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Logo of nihpaAbout Author manuscriptsSubmit a manuscriptNIH Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
Pediatrics. Author manuscript; available in PMC Jul 15, 2010.
Published in final edited form as:
PMCID: PMC2904486
NIHMSID: NIHMS200736

Antiretroviral Exposure and Lymphocyte mtDNA Content Among Uninfected Infants of HIV-1-Infected Women

Abstract

OBJECTIVE

Concern for potential adverse effects of antiretroviral (ARV) chemotherapy used to prevent mother-to-child HIV transmission has led the US Public Health Service to recommend long-term follow-up of ARV-exposed children. Nucleoside reverse transcriptase inhibitor ARV agents can inhibit DNA polymerase γ, impairing mitochondrial DNA (mtDNA) synthesis and resulting in depletion or dysfunction.

METHODS

We measured the mtDNA content of stored peripheral blood mononuclear cells (PBMCs) of 411 healthy children who were born to HIV-uninfected women and 213 uninfected infants who were born to HIV-infected women with or without in utero and neonatal ARV exposure. Cryopreserved PBMC mtDNA was quantified by using the Primagen Retina Mitox assay.

RESULTS

Geometric mean PBMC mtDNA levels were lower at birth in infants who were born to HIV-infected women. Among HIV-exposed children, mtDNA levels were lowest in those who were not exposed to ARVs, higher in those with exposure to zidovudine alone, and higher still in those with combination nucleoside reverse transcriptase inhibitor exposure. A similar pattern was observed in the corresponding women. Levels of mtDNA increased during the first 5 years of life in all HIV-exposed children but achieved normal levels only in those with ARV exposure.

CONCLUSIONS

Levels of mtDNA are lower than normal in HIV-exposed children. Contrary to expectation, PBMC mtDNA levels are significantly higher in ARV-exposed, HIV-uninfected infants and their infected mothers compared with ARV-unexposed infants and women. By 5 years, levels of PBMC mtDNA rise to normal concentrations in ARV-exposed children but remain depressed in ARV-unexposed children.

Keywords: HIV, mitochondria, antiretroviral agents

All recommended antiretroviral (ARV) regimens to prevent mother-to-child transmission include zidovudine (ZDV), a nucleoside reverse transcriptase inhibitor (NRTI). NRTIs readily cross the placental and inhibit DNA polymerase γ, potentially interfering with fetal mitochondrial DNA (mtDNA) synthesis, resulting in mitochondrial depletion and/or dysfunction.1 ARV-associated decreases in mtDNA have been reported, but correlations with mitochondrial disease have been inconsistent. 29

ARV exposure in utero has been associated with short-term and long-term mitochondrial dysfunction1013 and with lower levels of blood mtDNA.1416 Although large epidemiologic studies have found the incidence of clinically obvious mitochondrial disease rare,1720 such reports are remarkably consistent with effects observed in vitro and in fetal monkeys.2123 Studies of HIV-uninfected populations indicated that abnormal fetal growth is associated with lower peripheral blood mononuclear cell (PBMC) mtDNA levels, 24 suggesting that these levels may be a marker of in utero stress. Thus, concerns about in utero ARV exposure and mtDNA persist.

We measured PBMC mtDNA levels in HIV-positive mothers, in their HIV-uninfected infants, and in a comparison group of children who were born to healthy women. Our investigation was designed to evaluate the effects on infant PBMC mtDNA levels of maternal HIV infection and fetal and neonatal ARV exposure.

METHODS

Study Population

Samples from HIV-positive women and their uninfected infants were selected from participants in the National Institutes of Health Women and Infants Transmission study (WITS).25 Infection status was determined according to the WITS protocol.26 Samples were selected to reflect differential use of ARVs in pregnancy: no ARV exposure, exposure to ZDV alone, and exposure to combination ZDV and lamivudine with or without additional antiretrovirals (combination ARV [cARV]). From among subject pairs who met the selection criteria and had sufficient stored material available, efforts were made to balance within each time period the numbers with ARV exposure during the third trimester only, during the second and third trimesters only, or during all 3. No matching criteria were applied. The sample size of ~70 per group was established to provide 90% power to detect a 40% reduction in infant PBMC mtDNA in a 3-group comparison. Samples from healthy children who were born to HIV-uninfected women were obtained from an observational, cross-sectional study (P1009) of lymphocyte subsets in children aged 0 to 18 years conducted at sites that included all of the WITS centers.27

Sample Collection and Processing

Blood from subjects in the WITS was collected with heparin anticoagulant before 1998, after which acid-citrate-dextrose solution B (ACD-B) was used. In P1009, EDTA anticoagulant was used. Both studies used identical protocols for processing, freezing, and storage of PBMCs.28

Quantification of mtDNA

mtDNA was measured by a single reference laboratory (Quest Diagnostics Nichols Institute, San Juan Capistrano, CA) that was blind to subject exposure status, using the Primagen MITOX assay (Amsterdam, Netherlands) according to the manufacturer’s instructions. PBMC specimens were washed twice and pelleted before nucleic acid extraction. This method removes contaminating platelets.29 Blinded duplicate samples were analyzed at Primagen to confirm results and ensure lack of platelet contamination.

MITOX measures cellular mtDNA levels by using a real-time duplex nucleic acid sequence– based amplification assay, in which mtDNA and nuclear DNA (nDNA) are amplified simultaneously in a single tube to maximize assay precision. Cellular mtDNA content is calculated as the ratio of mtDNA over nDNA and expressed as mtDNA copies per cell.29

Statistical Analysis

Statistical analyses were performed by using SAS (Cary, NC). The χ2 statistic was used for comparisons of proportions. Means were compared using the F test or t test as appropriate. For all statistical analyses, mtDNA values were logarithmically transformed. All results are reported as geometric mean values. Longitudinal data comparing age trends of mtDNA levels were analyzed by using the Proc Mixed procedure.30,31 Statistical comparisons assume a 2-tailed test with .05 α.

RESULTS

Characteristics of Cohorts

Stored PBMCs were available on 213 mother-infant pairs with different ARV exposures: 71 were ARV-naive, 71 received ZDV alone, and 71 received cARV. No infant whose mother was ARV-naive received ARV. All infants whose mother received ARV also received ZDV for the first 6 weeks of life. No ARV-exposed child had clinical mitochondrial disease. Specific maternal ARV use reflected temporal changes in recommendations of prevention of mother-to-child transmission.32 More than 90% (n = 65) of the HIV-positive women who received no ARV enrolled before March 1994. Women who received ZDV alone enrolled after March 1, 1994. All women but 1 who received cARV enrolled after August 1, 1996.

A demographic and clinical comparison among the 3 groups is presented in Table 1. No significant differences are present with respect to maternal age, race/ethnicity, Centers for Disease Control and Prevention HIV disease classification, or smoking. ARV-naive women had significantly higher CD4+ T-cell counts before delivery compared with women who were taking ZDV or cARV (626 vs 486 vs 448; P = .018), but the proportion with absolute CD4+ T-cell counts <200/µL did not differ significantly. Plasma HIV RNA levels before and at delivery were lower in women who were taking cARV.

TABLE 1
Demographic and Clinical Characteristics of WITS Maternal and Infant Study Subjects According to ARV Exposure Category

Use of “hard drugs” (cocaine, crack, heroin, methadone, or injection drug use) was significantly different among the 3 groups (P < .001) and was highest in the ARV-naive group, consistent with temporal trends in drug use. Likewise, alcohol use was greatest in the no ARV group and least in the cARV group, but the difference was not statistically significant. Despite differences in hard drug use, frequencies of preterm (<37 weeks’ gestation) birth were not significantly different among groups, and infant birth weight tended to be greater in the ARV-naive group (P = .052).

Prenatal cARV Exposures

ZDV and lamivudine were the only ARVs received by 30 of 71 women in the cARV group. Nineteen women in this group received other dideoxynucleosides in addition to ZDV/lamivudine: 10 received stavudine, 4 received zalcitabine, 3 received didanosine, and 2 received both didanosine and stavudine (Table 2). The additional dideoxynucleoside exposure occurred during all 3 trimesters in 16 of 19 subjects. Nearly one half (33 of 71) of the women received a protease inhibitor, most frequently nelfinavir (22 of 33). Approximately 40% (13 of 33) of women who were treated with protease inhibitors received them through all trimesters of pregnancy.

TABLE 2
Prenatal Combination ARV Regimens Among Women Who Received ZDV/Lamivudine

Levels of mtDNA in Healthy Children

Levels of PBMC mtDNA were determined in 411 healthy, HIV-unexposed children who were aged birth to 18 years and participated in P1009.27 Approximately half (48.9%) of the subjects were female; 56% were black, 33% were Hispanic, and 8% were white non-Hispanic. There were no age-related differences in PBMC mtDNA levels (P = .87; Fig 1). The overall distribution of their mtDNA values was used as the healthy control reference.

FIGURE 1
Levels of mtDNA in the PBMCs of 411 healthy children who were born to HIV-uninfected women. Shown is a scatterplot of PBMC mtDNA levels on a logarithmic scale in healthy children, according to age. Each circle represents a single individual; the solid ...

Levels of mtDNA at Birth

Figure 2 depicts levels of mtDNA in the PBMCs among 4 groups of HIV-uninfected children: (1) healthy children who were born to HIV-uninfected women (controls), (2) infants who were born to HIV-positive women and did not receive ARVs (no ARV), (3) infants who were born to HIV-positive women and were exposed in utero and postpartum to ZDV alone (ZDV), or (4) infants were exposed in utero to cARV (ZDV/lamivudine). Children who were exposed neither to HIV nor ARVs had the highest levels of mtDNA (528 copies per cell) compared with all other groups (P < .001). Among infants whose mother had HIV infection, levels of mtDNA at birth were higher in those who were exposed to ARVs (cARV: 321 copies per cell [P < .001]; ZDV alone: 268 copies per cell [P = .01]) compared with those who were not exposed to ARVs (197 copies per cell).

FIGURE 2
Box-and-whisker plots on a logarithmic scale of PBMC mtDNA levels in healthy children and in HIV-exposed, uninfected children, according to exposure category and age. Upper and lower box borders represent the 75th and 25th percentiles, solid lines represent ...

Effect of Duration of In Utero ARV Exposure on mtDNA Levels at Birth

We compared infant PBMC mtDNA levels at birth according to the duration of gestational ARV exposure. Exposure to cARV was associated with significantly higher mtDNA levels in all in utero exposure duration subcategories than children without ARV exposure (Table 3). Children who were exposed to ZDV alone, regardless of duration, had levels closer to ARV-unexposed children. Duration of ARV exposure was not associated with significantly different levels of mtDNA within any exposure category.

TABLE 3
Infant PBMC mtDNA Levels at Birth According to ARV Exposure Category and Duration

Levels of mtDNA at 2 and 5 Years of Age

To determine whether effects on infant mtDNA persisted, we analyzed mtDNA levels in HIV-exposed children from PBMC specimens collected at 2 and 5 years of age (Fig 2). Samples were available on all children at 2 years of age and on 53 children at 5 years of age. In contrast to control subjects, mtDNA levels in HIV-exposed children increased with age regardless of the specific ARV exposure. Children who were exposed to cARV had the highest levels, whereas those who were not exposed to ARV had the lowest, at all time points (birth: P < .001; 2 years: P = .002; 5 years: P < .001). Children who were exposed to ZDV alone had intermediate values at all time points. By 5 years, ARV-exposed children had levels comparable to those of control subjects. The rate of increase in PBMC mtDNA with age differed by exposure group. During the first 5 years, the annual increase in mtDNA was ~30 copies per cell in ARV-unexposed children and 60 copies per cell ARV-exposed children.

Maternal PBMC mtDNA Levels

Levels of PBMC mtDNA in HIV-positive women varied according to ARV exposure in a manner similar to their infants: ARV-naive women had the lowest levels of mtDNA (218 copies per cell), and those who were taking cARV had the highest (317 copies per cell; P = .0007). Women who were taking ZDV alone had intermediate levels (278 copies per cell), which were significantly greater than in the ARV-naive group (P = .027) but not significantly different from women who were taking cARV (P = .23). Maternal and infant mtDNA levels at birth were significantly but loosely correlated in all groups, with only 19% of the variability in infant mtDNA levels explained by maternal mtDNA level (P < .0001, R2 = 0.19).

Other Maternal and Infant Characteristics Associated with Infant mtDNA Levels

We used a mixed-model analysis of variance to examine the effects of the following maternal and infant variables on infant mtDNA: ARV exposure, maternal alcohol use, maternal cocaine/crack use, maternal hard drug use, maternal predelivery CD4 count, maternal predelivery plasma HIV RNA, maternal delivery CD4 count, maternal delivery CD4%, maternal delivery HIV RNA level, infant birth weight, and infant age. Only ARV exposure (ZDV alone: P = .0011; ZDV/lamivudine cART: P = .0001), infant age (β = .2260; P =.0001 at 5 years), and maternal CD4 count before delivery (β = .0002; P = .0002) were significantly associated with infant mtDNA levels. Maternal illicit drug use was not associated with infant mtDNA levels.

Effect of Freeze-Thaw and Anticoagulant

Specimens that were used in this study were collected by using various anticoagulants and stored for various lengths of time. Longer storage could be associated with DNA degradation, particularly if samples inadvertently were subjected to cycles of freezing and thawing.

To determine whether PBMCs that were collected with heparin or ACD-B differed in measured mtDNA content at baseline or after 2 freeze-thaw cycles, we compared in a blinded manner 45 samples from 13 healthy, HIV-uninfected volunteers. Although there was no significant difference in mtDNA content between paired heparin- and ACD-B– collected specimens at baseline, there was a nonsignificant trend for samples that were collected with heparin to have higher mtDNA levels after 2 freeze-thaw cycles.

DISCUSSION

We quantified PBMC mtDNA levels in 213 HIV-uninfected infants who were born to HIV-positive women (the study group) and 411 healthy children who were born to uninfected women (the control group). Children with in utero and neonatal exposure to ARVs had lower levels of mtDNA at birth compared with healthy children. These data confirm and extend earlier, smaller studies of humans and animals. 14,15,22,33 In contrast to previous reports, our study included large numbers of children who were born to HIV-positive women who did not receive ARVs during pregnancy, and levels of mtDNA in these children exhibited even greater reductions. Contrary to our original hypothesis, levels of mtDNA in children who were born to untreated HIV-positive women were significantly lower than those who were exposed to ARVs. Moreover, children who were exposed to ZDV alone had lower levels of mtDNA compared with those who were exposed to cARV, suggesting that more potent ARV exposures have greater salutary effects on infant mtDNA levels.

HIV infection itself has been associated with decreased mtDNA levels and mitochondrial dysfunction in many tissue types, including PBMCs.8,3436 The mechanisms by which this occurs are undefined but may involve altered mitochondrial membrane permeability by HIV proteins,37 oxidative stress,2 and/or a proinflammatory milieu.38 Studies indicate that short-term ARV exposure in children and adults is associated with increases in mtDNA, whereas prolonged exposure—particularly to dideoxynucleosides (zalcitabine, stavudine, and didanosine)—results in marked decreases in mtDNA.2,4,29,39,40 This suggests that ARVs initially counteract the deleterious effects of HIV infection on mtDNA. The differences in maternal mtDNA that were observed in our study are consistent with this model; however, none of the children in our study was HIV-positive, and this mechanism cannot be invoked to explain the salutary effects of ARVs on their mtDNA.

Although maternal and infant mtDNA levels in our study were significantly associated, the correlation was poor, indicating that infant mtDNA levels may be related to other factors and not simply reflective of maternal levels. In HIV-uninfected subjects, there was no correlation between infant and maternal PBMC mtDNA content, but infants with abnormal birth weight (small or large for gestation age) had lower cord PBMC mtDNA compared with infants who were born with appropriate weight for gestational age.24 In our study, there was no difference among groups in the number of infants who were small or large for gestational age; however, adverse intrauterine environments have long been associated with programming effects on tissue morphology and function.41 The HIV-positive ARV-naive women in our study had high CD4-positive T-cell counts (> 600 cells per µL), and the birth weight of their children was slightly greater than that of the ARV-exposed children. This suggests that the observed effect of ARVs on mtDNA is not associated with gross differences in fetal nutrition and may reflect other intrauterine disturbances. Protein malnutrition during fetal life has been associated with decreased mtDNA content42 and is believed to be a consequence of mitochondrial damage as a result of oxidative stress.43,44 Oxidative stress also has been suggested as a mechanism of HIV-induced mtDNA depletion, which is reversed with ARVs. This may be a mechanism by which maternal health affects infant mtDNA.

When stratified by duration of intrauterine exposure, birth mtDNA levels within each intrauterine exposure duration subcategory in the cARV group (but not the ZDV alone group) were significantly higher compared with HIV-exposed infants without ARV exposure. Among infants who were exposed to cARV, mtDNA levels were higher (but not statistically significantly different) in those with shorter exposures; however, most infants (19 of 25) who were exposed to ARVs during all 3 trimesters were exposed to additional dideoxynucleosides, whereas only 3 of 46 infants with shorter exposures were on these agents. Although not possible to dissociate the effects of duration of exposure and individual drug effects, it is striking that mtDNA levels were significantly higher in infants with relatively prolonged exposure to dideoxynucleoside drugs. This suggests that unchecked maternal HIV replication is more deleterious to infant mtDNA than prolonged fetal ARV exposure.

Levels of PBMC mtDNA increased in HIV-exposed children at a slow, seemingly constant rate during the first few years of life. By 5 years, mtDNA levels were normal in ARV-exposed children but remained significantly reduced in the ARV-unexposed children. In contrast, mtDNA levels in our control group did not vary with age, suggesting that this increase in mtDNA levels among HIV-exposed children represented recovery from intrauterine or perinatal insult. The rate of increase of 60 copies per cell per year in our subjects is within the range reported in adults and children who started on ARVs.2,40

The strengths and limitations of this study merit consideration. It is the largest longitudinal study of mtDNA in HIV-exposed, uninfected children with variable ARV exposure. Given myriad effects of HIV on maternal health, the inclusion of an ARV-naive group is an additional major strength. Another strength is the reference control group of healthy children who were born to HIV-uninfected women. In addition, all mtDNA levels were analyzed by a blinded single laboratory by using a validated assay that minimized platelet contamination, thereby ensuring accurate and nonbiased assessment.

Several limitations exist, however. Given the observational nature of our study, we cannot determine a causal relationship between ARVs and mtDNA levels. Like all observational studies, our study may be confounded by secular trends and lack of randomization. We did consider and adjust for a large number of potential confounders in analysis. Nonetheless, that possible residual confounding affected our results cannot be excluded. In addition, specimens from untreated women were stored in liquid nitrogen vapor longer than those from subjects who were exposed to ARVs. Although our studies did not detect significant differences in mtDNA with repeated freeze-thaw cycles, it is theoretically possible that prolonged storage is associated with effects not related to temperature variation. As with most new diagnostic laboratory technologies, experimental data on analyte stability in long-term storage are lacking. A loss on the order of 0.03 log10 mtDNA copies per cell per year of storage could negate our findings; however, nDNA is believed to be more vulnerable to degradation compared with mtDNA as a result of differences in size, location, and conformation.45 Because our measurement of mtDNA was obtained by using the ratio of mtDNA to nDNA, time-dependent degradation, if it existed, theoretically would lower nDNA levels more than mtDNA levels, thereby increasing rather than decreasing the observed number of mtDNA copies per cell.

Only 11% of the children in the WITS were exposed to protease inhibitors, all received prenatal care, and their mother’s CD4 counts were high, potentially limiting generalizability of our findings to populations that are treated with those regimens.

Finally, the clinical significance of decreased mtDNA levels in PBMCs is uncertain. ARV-induced depletion of PBMC mtDNA levels tends to be associated with clinical manifestations of mitochondrial toxicity but is not per se an adequate proxy for symptomatology or mtDNA content of other tissues.29,46,47 None of the children in this study had clinical symptoms consistent with mitochondrial dysfunction, despite markedly lower levels of mtDNA after many years; however, the long-term consequences of decreased mtDNA levels are unknown. In HIV-uninfected populations, decreased PBMC mtDNA has been implicated in the development of type 2 diabetes, and with metabolic syndrome in adulthood.42,48

Despite these caveats, our data suggest that uncontrolled maternal HIV infection and ARV exposure have significant opposing, prolonged effects on the developing fetus. The net result of these effects on infant mtDNA levels depends on both duration and type of ARV exposure, but, overall, short-term ARV exposure seems to be beneficial.

CONCLUSIONS

Our data highlight the potential fetal adverse effects of uncontrolled maternal HIV replication and the need for continued surveillance and other investigations to monitor effects of in utero HIV and ARV exposure.

WHAT’S KNOWN ON THIS SUBJECT

Results of in vitro and animal studies have suggested that in utero exposure to ARVs decreases mitochondria. Decreases in mtDNA have been reported in ARV-exposed infants, but correlations with mitochondrial disease have been inconsistent.

WHAT THIS STUDY ADDS

In contrast to other studies, we included children who were born to HIV-infected women who did not receive ARV as well as those who received ZDV alone or in combination with other drugs, and we quantified mtDNA in normal healthy children.

ACKNOWLEDGMENTS

The WITS was funded by National Institutes of Health (NIH) grants U01 AI 34858, 9U01 DA 15054, U01 DA 15053, HD-3-6117, U01 AI 34841, U01 HD 41983, N01 AI 85339, and U01 AI 50274–01, with additional support from the local clinical research centers as follows: Baylor College of Medicine (Houston, TX), NIH GCRC RR00188; Columbia University (New York, NY), NIH GCRC RR00645. The P1009 study was funded by NIH grants U01 AI27551, R01 AI94029, P30 AI36211, U01 AI41110, U01 AI 27550, U01 AI 27541, U01 AI32921, U01 AI41089, U01 AI32907, U01 AI27559, U01 AI41089, M01 RR-00188, M01 RR-00865, M01 RR-01271, M01 RR-00240, and N01 HD33162 and by the American Academy of Allergy Asthma & Immunology Basic and Clinical Immunology Interest Section Research Award (to Dr Shearer). Independent funding for mtDNA testing was provided by an unrestricted grant from GlaxoSmithKline (Research Triangle Park, NC) to Childrens Hospital Los Angeles.

The WITS principal investigators, study coordinators, and program officers include the following: Clemente Diaz and Edna Pacheco-Acosta (University of Puerto Rico, San Juan, PR); Ruth Tuomala, Ellen Cooper, and Donna Mesthene (Boston/Worcester Site, Boston, MA); Jane Pitt (deceased) and Alice Higgins (Columbia Presbyterian Hospital, New York, NY); Sheldon Landesman, Edward Handelsman, and Gail Moroso (deceased; State University of New York, Brooklyn, NY); Kenneth Rich and Delmyra Turpin (University of Illinois, Chicago, IL); William Shearer, Susan Pacheco, and Norma Cooper (Baylor College of Medicine, Houston, TX); Samuel Adeniyi-Jones and Joana Rosario (National Institute of Allergy and Infectious Diseases, Bethesda, MD); Robert Nugent (Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD); Vincent Smeriglio and Katherine Davenny (National Institute on Drug Abuse, Bethesda, MD); and Bruce Thompson (Clinical Trials & Surveys Corp, Baltimore, MD). Scientific Leadership Core: Kenneth Rich. Additional support has been provided by local clinical research centers as follows: Baylor College of Medicine and Columbia University.

We thank all the women and children who participated in these studies and acknowledge the laboratory support of W. Don Decker and Danielle Paschal and the excellent technical assistance of Hasnah Hamdan, Amy Cruikshank, Justin Guan, and Joy Whetstone of the Quest Diagnostics Nichols Institute (San Juan Capistrano, CA) facility for performance of the mtDNA assay determinations reported in this study. We also thank Michel de Baar of Primagen for useful discussions and performing additional studies.

ABBREVIATIONS

ARV
antiretroviral
ZDV
zidovudine
NRTI
nucleoside reverse transcriptase inhibitor
mtDNA
mitochondrial DNA
PBMC
peripheral blood mononuclear cell
WITS
Women and Infants Transmission Study
cARV
combination antiretroviral
ACD-B
acid-citrate-dextrose solution B
nDNA
nuclear DNA

Footnotes

This work was presented in part at the 13th Conference on Retroviruses and Opportunistic Infections; February 5–9, 2006; (abstract S-107).

FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.

Reprints Information about ordering reprints can be found online:http://www.pediatrics.org/misc/reprints.shtml

REFERENCES

1. Lewis W, Dalakas MC. Mitochondrial toxicity of antiviral drugs. Nat Med. 1995;1(5):417–422. [PubMed]
2. Casula M, Weverling GJ, Wit FW, et al. Mitochondrial DNA and RNA increase in peripheral blood mononuclear cells from HIV-1- infected patients randomized to receive stavudine-containing or stavudine-sparing combination therapy. J Infect Dis. 2005;192(10):1794–1800. [PubMed]
3. Cossarizza A, Pinti M, Moretti L, et al. Mitochondrial functionality and mitochondrial DNA content in lymphocytes of vertically infected human immunodeficiency virus-positive children with highly active antiretroviral therapy-related lipodystrophy. J Infect Dis. 2002;185(3):299–305. [PubMed]
4. de Mendoza C, de Ronde A, Smolders K, et al. Changes in mitochondrial DNA copy number in blood cells from HIV-infected patients undergoing antiretroviral therapy. AIDS Res Hum Retroviruses. 2004;20(3):271–273. [PubMed]
5. López S, Miro O, Martinez E, et al. Mitochondrial effects of antiretroviral therapies in asymptomatic patients. Antivir Ther. 2004;9(1):47–55. [PubMed]
6. Maagaard A, Holberg-Petersen M, Kollberg G, Oldfors A, Sandvik L, Bruun JN. Mitochondrial (mt)DNA changes in tissue may not be reflected by depletion of mtDNA in peripheral blood mononuclear cells in HIV-infected patients. Antivir Ther. 2006;11(5):601–608. [PubMed]
7. Petit C, Mathez D, Barthelemy C, et al. Quantitation of blood lymphocyte mitochondrial DNA for the monitoring of antiretroviral drug-induced mitochondrial DNA depletion. J Acquir Immune Defic Syndr. 2003;33(4):461–469. [PubMed]
8. Côté HC, Brumme ZL, Craib KJ, et al. Changes in mitochondrial DNA as a marker of nucleoside toxicity in HIV-infected patients. N Engl J Med. 2002;346(11):811–820. [PubMed]
9. McComsey G, Bai RK, Maa JF, Seekins D, Wong LJ. Extensive investigations of mitochondrial DNA genome in treated HIV-infected subjects: beyond mitochondrial DNA depletion. J Acquir Immune Defic Syndr. 2005;39(2):181–188. [PubMed]
10. Blanche S, Tardieu M, Rustin P, et al. Persistent mitochondrial dysfunction and perinatal exposure to antiretroviral nucleoside analogues. Lancet. 1999;354(9184):1084–1089. [PubMed]
11. Barret B, Tardieu M, Rustin P, et al. Persistent mitochondrial dysfunction in HIV-1- exposed but uninfected infants: clinical screening in a large prospective cohort. AIDS. 2003;17(12):1769–1785. [PubMed]
12. Brogly SB, Ylitalo N, Mofenson LM, et al. In utero nucleoside reverse transcriptase inhibitor exposure and signs of possible mitochondrial dysfunction in HIV-uninfected children. AIDS. 2007;21(8):929–938. [PubMed]
13. Tovo PA, Chiapello N, Gabiano C, Zeviani M, Spada M. Zidovudine administration during pregnancy and mitochondrial disease in the offspring. Antivir Ther. 2005;10(6):697–699. [PubMed]
14. Shiramizu B, Shikuma KM, Kamemoto L, et al. Placenta and cord blood mitochondrial DNA toxicity in HIV-infected women receiving nucleoside reverse transcriptase inhibitors during pregnancy. J Acquir Immune Defic Syndr. 2003;32(4):370–374. [PubMed]
15. Divi RL, Walker VE, Wade NA, et al. Mitochondrial damage and DNA depletion in cord blood and umbilical cord from infants exposed in utero to Combivir. AIDS. 2004;18(7):1013–1021. [PubMed]
16. Poirier MC, Divi RL, Al-Harthi L, et al. Long-term mitochondrial toxicity in HIV-uninfected infants born to HIV-infected mothers. J Acquir Immune Defic Syndr. 2003;33(2):175–183. [PubMed]
17. Bulterys M, Nesheim S, Abrams EJ, et al. Lack of evidence of mitochondrial dysfunction in the offspring of HIV-infected women: retrospective review of perinatal exposure to antiretroviral drugs in the Perinatal AIDS Collaborative Transmission Study. Ann N Y Acad Sci. 2000;918:212–221. [PubMed]
18. Lindegren ML, Rhodes P, Gordon L, Fleming P. Drug safety during pregnancy and in infants: lack of mortality related to mito-chondrial dysfunction among perinatally HIV-exposed children in pediatric HIV surveillance. Ann N Y Acad Sci. 2000;918:222–235. [PubMed]
19. Dominguez K, Bertolli J, Fowler M, et al. Lack of definitive severe mitochondrial signs and symptoms among deceased HIV-uninfected and HIV-indeterminate children ≤ 5 years of age, Pediatric Spectrum of HIV Disease project (PSD), USA. Ann N Y Acad Sci. 2000;918:236–246. [PubMed]
20. Culnane M, Fowler M, Lee SS, et al. Pediatric AIDS Clinical Trials Group Protocol 219/076 Teams. Lack of long-term effects of in utero exposure to zidovudine among uninfected children born to HIV-infected women. JAMA. 1999;281(2):151–157. [PubMed]
21. Gerschenson M, Erhart SW, Paik CY, et al. Fetal mitochondrial heart and skeletal muscle damage in Erythrocebus patas monkeys exposed in utero to 3′-azido-3′ - deoxythymidine. AIDS Res Hum Retroviruses. 2000;16(7):635–644. [PubMed]
22. Gerschenson M, Nguyen V, Ewings EL, et al. Mitochondrial toxicity in fetal Erythrocebus patas monkeys exposed transplacentally to zidovudine plus lamivudine. AIDS Res Hum Retroviruses. 2004;20(1):91–100. [PubMed]
23. Gerschenson M, Poirier MC. Fetal patas monkeys sustain mitochondrial toxicity as a result of in utero zidovudine exposure. Ann N Y Acad Sci. 2000;918:269–281. [PubMed]
24. Gemma C, Sookoian S, Alvarinas J, et al. Mitochondrial DNA depletion in small- and large-for-gestational-age newborns. Obesity (Silver Spring) 2006;14(12):2193–2199. [PubMed]
25. Sheon AR, Fox HE, Rich KC, et al. The Women and Infants Transmission Study (WITS) of maternal-infant HIV transmission: study design, methods and baseline data. J Womens Health. 1996;5(1):69–78.
26. Bremer JW, Lew JF, Cooper E, et al. Diagnosis of infection with human immunodeficiency virus type 1 by a DNA polymerase chain reaction assay among infants enrolled in the Women and Infants’ Transmission Study. J Pediatr. 1996;129(2):198–207. [PubMed]
27. Shearer WT, Rosenblatt HM, Gelman RS, et al. Lymphocyte subsets in healthy children from birth through 18 years of age: the Pediatric AIDS Clinical Trials Group P1009 study. J Allergy Clin Immunol. 2003;112(5):973–980. [PubMed]
28. ACTG/IMPACT Lab Manual. 2008. [Accessed October 21, 2009]. Available at: www.hanc.info/labs/Pages/actgimpaactlabmanual.aspx.
29. Timmermans EC, Tebas P, Ruiter JP, Wanders RJ, de Ronde A, de Baar MP. Real-time nucleic acid sequence-based amplification assay to quantify changes in mitochondrial DNA concentrations in cell cultures and blood cells from HIV-infected patients receiving antiviral therapy. Clin Chem. 2006;52(6):979–987. [PubMed]
30. Laird N, Ware J. Random-effects models for longitudinal data. Biometrics. 1982;38(4):963–974. [PubMed]
31. Wolfinger R. An example of using mixed models and Proc Mixed for longitudinal data. J Biopharm Stat. 1997;7(4):481–500. [PubMed]
32. Cooper ER, Charurat M, Burns DN, Blattner W, Hoff R. Trends in antiretroviral therapy and mother-infant transmission of HIV. The Women and Infants Transmission Study Group. J Acquir Immune Defic Syndr. 2000;24(1):45–47. [PubMed]
33. Divi RL, Leonard SL, Walker BL, et al. Erythrocebus patas monkey offspring exposed perinatally to NRTIs sustain skeletal muscle mitochondrial compromise at birth and at 1 year of age. Toxicol Sci. 2007;99(1):203–213. [PubMed]
34. Miró O, Lopez S, Martinez E, et al. Mitochondrial effects of HIV infection on the peripheral blood mononuclear cells of HIV-infected patients who were never treated with antiretrovirals. Clin Infect Dis. 2004;39(5):710–716. [PubMed]
35. Sternfeld T, Schmid M, Tischleder A, et al. The influence of HIV infection and antiretroviral therapy on the mitochondrial membrane potential of peripheral mononuclear cells. Antivir Ther. 2007;12(5):769–778. [PubMed]
36. Peraire J, Miro O, Saumoy M, et al. HIV-1- infected long-term non-progressors have milder mitochondrial impairment and lower mitochondrially-driven apoptosis in peripheral blood mononuclear cells than typical progressors. Curr HIV Res. 2007;5(5):467–473. [PubMed]
37. Jacotot E, Ravagnan L, Loeffler M, et al. The HIV-1 viral protein R induces apoptosis via a direct effect on the mitochondrial permeability transition pore. J Exp Med. 2000;191(1):33–46. [PMC free article] [PubMed]
38. Haugaard SB. Toxic metabolic syndrome associated with HAART. Expert Opin Drug Metab Toxicol. 2006;2(3):429–445. [PubMed]
39. Miura T, Goto M, Hosoya N, et al. Depletion of mitochondrial DNA in HIV-1-infected patients and its amelioration by antiretroviral therapy. J Med Virol. 2003;70(4):497–505. [PubMed]
40. Saitoh A, Fenton T, Alvero C, Fletcher CV, Spector SA. Impact of nucleoside reverse transcriptase inhibitors on mitochondria in HIV-1 infected children receiving HAART. Antimicrob Agents Chemother. 2007;51(12):4236–4242. [PMC free article] [PubMed]
41. Langley-Evans SC. Developmental programming of health and disease. Proc Nutr Soc. 2006;65(1):97–105. [PMC free article] [PubMed]
42. Park HK, Jin CJ, Cho YM, et al. Changes of mitochondrial DNA content in the male off-spring of protein-malnourished rats. Ann N Y Acad Sci. 2004;1011:205–216. [PubMed]
43. Huang CJ, Fwu ML. Degree of protein deficiency affects the extent of the depression of the antioxidative enzyme activities and the enhancement of tissue lipid peroxidation in rats. J Nutr. 1993;123(5):803–810. [PubMed]
44. Richter C. Reactive oxygen and DNA damage in mitochondria. Mutat Res. 1992;275(3–6):249–255. [PubMed]
45. Butler J. Forensic DNA Typing: Biology, Technology and Genetics of STR Markers. 2nd ed. Boston, MA: Elsevier Academic Press; 2005.
46. Mirô O, Lopez S, Pedrol E, et al. Mitochondrial DNA depletion and respiratory chain enzyme deficiencies are present in peripheral blood mononuclear cells of HIV-infected patients with HAART-related lipodystrophy. Antivir Ther. 2003;8(4):333–338. [PubMed]
47. McComsey GA, Paulsen DM, Lonergan JT, et al. Improvements in lipoatrophy, mitochondrial DNA levels and fat apoptosis after replacing stavudine with abacavir or zidovudine. AIDS. 2005;19(1):15–23. [PubMed]
48. Song J, Oh JY, Sung YA, Pak YK, Park KS, Lee HK. Peripheral blood mitochondrial DNA content is related to insulin sensitivity in offspring of type 2 diabetic patients. Diabetes Care. 2001;24(5):865–869. [PubMed]
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