Biological Standardization of D. Glomerata, L. Perenne, S. Cereale and O. Europaea Pollen Extracts

Summary

Allergen extracts are complex mixtures of proteins and contain varying amounts of allergenic and non-allergenic components. Many factors such as the biovariability, differences in extraction process and subsequent handling of allergens can affect the final composition, potency, and stability of allergen preparations. Genetic diversity of affected people adds another level of complexity. In order to control variability and to achieve consistency and reproducibility for optimal safety and sensitivity/specificity, it is essential to standardize the amount of allergen used in prick tests. Therefore, the system for biological standardization mainly used in Europe still is the biological calibration of in-House Reference Preparations (IHRP). The method has been adopted by the Nordic Council on Medicines as the Nordic Biological Unit, Histamine Equivalent Potency (HEP) or Skin Prick Test (SPT) value. The aim of this procedure is to estimate the biological activity of allergen extracts. The activity of an allergen extract is defined as 1 SPT per ml, when the extract provokes a specific skin reaction with a wheal of the same size as a wheal provoked by reference histamine at a concentration of 10 mg/ml, when both solutions are administrated using the same technique (prick testing) on at least 20 individuals who are sensitized to the allergen concerned.

The present study aims to standardize the allergen extracts of Dactylis glomerata, Lolium perenne, Secale cereale y Olea europaea by using this method.

Conditions

• Sensitization to Allergens

Interventions

BIOLOGICAL

Skin Prick Test

Skin prick test of 4 concentrations of each allergenic source, 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. Assessment of the wheal size after 15 minutes.

BIOLOGICAL

Skin Prick Test - Atopic Subjects

Skin prick test of 4 concentrations of each allergenic source,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. Assessment of the wheal size after 15 minutes.

BIOLOGICAL

Skin Prick Test - No Atopic Subjects

Skin prick test of 4 concentrations of each allergenic source, 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 subjects in duplicate on the volar surface of the forearm. Assessment of the wheal size after 15 minutes.

Sponsors & Collaborators

• Roxall Medicina España S.A

  lead INDUSTRY

Principal Investigators

• Arantza Vega, MD · Hospital Universitario de Guadalajara

• Pilar Alba, MD · Hospital de Manises

• José Manuel Zubeldia, MD · Hospital Universitario Gregorio Marañón

• María Ángeles Gonzalo Garijo, MD · Hospital Universitario Infanta Cristina

• Carlos Colás, MD · Hospital Clínico Universitario Lozano Blesa

• Blanca Saenz de San Pedro · Complejo Hospitalario de Jaén

• Lourdes Fernández, MD · Hospital Universitario Reina Sofía

Study Design

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2012-02-29

Primary Completion

2012-11-30

Completion

2012-11-30

Countries

• Spain

Study Locations