The Interplay of the Osteoprotegerin/RANKL Axis and Dysfunctional HDL in HIV-Infected Adults AIDS Clinical Trials Group Study NWCS 332/A5078

Kelesidis T, Kendall MA, Yang OO, Currier JS for the NWCS 332/A5078 Team

Abstract THAB0201, IAS 2012, July 26th, 2012

Oxidized Lipids as a link between oxidative stress and the RANKL-OPG pathway

Oxidative stress

Abstract THAB0201, IAS 2012, July 26th, 2012Graham et al Clin Immunol 2009; Graham et al J Bone Miner Res 2010; Zhang et al Diabetes Metab Res Rev 2010; 26(6):455-463).

RANKL

OPG

T cells

CD4 T cells CD8 T cells

TRAILOPG

RANKL

T cell activationB cells

HIV infection

INFLAMMATION: Proinflammatory cytokines and chemokines

ARTHIV infection

HIV infection as a model for systemic oxidative stress: Possible cross-talk between HIV infection and the RANKL-OPG axis

• Antivir Ther 2011; 16:1063; AIDS 2005; 19:1240; AIDS 2007; 21:1129; J Med Virol 2007; 79:1446-1454Abstract THAB0201, IAS 2012, July 26th, 2012

Dysfunctional HDL in the intersection of HIV infection and the RANKL-OPG axis

• We have previously shown that HIV-infected subjects with suppressed viremia have dysfunctional HDL and that oxidized HDL is dysfunctional HDL Kelesidis et al JLR 2011, Lipids Health Dis 2011, Lipids Health Dis 2012

• Limited data exist regarding the relationship between dysfunctional HDL (ox-HDL) and the osteoprotegerin (OPG)/receptor activator of the NF-kB ligand (RANKL) in HIV infection.

Abstract THAB0201, IAS 2012, July 26th, 2012

Hypothesis/Study Aims

We hypothesized that increased serum levels of RANKL/OPG are independently associated with lipid levels and functional (redox) properties of HDL in HIV infected subjects

RANKL

OPG

RANKL/OPG

Lipid levels (TC, HDL, LDL)

HDL redox activity (HDLox)

Abstract THAB0201, IAS 2012, July 26th, 2012

Kelesidis et al J Lipid Res 2011 52(12):2341-51Abstract THAB0201, IAS 2012, July 26th, 2012

Methods: Oxidation rate of a fluorescent probe (DOR) as an vitro biochemical measure of HDL redox activity

HIV-uninfected subjects (n=36)

Non-PI n=26 (47%)

Design: We used a subgroup of stored serum samples (n=91) from a previously completed prospective matched 3-year study (ACTG 5078) (Currier J et al AIDS 2007, 21:1137-1145)

HIV-infected (HIV RNA < 500 copies/mL (n=55)

PI n=29 (53%)

Abstract THAB0201, IAS 2012, July 26th, 2012

Matched by: • Cardiovascular

risk factors • Age within 5 years• Race• Sex• Blood pressure

status• Smoking status• Menopausal

status

Design

Results (1) : Metabolic Abnormalities HIV vs Control

Characteristic  Total

(N=91)HIV

(N=55)Not HIV (N=36)

P value

Gender Male 84 (92%) 52 (95%) 32 (89%) 0.428Age (years) Median

(IQR)41 (36-45) 41 (37-45) 40 (36-45) 0.589

Race/Ethnicity White Non-Hispanic

69 (76%) 42 (76%) 27 (75%) 0.547

  Hispanic 17 (19%) 9 (16%) 8 (22%)  Metabolic Syndrome

Present 11 (12%) 10 (18%) 1 (3%) 0.045

Triglycerides (mg/dl)

≥ 150 39 (43%) 29 (53%) 10 (28%) 0.030

Use of Lipid Lowering

Drugs

Any 12 (13%) 12 (22%) 0 (0%) 0.003

Abstract THAB0201, IAS 2012, July 26th, 2012

Results (2): HIV infected subjects had significantly lower RANKL and RANK/OPG compared to uninfected subjects

Abstract THAB0201, IAS 2012, July 26th, 2012

Results (3) Baseline levels of the rate of oxidation of the fluorescent probe did not significantly differ between HIV infected and uninfected subjects

Abstract THAB0201, IAS 2012, July 26th, 2012

Results (4) Serum levels of RANKL-OPG axis are independently associated with baseline levels of lipids and Dysfunctional HDL in HIV-

1 infection

For each 10 units > average baseline RANKL/OPG

DOR by 0.81 (0.16, 1.47) x 104 FU/min

In multivariate analyses within the HIV-infected (but NOT within uninfected)subjects

HDL redox activity

↑ HDL ≥35 mg/dl ΔRANKL

ΔOPG↑ Τotal cholesterol ≥ 200 mg/dl

Abstract THAB0201, IAS 2012, July 26th, 2012

Results (5) The RANKL/OPG NFkB pathway is associated with changes in levels of lipids in HIV-infected subjects

Abstract THAB0201, IAS 2012, July 26th, 2012

HIV Non HIV

HD

L re

dox

activ

ity (F

U/m

in)

RANKL/OPG ratio RANKL (pg/ml)

HIV

HD

L re

dox

activ

ity (F

U/m

in)

RANKL (pg/ml)

RANKL/OPG ratio

Non HIV

Results (6) The RANKL/OPG NFkB pathway is associated with HDL redox activity in HIV-infected subjects

Abstract THAB0201, IAS 2012, July 26th, 2012

Summary

• HIV-infected subjects on ART had significantly lower levels of total serum RANKL and RANKL/OPG ratio compared to HIV-uninfected subjects at both baseline and after 2-3 years of follow-up.

• Higher baseline levels of HDL and total cholesterol were significantly associated with higher ΔRANKL and ΔOPG in HIV infected but not in uninfected subjects.

• Functional properties of HDL were significantly associated with the serum RANKL/OPG ratio in HIV infected but not in uninfected subjects.

Abstract THAB0201, IAS 2012, July 26th, 2012

Conclusions

• RANKL/OPG axis may be aberrantly regulated in HIV-infected compared to -uninfected adults and is independently associated with baseline levels of cholesterol and changes in functional properties of HDL in HIV-infected subjects.

• The interplay between T lymphocytes, lipids may explain our findings.

• These in vivo data are consistent with previous in vitro results that have shown that oxidized HDL may affect the NF-kB pathway (Clin Immunol 2009; 133(2):265-275; J Bone Miner Res 2010; 25(11):2460-2469; Diabetes Metab Res Rev 2010; 26(6):455-463).

• Further studies need to establish the relationship between lipids, T cells, RANKL-OPG axis and HDL function in HIV infection.

Abstract THAB0201, IAS 2012, July 26th, 2012

AcknowledgementsStatistician: Michelle Kendall, M.S., HSPHInvestigators: Judith Currier, M.D., M.Sc., UCLA Otto Yang, MD, UCLA

Howard Hodis, MD USC Special Thanks to the Study Participants