Clinical trial NCT00963222: The Study of the Effects of Vitamin A on Immune System in Patients With Atherosclerosis
Official title: The Study of the Effects of Vitamin A Supplementation on Immune System and Th1/Th2 Balance in Patients With Atherosclerosis
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE4
Conditions: Atherosclerosis
Keywords: Atherosclerosis
Coronary Artery Disease
Vitamin A
CD4-Positive T-Lymphocytes
Th1 Cells
Th2 Cells
Lead sponsor: Tehran University of Medical Sciences
Sponsor class: OTHER
First posted: 2009-08-21
Enrollment: 60
Sex: ALL
Minimum age (years): 35
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: The aim of this study is the comparison between the effects of supplementation with 25000 IU preformed vitamin A (retinyl palmitate) or placebo for 3 months on immune system and Th1/Th2 balance in patients with and without atherosclerosis (documented with angiography).

Detailed description: Atherosclerosis, the leading cause of death and disability in the world, is considered an inflammatory disease with a complex etiology. The immune system has a prominent role in the formation, development and destabilization of atherosclerotic plaques. A whole range of identified cytokines have been shown to play a part in atherogenesis, some with proatherogenic properties while others having antiatherogenic properties. With increasing evidence for the significant role of inflammation and the cytokines involved together with the Th1/Th2 imbalance in atherosclerosis and its progression to Coronary artery diseases (CADs), the control of cytokine production may become potential therapeutic targets and modulation of the Th1/Th2 balance may provide a new pharmacological tool to treat this disease. Vitamin A (VA) or VA-like analogs known as retinoids, are potent hormonal modifiers of type 1 or type 2 responses but a definitive description of their mechanism(s) of action is lacking. high level dietary vitamin A enhances Th2 cytokine production and IgA responses, and is likely to decrease Th1 cytokine production. Retinoic acid inhibits IL 12 production in activated macrophages, and RA pretreatment of macrophages reduces IFNγ production and increases IL4 production in antigen primed CD4 T cells. Supplemental treatment with vitamin A or retinoic acid (RA) decreases IFNγ and increases IL5, IL10, and IL4 production. Thus, vitamin A deficiency biases the immune response in a Th1 direction, whereas high level dietary vitamin A may bias the response in a Th2 direction.

Eligibility criteria: Inclusion Criteria:

* The criteria for enrollment of the patients and control subjects is consecutive patients of both sexes referred to the Division of Cardiology of the one of the Hospitals of Tehran University of Medical Sciences for coronary angiography for investigation of chest pain and/or suspected CAD.

Exclusion Criteria:

* Patients who have diseases which affect on Th1/Th2 balance such as asthma, active viral infections, and autoimmune diseases, OR
* Patients who have allergy to vitamin A compounds, OR
* Patients who have used vitamin supplements in last 3 months.

Primary outcomes:
measure: Serum levels of IL4, IL10, IFN γ, IL2, IL12
timeFrame: first day and after 3 month
measure: PBMC supernatant levels of IL4, IL10, IFN γ, IL2, IL12
timeFrame: first day and after 3 month
Secondary outcomes:
measure: serum Total cholesterol
timeFrame: first day and after 3 month
measure: serum HDL cholesterol
timeFrame: first day and after 3 month
measure: serum triglycerides level
timeFrame: first day and after 3 month
measure: serum Apo A, Apo B and CRP levels
timeFrame: first day and after 3 month
measure: serum oxLDL
timeFrame: first day and after 3 month
measure: RBP/ TTR ratio
timeFrame: first day and after 3 month
measure: lymphocyte proliferation assay (MTT)
timeFrame: first day and after 3 month
Other outcomes:
Locations:
city: Tehran
country: Iran, Islamic Republic of
facility: Tehran University of Medical Sciences, School of Public Health
Study officials:
affiliation: Tehran University of Medical Sciences
name: Ali Akbar saboor Yaraghi, PhD
role: STUDY_CHAIR
affiliation: Tehran University of Medical Siences
name: Maryam Mahmoudi, MD, PhD student
role: PRINCIPAL_INVESTIGATOR
affiliation: Tehran University of Medical Sciences
name: Fereidon Siassi, PhD
role: STUDY_CHAIR
References: