Clinical trial NCT00090740: Genetic Risk Factors for Severe Asthma
Official title: Genetic Risk Factors for Severe Asthma
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Asthma
Lead sponsor: National Institute of Allergy and Infectious Diseases (NIAID)
Sponsor class: NIH
First posted: 2004-09-06
Enrollment: 600
Sex: ALL
Minimum age (years): 18
Maximum age (years): 44
Standard ages: ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: 400 asthmatics and 200 non-asthmatic controls will be recruited. The 200 non-asthmatics will be matched for age, gender and ethnicity with the asthmatics in the more severe half of the severity distribution. The participants will be from minority populations (at least 30% African-American and at least 30% Hispanic) and generally of lower socioeconomic status.

Brief summary: The purpose of this study is to determine whether a specific genetic factor influences the severity of asthma symptoms.

Detailed description: Asthma is one of the most common chronic diseases in the United States. It is well known that asthma susceptibility is inherited; however, it is unknown if asthma severity is heritable. Studies suggest that levels of interleukin-16 (IL-16) may influence asthma severity. This study will examine the role of differences in the control region of the IL-16 gene in a racially diverse group of asthmatics and nonasthmatics and will determine if the IL-16 gene control region is related to asthma severity.

Participants in this study will undergo lung function and blood tests; they will also complete a questionnaire about their respiratory health. Asthmatic participants will complete a severity-of-asthma questionnaire.

Eligibility criteria: Inclusion Criteria for Asthmatic Participants:

* Diagnosis of asthma

Inclusion Criteria for Non-asthmatic Participants:

* No diagnosis of asthma

Primary outcomes:
measure: Examination of the relationship between the IL-16 promoter genotype and the presence of the asthma phenotype
timeFrame: Throughout study
measure: Examination of the relationship between the IL-16 promoter genotype and asthma severity
timeFrame: Throughout study
measure: Examination of the serum IL-16 concentration and the serum IL-16:IL-9, IL-16:IL-13, and IL-16: TNF-alpha ratios as possible intermediate phenotypes lining the IL-16 promoter genotype to asthma severity
timeFrame: Throughout study
Secondary outcomes:
measure: Storage of DNA from all 600 participants for future study into the determinants of asthma severity
timeFrame: Throughout study
Other outcomes:
Locations:
city: Boston
country: United States
facility: Boston University School of Medicine
state: Massachusetts
Study officials:
name: George O'Connor, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Sandford AJ, Chagani T, Zhu S, Weir TD, Bai TR, Spinelli JJ, Fitzgerald JM, Behbehani NA, Tan WC, Pare PD. Polymorphisms in the IL4, IL4RA, and FCERIB genes and asthma severity. J Allergy Clin Immunol. 2000 Jul;106(1 Pt 1):135-40. doi: 10.1067/mai.2000.107926.
citation: Xu J, Meyers DA, Ober C, Blumenthal MN, Mellen B, Barnes KC, King RA, Lester LA, Howard TD, Solway J, Langefeld CD, Beaty TH, Rich SS, Bleecker ER, Cox NJ; Collaborative Study on the Genetics of Asthma. Genomewide screen and identification of gene-gene interactions for asthma-susceptibility loci in three U.S. populations: collaborative study on the genetics of asthma. Am J Hum Genet. 2001 Jun;68(6):1437-46. doi: 10.1086/320589. Epub 2001 May 10.
citation: Lee SY, Lee YH, Shin C, Shim JJ, Kang KH, Yoo SH, In KH. Association of asthma severity and bronchial hyperresponsiveness with a polymorphism in the cytotoxic T-lymphocyte antigen-4 gene. Chest. 2002 Jul;122(1):171-6. doi: 10.1378/chest.122.1.171.
citation: Szalai C, Kozma GT, Nagy A, Bojszko A, Krikovszky D, Szabo T, Falus A. Polymorphism in the gene regulatory region of MCP-1 is associated with asthma susceptibility and severity. J Allergy Clin Immunol. 2001 Sep;108(3):375-81. doi: 10.1067/mai.2001.117930.