HIV Reverse Cholesterol Transport Study

Study Overview
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Brief Summary
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Primary Objective: To examine changes in expression of genes [particularly ABCA1 and SREBP2] involved in reverse cholesterol transport (RCT) in monocytes from HIV-infected subjects starting antiretroviral therapy and the different effect of NNRTI and PI based regimens Secondary Objective: To examine changes in monocyte intracellular cholesterol content in HIV-infected subjects starting antiretroviral therapy and the different effect of NNRTI and PI based regimens

Detailed Description
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HIV infection is associated with low HDL-cholesterol, an independent risk-factor for cardiovascular disease (CVD). NNRTI-based HAART increases HDL-c, with nevirapine shown to increase production of its major apolipoprotein ApoA-I. In contrast, initiation of PI-based HAART leads to persistently low HDL-c despite a reduction in HIV RNA and immunologic recovery. HDL-c is formed through reverse cholesterol transport (RCT), the process where cholesterol is transferred from intracellular pools to circulating lipoproteins which are then eliminated by the liver. Accumulation of intracellular cholesterol in cells such as macrophages and their precursor (circulating monocytes) has been implicated in atherogenesis. In vitro data suggests the HIV protein Nef directly interferes with cellular proteins involved in RCT such as ATP-binding cassette transporter A1 (ABCA1) in monocyte-derived macrophages. ABCA1 expression is controlled by peroxisome proliferator-activated receptor gamma (PPARG) and the intracellular cholesterol sensor sterol regulatory element binding protein 2 (SREBP2). In adipose tissue it is known that PI treatment downregulates SREBP and PPARG expression. Preliminary work in the investigators lab has reproduced these findings in monocytes in untreated HIV infection in vivo and demonstrated relationships between gene expression for ABCA1, SREBP2, monocyte intracellular cholesterol and circulating lipoproteins. These early data suggest that defects in RCT determine intracellular cholesterol levels in HIV-infected subjects whereas increased LDL-c is a greater determinant of intracellular cholesterol in HIV negative subjects. This suggests a potentially pivotal role for RCT abnormalities in low HDL-c, increased intracellular cholesterol and atherogenesis in HIV infection. The investigator's aim to examine the impact of initiation of ART with either PI or NNRTI on RCT in circulating monocytes in vivo and how this impact correlates with changes in amount and size of circulating HDL-c.

Official Title
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The Effect of Antiretroviral Therapy and HIV on Reverse Cholesterol Transport in Blood( HIV Reverse Cholesterol Transport Study- HIV RCTS)

Conditions
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HIV, Dyslipidemia

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: > 18 years old HIV-infected Not currently on antiretroviral therapy (>6/12), but about to start Exclusion Criteria: On lipid lowering medication (statin / fibrate / niacin) HCV Ab+

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in ABCA1 mRNA expression in monocytes |  | June 2013 |