Metabolic Abnormalities and Mitochondrial Function in Children with Perinatally-Acquired HIV Infection in the

Pediatric HIV/AIDS Cohort Study (PHACS)

Mariana Gerschenson, Ph.D.Tracie L. Miller MD, Jiajia Wang MS, Denise L. Jacobson PhD, MPH, Jody K. Takemoto PhD, Tanvi Sharma MD, Mitchell Geffner MD, Daniel E. Libutti BS,

Susanne Siminski MS, MBA, Gabriel Somarriba DPT, and Patricia Graham MSfor the Pediatric HIV/AIDS Cohort Study

July 23, 2012XIX International AIDS Conference

Background

• Insulin resistance is common among perinatally HIV-infected children (HIV+)

• Mitochondrial dysfunction, induced by antiretroviral therapy (ARV) or chronic viral infection, is a possible mechanism for metabolic dysfunction

Mitochondrial Function

• Make ATP– Oxidative phosphorylation ATP– Citric acid cycle: NADH and FADH ATP – Fat metabolism: beta oxidation ATP

• Responsible for 90% of the oxygen radicals/oxygen stress

• Mitochondrial DNA (mtDNA)– 16 kb, 2-10 copies/mitochondrion in matrix– Replication: mitochondrial genes

• The mtDNA polymerase-γ is the principal polymerase required for mtDNA replication

– Transcription: mitochondrial proteins• Mitochondrial RNA (mtRNA) polymerase and

transcription factors

• Apoptosis• Lactic acidosis

Adipocyte TEM courtesy of Courtney Kim and Mariana Gerschenson

Mitochondria Inner Structure

HIV

InnerMembrane

OuterMembrane

Cristae

Matrix

Adipocyte TEM

Hypothesis: Potential Consequences of Mitochondrial Dysfunction

Cardiovascular DiseaseLipodystrophy

• Neuropathies• Hepatic Steatosis• Myopathy• Pancreatitis• Lactic Acidosis

Metabolic Disease (LD, IR, TGs)

ARTCytokines

Day L, et al. Mitochondrion. 2004;4:95–109. AACTG Metabolic Guides: http://aactg.s-3.com/metabolic/lactic.pdf. McComsey GA, Morrow JD. J Acquir Immune Defic Syndr. 2003;34:45-9. Dagan T, Sable C, Bray J, Gerschenson M. Mitochondrion. 2002;1:397-412. Gerschenson, M. and Brinkman, K. Mitochondrion. 2004;4(5-6):763-777.

HIV

HIV

• DNA polymerase-g• Transcription• Uncoupling• Transport• Oxidative Stress• Apoptosis• Phosphorylation• Proteolytic Processing• Glycosylation

Hypothetical Model for HIV Pediatric Metabolic Disease

BMI/ Body Measurements

LDL/HDL/TG/HOMA-IR (Glucose)

OXPHOSKrebs

β-oxidation

LactateHIV/ART

Objectives

• To compare mitochondrial function [oxidative phosphorylation (OXPHOS) enzyme activities and lactate levels] of 191 HIV+ and 117 HIV-exposed, uninfected (HEU) children and among HIV+, determine associations with homeostatic model assessment of insulin resistance (IR) (HOMA-IR) and hyperlipidemia

• In HIV+ children, to determine if mitochondrial function (oxidative phosphorylation [OXPHOS] enzyme activities and lactate and pyruvate levels) are associated with metabolic abnormalities (IR and hyperlipidemia)

Mitochondrial Determinant Component of PHACS

• The Adolescent Master Protocol (AMP), a part of the Pediatric HIV/AIDS Cohort Study (PHACS), is a prospective cohort study conducted at 12 US sites designed to define the impact of HIV infection and ARV on pre-adolescents and adolescents with perinatal HIV infection.

• The Mitochondrial Determinants Component (MDC) is a separately funded study (R01 NR12885) that has co-enrolled AMP participants since May 2011.

• The objective of MDC is to determine the influence of mitochondrial abnormalities on metabolic outcomes in HIV+ children who were previously enrolled in AMP from 7 years of age until their 16th birthday. HIV-exposed, uninfected children (HEU) are also enrolled to serve as controls.

Demographics of Cohort by HIV Status

Characteristic HIV+ (191) HEU (117) Total (308) P-valueAge, median (yr) 15.8 12.7 14.5 <0.001*Male (%) 104 (54) 60 (51) 164 (53) 0.64**Race, NHB (%) 133 (70) 66 (56) 199 (65) 0.05**Tanner stage 1 (%)Tanner stage 2-3 (%)Tanner stage 5 (%)

9 (5)68 (36)83 (43)

14 (12)72 (63)19 (16)

23 (7)140 (45)102 (33)

<0.001**

BMI Z-score, median 0.46 0.91 0.59 0.005*

*Wilcoxon Test** Fisher’s Exact Test

Clinical Characteristics of HIV+ Children at Study Entry

Characteristic ValueCDC Stage, N (%) N/A 84 (44)

B 55 (29)

C 41 (21)

CD4 Count, cell/mm3 Median (IQR) 624 (463, 859)

Viral load, copies/mL (%) >5000 34 (18)

401-5000 40 (21)

<400 61 (11)

ARV Regimens (%)

HAART with PI 111 (58)

HAART without PI 30 (16)

Non-HAART ARV 10 (5)

No ARV 10 (5)

Baseline Metabolic Outcomes in HIV-Infected Children

Metabolic Outcome N Abnormal (%) Median IQR

Fasting Glucose (mg/dL) 153 86.0 81, 91

Fasting Insulin (mu/mL) 150 12.1 8.0, 20.9

HOMA-IR (normal <2.5 for Tanner 1 or <4 for Tanner 2-5)

151 29 2.5 1.7, 4.5

Total cholesterol (mg/dL) 189 15 159 137, 186

HDL-cholesterol (mg/dL) 187 10 49 41, 58

LDL-cholesterol (mg/dL) 186 11 87 72, 112

Triglycerides (mg/dL) 188 15 86.5 63, 116

Mitochondrial Function by HIV Status

Median Outcome HIV+ HEU P-value

POC lactate (mg/dL) [IQR]

1.45 [1.00, 1.90]

1.40[1.10, 1.90]

0.98

Venous lactate (mg/dL) [IQR]

1.0[0.78, 1.40]

1.26 [0.89, 1.70]

<0.001

Venous pyruvate (mg/dL) [IQR]

0.09[0.05, 0.11]

0.10[0.07, 0.13]

0.005

CI enzyme activity PBMC (OD/min/mg e-6) [IQR]

37.92 [27.73, 58.50]

36.87 [29.69, 56.87] 0.71

CIV enzyme activity PBMC (OD/min/mg e-6) [IQR]

69.38 [52.13, 83,34]

60.83 [50.59, 72.21]

0.048

Insulin Resistance is Associated with Increased Venous Lactate and Pyruvate in

HIV+ Children

_x0017_Venous Lactate (IR=Yes)

_x0016_Venous Lactate (IR=No)

_x0018_Venous Pyruvate (IR=Yes)

_x0017_Venous Pyruvate (IR=No)

0tan28a566028

0tan29a566029

0tan1a56601

0tan2a56602Ve

nous

Lac

tate

and

Pyr

uvat

e (m

mol

/L)

IR - YES IR - YESIR – NO IR – NO

Lactate Pyruvate

Hypertriglyceridemia is Associated with Point-of-Care (POC) and Venous Lactate in HIV+

Children

_x001d_POC Lactate (High TG = YES)

_x001b_POC Lactate (High TG = No)

_x001e_Venous Lactate (High TG = YES)

_x001d_Venous Lactate (High TG = No)

0tan28a566028

0tan29a566029

0tan1a56601

0tan2a56602

0tan3a56603PO

C an

d Ve

nous

Lac

tate

(mm

ol/L

)

High TG Normal TG High TG Normal TG

POC Lactate Venous Lactate

P=0.024 P<0.001

Low HDL-Cholesterol is Associated with Lower PBMC OXPHOS CI and CIV Enzyme Activities in

HIV+ Children

!CI Activity PBMCs (Low HDL = Yes) CI Activity PBMCs (Low HDL = No) "CIV Activity PBMCs (Low HDL = Yes)

!CIV Activity PBMCs (Low HDL = No)

0tan28a566028

0tan19a566019

0tan9a56609

0tan29a566029

0tan19a566019

0tan10a566010

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0tan20a566020

CI (O

D/m

in/u

g e-

6) a

nd C

IV (O

D/m

in/u

g e-

5) A

ctiv

-iti

es in

PBM

Cs

Low HDL Normal HDL Low HDL Normal HDL

Complex I Complex IV

P=0.024

P=0.085

Venous Lactate is Positively Correlated with Total Cholesterol in HIV+ Children

P=0.04; r=0.16

0tan28a566028 0tan29a566029 0tan1a56601 0tan2a56602 0tan3a566030tan28a566028

0tan19a566019

0tan10a566010

0tan1a56601

0tan21a566021

0tan12a566012

0tan3a56613

0tan23a566123

Venous Lactate (mmol/L)

Tota

l Cho

lest

erol

(mg/

dL)

Venous Lactate is Positively Correlated with Triglycerides in HIV+ Children

0tan28a566028 0tan29a566029 0tan1a56601 0tan2a56602 0tan3a566030tan28a566028

0tan19a566019

0tan10a566010

0tan1a56601

0tan21a566021

0tan12a566012

0tan3a56613

0tan23a566123

0tan14a566114

0tan5a56615

Venous Lactate (mmol/L)

Fasti

ng T

rigl

ycer

ide

(mg/

dL)

P<0.0001; r=0.37

Multivariable Model for HDL-Cholesterol in HIV+Children

Effect Estimate SE P-value

Gender (male) 0.42 2.42 0.86

Age (per year) -0.73 0.44 0.10

Viral load (per copy/mL) -0.00009 0.00003 0.010

Venous lactate (mg/dL) -1.75 1.18 0.14

Multivariable Model for Triglycerides in HIV+ Children

Effect Estimate SE P-value

Gender (male) 8.34 11.1 0.45

Age (per year) -2.58 2.12 0.22

PI duration (per year) 2.63 1.21 0.03

NNRTI duration (per year) 4.19 1.42 0.004

Venous lactate (per mg/dL) 17.7 5.19 0.0008

Conclusions in HIV+ Children

• Insulin resistance is associated with higher lactate and pyruvate levels

• Hypertriglyceridemia is associated with higher lactate levels

• Low HDL-cholesterol is associated with lower CI and CIV enzyme activities

• Venous lactate is independently associated with higher triglyceride levels

Overall Conclusions

Mitochondrial dysfunction induced by either HIV or ARV may be responsible for the

observed metabolic changes

Acknowledgments

We thank the study participants, PHACS Community Advisory Board, Frontier Science Inc., and Westat.

PHACS is funded by:

Under cooperative agreements with Harvard School of Public Health (HD052102, 3 U01 HD052102-05S1, 3 U01 HD052102-06S3) and Tulane School of Medicine (HD052104, 3U01HD052104-06S1)

• The following institutions participated in conducting PHACS in 2011:

•Baylor College of Medicine•Bronx Lebanon Hospital Center•Children's Diagnostic & Treatment Center•Children’s Hospital, Boston•Children’s Memorial Hospital•Jacobi Medical Center•New York University School of Medicine•St. Christopher’s Hospital for Children•St. Jude Children's Research Hospital•San Juan Hospital/Department of Pediatrics•SUNY Downstate Medical Center

•Tulane University Health Sciences Center•University of Alabama, Birmingham•University of California, San Diego•University of Colorado Health Sciences Center•University of Florida/Jacksonville•University of Illinois, Chicago•University of Medicine and Dentistry of New Jersey•University of Miami•University of Southern California•University of Puerto Rico Medical Center

Acknowledgments

Funding for this study is from DHHS/NIH/NINR grant R0112885 to M. Gerschensonand T.L. Miller. We also acknowledge the support from the John A. Burns School of

Medicine, University of Hawaii at Manoa.