This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Genetic Studies in Difficult to Treat Asthma: TENOR

This study has been completed.
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI) Identifier:
First received: September 16, 2004
Last updated: July 11, 2016
Last verified: July 2008
To investigate genetic factors that affect asthma severity.

Asthma Lung Diseases

Study Type: Observational

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: September 2004
Study Completion Date: June 2008
Primary Completion Date: June 2008 (Final data collection date for primary outcome measure)
Detailed Description:


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.


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.


Ages Eligible for Study:   6 Years to 100 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
No eligibility criteria
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00091767

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
OverallOfficial: Eugene Bleecker Wake Forest University Health Sciences
  More Information Identifier: NCT00091767     History of Changes
Other Study ID Numbers: 1270
R01HL076285-03 ( U.S. NIH Grant/Contract )
Study First Received: September 16, 2004
Last Updated: July 11, 2016

Additional relevant MeSH terms:
Lung Diseases
Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases processed this record on August 23, 2017