Comparing Allergenic Effects of 3 German Cockroach Extracts in Adults

Asthma Clinical Trial

Official title: German Cockroach Allergen Standardization Evaluation (CASE)

Status Terminated

Clinical Trial Summary

The purpose of this study is to test and compare the allergenic effects of three commercially available German cockroach allergen extracts in adults.

Study hypothesis: The biological potency of three commercially available German cockroach allergy extracts can be compared using the ID50EAL method to standardize German cockroach allergens.

Clinical Trial Description

Cockroach allergens appear to be a major cause of inner city asthma. Because of the suspected relationship between domestic cockroach species and allergy and asthma symptoms, the Food and Drug Administration (FDA) wants to standardize cockroach allergen vaccines for use in the U.S. Allergen standardization comprises two important components: the selection of a reference preparation of allergenic extract and the selection of procedures to compare manufactured products to the reference allergen extract.

Adults in this study will be exposed to different doses of each of 3 German cockroach allergen extracts via intradermal skin testing. Participants in this study will be adults who have a history of allergic disease or asthma and are sensitive to the German cockroach allergens being tested.

Participants will have 2 visits during this study: a screening session and a testing session. At screening, participants will be asked to complete a screening questionnaire and will undergo a targeted physical exam, vital signs measurement, and peak expiratory flow (PEF) testing. Premenopausal women will also have urine collected for pregnancy testing. At the screening session, a 15-minute prick/puncture test will be administered on the skin of the forearm with the proposed standard allergen extract, histamine (positive control), and diluent (negative control). Skin erythema (swelling) response to the injections will be recorded.

Some participants may continue into the testing session on the same day as the screening session; others will participate in the testing session at a second study visit within 4 weeks after study screening. At the start of the testing session, participants will be asked to complete a questionnaire about demographics, history of airway disease and previous skin testing, and current medication use. For participants whose testing session occurs on a different day than the screening session, vital signs measurement and PEF readings will occur and premenopausal women will have urine collected. Blood collection will occur prior to the skin test. Intradermal skin testing will consist of injections on the participant's back with multiple doses of 3 different extracts of German cockroach allergen. Each of the 3 extracts will require 4 to 7 injections, depending on the response to each dose. Erythema skin response to the dilutions will be recorded. Participants will be observed for at least 1 hour after the intradermal skin testing as a safety precaution. After the observation period, participants will undergo additional PEF testing and will be assessed for adverse reactions to the skin testing procedure. Participants may be given antihistamines to relieve itching. ;

Study Design

Observational Model: Cohort, Time Perspective: Prospective

Related Conditions & MeSH terms

• Allergy
• Asthma

• NCT number: NCT00132847
• Study type: Observational
• Source: National Institute of Allergy and Infectious Diseases (NIAID)
• Status: Terminated
• Phase: N/A
• Start date: April 2004
• Completion date: October 2004