The COX-2 Gene and the Immune System

June 5, 2026 updated by: National Institute of Environmental Health Sciences (NIEHS)

The Role of Functionally Relevant Cyclooxygenase-2 (COX-2) Gene Single Nucleotide Polymorphisms - 765G>C and 8473T>C in Lymphocyte Differentiation

Background:

- The immune system contains several different types of cells in the blood and other parts of the body. The body can fight infections well with the right balance of these cell types. The wrong balance of cell types may cause diseases, such as allergies or asthma. The COX-2 gene may help decide the balance of cell types that the body makes as part of the immune system. It may also play a role in certain immune system diseases. Researchers want to see how COX-2 affects the cells in the immune system.

Objectives:

- To study how the COX-2 gene works in the body s immune system.

Eligibility:

- Individuals 18 years of age and above who are part of the Environmental Polymorphisms Registry.

Design:

  • Participants will have one study visit at the National Institutes of Health. They will collect a urine sample at home on the morning of the study visit.
  • Participants will have a physical exam and medical history. They will provide a blood sample. They will also give researchers the urine sample they collected that morning.
  • No treatment will be provided as part of this study.

Study Overview

Status

Completed

Conditions

Detailed Description

This is a cross-sectional, controlled study designed to investigate the association of single nucleotide polymorphisms (SNPs) in the cyclooxygenase-2 (COX2) gene, also called prostaglandin endoperoxidase synthase 2 (PTGS2), on T-cell differentiation and function. Specifically, the impact of the promoter-region SNP 765G>C (rs20417) and the 3 untranslated region (UTR) SNP 8473T>C (rs5275) on T helper cell (Th) 2, Th9, and Th17 differentiation and function will be examined. Non-Hispanic, White or Black/African American, non-pregnant adults, aged 18-65 years, who are wild type (WT), with respect to both the 765G>C and 8473T>C SNPs, WT with respect to 765G>C and homozygous for 8473T>C, and homozygous for both 765G>C and 8473T>C will be recruited into a total of three genotype groups. Potential participants will be identified from the Environmental Polymorphisms Registry, contacted by recruitment letter and pre-screened for eligibility. Pre-screened individuals will provide verbal consent to withhold certadata analysis, a urine collection cup, and pre-visit instructions. Participants will attend a single study visit that will take place at the National Institute of Environmental Health Sciences (NIEHS) Clinical Research Unit (CRU). During this visit, written informed consent will be obtained, and there will be a final screening and eligibility determination, medical history review, vital signs, physical examination and blood and urine samples will be collected. From peripheral blood, lymphocyte subsets, prostaglandin levels, and cytokine levels will be determined; stable prostaglandin metabolites, creatinine, total protein and albumin will be measured in urine. Lymphocytes will be isolated from peripheral blood for ex vivo analyses. Demographic characteristics (i.e., age) will be compared between the groups, and when possible, recruitment will be targeted to achieve an approximate match of race and gender across the groups. The primary objective of the study is to determine whether the 765G>C or 8473T>C SNPs exhibit altered Th2, Th9 and Th17 cell differentiation by examining lymphocyte subsets in vivo. The study will also examine the impact of these two SNPs on circulating Th2/Th9/Th17 cytokine levels and prostaglandins in vivo, on differentiation of naive CD4+T-cells to Th cell subsets in vitro, and on lymphocyte production of cytokines and prostaglandins in vitro.

Study Type

Observational

Enrollment (Actual)

117

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • North Carolina
      • Research Triangle Park, North Carolina, United States
        • NIEHS Clinical Research Unit (CRU)

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

18 years to 150 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

individuals who are homozygous for either the major or minor variant of both SNPs@@@

Description

  • INCLUSION CRITERIA:
  • Participant of the Environmental Polymorphisms Registry and current contact information available

  • Genotype information available for relevant 765G>C and 8473T>C COX2 polymorphisms, which indicates:

    • Individuals who are WT with respect to both 765G>C and 8473T>C (N=31)
    • Individuals who are WT with respect to 765G>C and homozygous for 8473T>C (N=31)
    • Individuals who are homozygous for both 765G>C and 8473T>C (N=31)
  • Age 18- 65 years
  • Race self-identified as White or Black and Non-Hispanic ethnicity
  • Willing and able to provide informed consent
  • Able to comply with all protocol procedures

EXCLUSION CRITERIA:

  • History of infection within the preceding 1 week or an oral temperature >38 degrees C
  • Current daily or chronic use of corticosteroids (systemic, inhaled and topical).
  • Any current conditions known to impact peripheral white blood cell count (e.g., leukemia, lymphopenia, AIDS, other immunodeficiency disorders)
  • Current daily or chronic use of systemic immunosuppressants.
  • Current pregnancy or lactation

  • Unwilling or unable to:

    • Fast (including alcohol and caffeine-containing products) and discontinue tobacco use for 12 hours prior to the study visit
    • Withhold all prescribed and over-the-counter medications and supplements the morning of the study visit, until after the visit is completed

    • Refrain from taking the following medications and supplements for 7 days prior to the study visit:

      • NSAIDs
      • Corticosteroids (nasal, inhaled, topical or systemic)
      • Fish oil and niacin supplements
  • For blood draws that exceed 200ml, a hematocrit of <34% for women or <36% for men, or >56% for either gender.
  • For blood draws exceeding 200ml, blood or plasma donation in the last 8 weeks

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?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Cross-Sectional

Cohorts and Interventions

Group / Cohort
SNP
individuals who are homozygous for either the major or minor variant of both SNPs

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
To determine whether 765>C is associated with altered Th2, Th9, and Th17 differentiation in vivo
Time Frame: Ongoing
To determine whether 765>C is associated with altered Th2, Th9, and Th17 differentiation in vivo
Ongoing
To determine whether 8473T>C is associated with altered Th2, Th9, and Th17 differentiation in vivo
Time Frame: Ongoing
To determine whether 8473T>C is associated with altered Th2, Th9, and Th17 differentiation in vivo
Ongoing

Collaborators and Investigators

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

Sponsor

National Institute of Environmental Health Sciences (NIEHS)

Investigators

  • Principal Investigator: Darryl C Zeldin, M.D., National Institute of Environmental Health Sciences (NIEHS)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

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 (Actual)

May 2, 2013

Study Registration Dates

First Submitted

August 30, 2012

First Submitted That Met QC Criteria

August 30, 2012

First Posted (Estimated)

September 3, 2012

Study Record Updates

Last Update Posted (Actual)

June 8, 2026

Last Update Submitted That Met QC Criteria

June 5, 2026

Last Verified

September 18, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 120190
  • 12-E-0190

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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