Determination of the Sensitivity and Specificity of Prick Test Betula Verrucosa
Condition: Immune System Diseases
MeSH terms: Immune System Diseases
Intervention: 10 HEP/mL Betula verrucosa allergen extract; 25 HEP/mL Betula verrucosa allergen extract; 50 HEP/mL Betula verrucosa allergen extract; 100 HEP/mL Betula verrucosa allergen extract
Intervention description: The investigational product contained 10 HEP/mL Betula verrucosa allergen extract and was tested by administration onto skin. The test was carried out on the forearm following prick test technique.; The investigational product contained 25 HEP/mL Betula verrucosa allergen extract and was tested by administration onto skin. The test was carried out on the forearm following prick test technique.; The investigational product contained 50 HEP/mL Betula verrucosa allergen extract and was tested by administration onto skin. The test was carried out on the forearm following prick test technique.; The investigational product contained 100 HEP/mL Betula verrucosa allergen extract and was tested by administration onto skin. The test was carried out on the forearm following prick test technique.
Phase: Phase 2
Study type: Interventional
Primary purpose: Diagnostic
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 201.0
Sex: All
Minimum age: 5 Years
Maximum age: 70 Years
Healthy volunteers: No
Keywords: Immune System Diseases; Prick Test; Betula verrucosa

Summary:

      The main objective is to evaluate the concentration of allergen extract of Betula verrucosa
      that elicit a papule equivalent to that produced by a solution of histamine dihydrochloride
      10 mg / ml in size.
    

Eligibility criteria:

        General inclusion criteria for both groups:

          -  Positive skin prick test with the positive control (Histamine HCl at 10 mg/mL). The
             length of the largest diameter of the wheal induced by this control should be ≥ 3 mm.

          -  Negative skin prick test with the negative control. The length of the largest diameter
             of the wheal induced by this control should be < 3 mm.

          -  All ages and both genders.

        For the group of patients CH+ (true positive to Betula verrucosa): All these patients had a
        previous diagnosis of allergy to the birch pollen:

          -  A positive case history with inhalant allergy related to exposure to birch pollen.

          -  A positive skin prick test (mean wheal diameter ≥ 3 mm) when tested with a
             biologically standardized extract prepared from birch pollen. This preparation, from
             another manufacturer, was the one used in the routine in the Hospital.

          -  Positive test for specific IgE (CAP value > 0.35 IU/mL). For the group of patients CH-
             (true negative to Betula verrucosa): All these patients had a previous diagnosis of
             allergy to agents unrelated to birch pollen.

          -  A negative case history with inhalant allergy related to exposure to birch pollen or
             to pollen with known cross-reactivity with the birch pollen. These patients could be
             allergic to other pollen or other allergens, such mites.

          -  A negative prick test (largest diameter of the wheal ≥ 3 mm) when tested with a
             standardized extract prepared from the allergen source in question.

          -  A negative test for specific IgE (CAP value < 0.35 IU/mL) to birch pollen or to pollen
             with known cross-reactivity with birch pollen: Corylus avellana, Quercus verrucosa,
             Fagus sylvatica, Castanea satavia, Carpinus betelus and Alnus glutinosa.

        Exclusion criteria for both groups:

          -  Patients that were using drugs that may interfere with the skin prick tests.

          -  Patients using the following drugs 24 hours before the test: theophylline, systemic
             corticosteroids.

          -  Patients in which the largest diameter of the wheal induced by the positive control
             was < 3 mm.

          -  Patients in which the largest diameter of the wheal induced by the negative control
             was ≥ 3 mm.

          -  Pregnancy, dermographism, atopic dermatitis (locally at the test site), urticaria.

          -  Patients who suffer disease in which the use of adrenaline is not allowed.

          -  Patients with any severe psychiatric disease.

        For the patients CH+:

        • Patients that received or are treated with immunotherapy with an allergenic extract of
        birch pollen and/or with allergen extracts with known cross-reactivity to birch pollen
        (Corylus avellana, Quercus verrucosa, Fagus sylvatica, Castanea satavia, Carpinus betelus
        and Alnus glutinosa).

        For the patients CH-:

          -  Patients sensitized to pollen with demonstrated cross-reactivity with the pollen of
             Betula verrucosa. These pollen included Corylus avellana, Quercus verrucosa, Fagus
             sylvatica, Castanea satavia, Carpinus betelus and Alnus glutinosa.