion criteria.
  • A positive case history with inhalant allergy related to exposure to the allergen to be tested.
  • A positive prick test (mean wheal diameter > 3 mm) when tested with a standardized extract prepared from the allergen source in question and/or a positive test for specific IgE.
  • A mean wheal diameter > 7 mm2 obtained in a prick test with histamine dihydrochloride 10 mg/ml.
  • Age: 18-50 years.
  • Both genders

Exclusion Criteria:

  • Immunotherapy in the past 2 years with an allergen preparation known to interfere with the allergens to be tested.
  • Use of drugs that may interfere with the skin reactions.
  • Pregnancy
  • Dermographism
  • Atopic dermatitis (locally at the test site)
  • Urticaria.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00718744

Hospital "Xeral de Calde"
Calde, Lugo, Spain, 27004
Sponsors and Collaborators
Laboratorios Leti, S.L.
Principal Investigator: Manuel Boquete, MD
  More Information

Responsible Party: María José Gómez, Laboratorios LETI S.L.Unipersonal Identifier: NCT00718744     History of Changes
Other Study ID Numbers: 2005-001194-96
Study First Received: July 17, 2008
Last Updated: August 4, 2010

Keywords provided by Laboratorios Leti, S.L.:

Additional relevant MeSH terms:
Rhinitis, Allergic
Rhinitis, Allergic, Seasonal
Conjunctivitis, Allergic
Nose Diseases
Respiratory Tract Diseases
Respiratory Tract Infections
Otorhinolaryngologic Diseases
Conjunctival Diseases
Eye Diseases
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases processed this record on August 18, 2017