NCT02474836

Determination of Biological Activity of Three Allergen Extracts

Biological Standardization of Artemisia Vulgaris and/or Platanus Acerifolia Pollen Extract and Dermatophagoides Farinae Mite Extract in Patients Sensitized to Them

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 176 (actual)
• Sponsor: Roxall Medicina España S.A · Industry
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

Allergen extracts are complex mixtures of proteins and contain varying amounts of allergenic and non-allergenic components. Many factors such as the variability, 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 Artemisia vulgaris, Platanus acerifolia, Dermatophagoides farinae by using this method.

Detailed description

The present study aims to standardize the allergen extracts of Artemisa vulgaris, Platanus acerifolia and Dermatophagoides farinae by using this method. Standardized extracts will then be used for diagnostics and treatment of allergies as mentioned above.

Conditions

• Hypersensitivity

Interventions

Type	Name	Description
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 - Non 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.
BIOLOGICAL	Skin Prick Test - Allergic 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.

Timeline

• Start date: 2012-11-01
• Primary completion: 2013-09-01
• Completion: 2013-09-01
• First posted: 2015-06-18
• Last updated: 2017-05-01

Locations

9 sites across 1 country: Spain