Evaluation of Pregnancy PBMC and Placental MtDNA in HIV-infected, HAART-treated women, compared to HIV-uninfected women*

Hélène Côté*1,2, Evelyn Maan3, Eszter Papp1, Tessa Chaworth-Musters3, Izabelle Gadawski1, Julie van Schalkwyk3, Marissa Jitratkosol3, John Forbes2,3, David Burdge2,3, Deborah Money2,3, and The HIV Perinatal Study Group

1University of British Columbia; 2Women`s Health Research Institute; and 3 Oak Tree Clinic / Children`s & Women`s Health Centre of BC, Vancouver, British Columbia, Canada

948Hélène C.F. Côtéhelene.cote@ubc.caPh: 604-822-9777FAX: 604-822-7635

HIV-infected women receive HAART during pregnancy, either from the 2nd trimester until delivery, or throughout the pregnancy if indicated by CD4 count.

NRTI can cause mitochondrial toxicity and are known to cross the placenta.

This study evaluated longitudinal peripheral blood mononucleated cells (PBMC) and placental tissue mitochondrial DNA (mtDNA) levels in HIV-positive pregnancies compared to control HIV-negative pregnancies,

as well as whole blood mtDNA levels in the infants at birth.

Background

Prospective single centre cohort study.

Blood was collected in CPT tubes (BD) at 4 time periods in

all pregnancies: 13-23w of gestation (before HAART for Group A), >23-30w, >30-39w, delivery (when possible) and for HIV pregnancies, at 6w post-partum. PBMC were isolated and washed in PBS 3 times at low speed.

Whole blood was collected from infants (PKU heel prick) within 3 days of birth.

Placental tissue was collected from fetal and maternal sides shortly after delivery.

MtDNA content was measured in isolated maternal PBMC,

infant whole blood and placental tissue by real-time PCR.

Statistical analyses: Between group comparisons were done using the Mann-Whitney test. For placenta maternal vs. fetal side analyses, Wilcoxon signed-rank test and Pearson’s correlation were used.

Methods

Oak Tree Clinic

The Perinatal HIV Study Group also includes: Ariane Alimenti

ResultsGroup A: N=27 for longitudinal PBMC, N=30 for placenta,

HIV+ on HAART since 2nd trimester of pregnancy

(mostly AZT/3TC/nelfinavir HAART regimen)

Group B: N=8 for longitudinal PBMC, 7 for placenta,

HIV+ on HAART since conception (regimen varied)

Group C: N=24 for PBMC, 23 for placenta: HIV negative controls

Table 1. Placental mtDNA content.

Figure 1. Longitudinal mean ± standard error maternal PBMC mtDNA content during pregnancy.

50

100

150

200

250

300

PB

MC

mtD

NA

/nD

NA

rati

o

13-23Weeks

>23-30Weeks

>30-39Weeks

Delivery 6 weeksPost-partum

C= HIV- controls

A= HAART 2nd trimester

B= HAART conception

Period in pregnancy

50

100

150

200

250

300

13-23Weeks

>23-30Weeks

>30-39Weeks

Delivery 6 weeksPost-partum

C = HIV - controls

A = HAART 2 nd trimester

B = HAART at conception

14

5

21

22

7

22

28

8

21

17

5

20

28

8

N

N

N

Conclusions

Acknowledgements

A physiological increase in PBMC mtDNA is seen in normal pregnancy near the end of gestation, possibly to meet high energy demands. This increase appears delayed in HIV+ HAART-treated pregnancies.

In HIV+ HAART-treated pregnancies, placental mtDNA tends to be higher on the maternal side compared to the fetal side of the organ.

Changes in placental mtDNA may affect metabolism and energy production within the placenta.

Infant blood mtDNA at birth content was not different between groups.

Mitochondrial toxicity related to nucleoside therapy may have amplified consequences in a perinatal setting.

Further studies are needed to identify antiretrovirals with the least toxicity in pregnancy.

Figure 2. Comparison of placental mtDNA content between groups A and C on the maternal and fetal side.

Funding toD. Money from:

Figure 4. Correlation between placenta mtDNA content, maternal vs. fetal side.

0

50

100

150

200

250

300

0 50 100 150 200 250 300

maternal side mtDNA/nDNA

feta

l s

ide

mtD

NA

/nD

NA

Group C = HIV- controls

0

50

100

150

200

250

300

0 50 100 150 200 250 300

maternal side mtDNA/nDNA

feta

l s

ide

mtD

NA

/nD

NA

Group A = HIV+ HAART-exposed

Group N MATERNAL FETAL paired comparisons

R slope p value p value

A 30 97 ± 7 90 ± 7 0.476 0.504 0.008 0.052

B 7 81 ± 8 84 ± 15 0.719 0.359 0.069 0.938

C 23 84 ± 8 85 ± 10 0.899 1.05 <0.0001 0.223

mean ± standard error

Pearson's correlations

Placenta mtDNA/nDNA maternal vs . fetal

AN=30

0

50

100

150

200

250

Placenta maternal side

CN=23

mtD

NA

/nD

NA

P=0.058

Figure 3. Comparison of infant blood mtDNA content between groups at birth (0-3 days of age).

0

50

100

150

200

250

mtD

NA

/nD

NA

Placenta fetal side

AN=30

CN=23

P=0.563

* Values presented here are slightly different from those in the abstract as a study participant originally been placed in Group B belonged in Group A

50

100

150

200

250

300

350

Blo

od

mtD

NA

/nD

NA

AN=26

CN=19

BN=8

P=0.285

P=0.121 P=0.518