Genetic Studies in Difficult to Treat Asthma: TENOR

To investigate genetic factors that affect asthma severity.

Study Overview

Status

Completed

Conditions

Detailed Description

BACKGROUND:

The TENOR (The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens) study is an ongoing three-year multi-center observational cohort study of 4756 severe or difficult-to-treat patients with asthma aged 6 or older. Of this group of asthmatics, 44.6% meet the National Heart, Lung, and Blood Institute National Asthma Education and Prevention Program guidelines for severe persistent asthma, 27.5% for moderate persistent asthma, and 27.8% for mild persistent asthma. All subjects were evaluated initially with comprehensive questionnaires and laboratory testing, and are then seen every 6 months during the remaining 3 years of the study. Phenotypic information collected includes information on asthma exacerbations, medication use, urgent care visits, quality of life, pulmonary function tests (spirometry with reversibility), total serum IgE levels, and history of allergies. If accessed now, before the termination of the TENOR study, this population represents one of the largest populations of phenotypically characterized difficult-to-treat and severe asthmatics potentially available for genomic and pharmacogenetic studies. TENOR will finish at the end of 2004, thus there is a very short time window in which to obtain DNA samples for genetic studies before the termination of the study. Isolation and storage of DNA from this well characterized, longitudinal population will serve as a resource not only for the studies in this grant but also for future genomics and pharmacogenetic studies in asthma.

DESIGN NARRATIVE:

The study investigates genetic factors that affect asthma severity in the TENOR subjects. The study tests the hypothesis that factors which produce difficult-to-treat and severe asthma are produced by altered inflammatory responses that are related, at least in part, to sequence variants (polymorphisms) in genes that regulate inflammation, allergic responsiveness, and/or affect structural components in the airways. The study also tests the hypothesis that some patients develop more severe asthma because of genetic differences that modulate their responses to pharmacologic agents. To test these hypotheses, the following specific aims will be carried out: 1) Obtain DNA samples from at least 4,000 asthmatics currently enrolled in the ongoing TENOR study; 2) Determine whether sequence variants (polymorphisms) in genes that regulate inflammation, cellular responses, and/or tissue injury and repair are more frequently associated with asthma severity using the baseline data; 3) Determine the importance of genetic polymorphisms in genes that may be important in IgE regulation in this population of difficult-to-treat patients with asthma; 4) Evaluate pharmacogenetic relationships between polymorphisms in the a2 adrenergic receptor (a2AR) in those subjects on long-acting beta-2-agonists to determine the effect on asthma severity; 5) Evaluate pharmacologic mechanisms by investigating whether polymorphisms in genes that regulate responses to asthma therapy are more frequent in severe disease.

Study Type

Observational

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

6 years to 100 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

No eligibility criteria

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Eugene Bleecker, Wake Forest University Health Sciences

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2004

Primary Completion (Actual)

June 1, 2008

Study Completion (Actual)

June 1, 2008

Study Registration Dates

First Submitted

September 16, 2004

First Submitted That Met QC Criteria

September 17, 2004

First Posted (Estimate)

September 20, 2004

Study Record Updates

Last Update Posted (Estimate)

July 12, 2016

Last Update Submitted That Met QC Criteria

July 11, 2016

Last Verified

July 1, 2008

More Information

Terms related to this study

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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