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Glycyphagus Domesticus Allergen Extract. Determination of the in Vivo Biological Activity in Histamine Equivalent Units (HEP).

This study has been completed.
Information provided by:
Laboratorios Leti, S.L. Identifier:
First received: June 8, 2009
Last updated: June 17, 2011
Last verified: June 2011
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 (Gly. domesticus) Phase 2

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Glycyphagus Domesticus Allergen Extract. Determination of the in Vivo Biological Activity in Histamine Equivalent Units (HEP).

Resource links provided by NLM:

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

Primary Outcome Measures:
  • Wheal size area (mm2) on the skin at the site of the puncture during the immediate phase. [ Time Frame: 45 minutes per subject ]

Enrollment: 27
Study Start Date: May 2009
Study Completion Date: July 2010
Primary Completion Date: May 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: A
Four concentrations of Glycyphagus domesticus allergen extract, together with a positive and negative control, using 10 mg/ml histamine dihydrochloride solution and a glycerinated phenol saline solution, respectively, was tested in every patient in duplicate on the volar surface of the forearm.
Other: Standardization of allergenic extract (Gly. domesticus)
Allergenic extract for cutaneous prick-test

Detailed Description:

The objective of this study is to determine the biologic activity of a Glycyphagus domesticus allergen extract in histamine equivalent prick (HEP) units, in order to be used as in-house reference preparation (IHRP).

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

Subject inclusion criteria:

  1. A documented positive case history with inhalation allergy (rhinitis and/or rhinoconjunctivitis and/or asthma) related to Glycyphagus domesticus.
  2. Positive skin prick test with an available preparation of the same allergen extract (a wheal major diameter of at least 3 mm) and/or a positive test for specific IgE.
  3. Mean of the areas of the wheals provoked by histamine dihydrochloride (10 mg/ml) ≥ 7 mm2.
  4. Age ≥ 18 years and ≤ 50 years
  5. Subject can be male or female
  6. Subject must be capable of providing written informed consent

Subject exclusion criteria:

  1. Subjects should not be excluded due to low or high sensitivity to Glycyphagus domesticus.
  2. Immunotherapy in the past 2 years with an allergen preparation known to interfere with the allergens to be tested.
  3. Use of drugs that may interfere with the skin reactions.
  4. Pregnancy, dermographism, atopic dermatitis (locally at the test site), urticaria.
  5. Any disease which prohibits the use of adrenaline (hyperthyroidism, arterial hypertension, cardiopathy, etc.)
  6. Lack of cooperation which may interfere with the study, or subjects with severe psychiatric, psychological or neurological disorders.
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Please refer to this study by its identifier: NCT00917488

Clinica Dr. Lobatón
Cádiz, Cadiz, Spain, 11008
Sponsors and Collaborators
Laboratorios Leti, S.L.
Principal Investigator: Francisco Moreno, MD, PhD
  More Information

Responsible Party: María José Gómez / Clinical Development Manager, Laboratorios LETI S.L.Unipersonal Identifier: NCT00917488     History of Changes
Other Study ID Numbers: 108-PR-PRI-147
2007-000904-33 ( EudraCT Number )
Study First Received: June 8, 2009
Last Updated: June 17, 2011

Keywords provided by Laboratorios Leti, S.L.:
Allergen extract Standardization

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
Histamine phosphate
Histamine Agonists
Histamine Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs processed this record on June 23, 2017