TRANSLATIONAL RESEARCH Placental Mitochondrial Toxicity, Oxidative Stress, Apoptosis, and Adverse Perinatal Outcomes in HIV Pregnancies Under Antiretroviral Treatment Containing Zidovudine Sandra Hernández, MD,*† Marc Catalán-García, BSc,† Constanza Morén, PhD,† Laura García-Otero, MD,* Marta López, MD, PhD,* Mariona Guitart-Mampel, BSc,† José Milisenda, MD,† Oriol Coll, PhD,‡ Francesc Cardellach, PhD,† Eduard Gratacós, PhD,* Òscar Miró, PhD,† and Glòria Garrabou, PhD† Objective: To determine whether mitochondrial, oxidative, and apoptotic abnormalities in placenta derived from HIV and combined antiretroviral therapy (cART) containing zidovudine (AZT) could be associated with adverse perinatal outcome. Design: Cross-sectional, controlled, observational study. Methods: We studied obstetric results and mitochondrial, oxida- tive, and apoptotic state in placenta of 24 treated HIV-infected and 32 -uninfected pregnant women. We measured mitochondrial DNA (mtDNA) content by quantitative reverse transcriptase–polymerase chain reaction (mtND2/n18SrRNA), oxidative stress by the spec- trophotometric quantification of lipid peroxidation and apoptosis by Western blot analysis of active caspase-3 respect to b-actin content and analysis of the terminal deoxynucleotidyl transferase dUTP nick end labeling. Results: Global adverse perinatal outcome (defined as preterm delivery or/and small newborns for gestational age) was significantly increased in HIV pregnancies [or 6.7 (1.3–33.2); P , 0.05]. mtDNA content in HIV-infected women was significantly depleted (39.20% 6 2.78%) with respect to controls (0.59 6 0.03 vs. 0.97 6 0.07; P , 0.001). A significant 29.50% 6 9.14% increase in oxidative stress was found in placentas of HIV-infected women (23.23 6 1.64 vs. 17.94 6 1.03; P , 0.01). A trend toward 41.18% 6 29.41% increased apoptosis active caspase-3/b-actin was found in HIV patients (0.48 6 0.10 vs. 0.34 6 0.05; P = not significant), confirmed by transferase dUTP nick end labeling assay. Adverse perinatal outcome did not correlate mitochondrial, oxidative, or apoptotic findings. Conclusions: Placentas of HIV-infected pregnant women under AZT cART showed evidence of mtDNA depletion, increased oxidative stress levels, and apoptosis suggestive of secondary mitochondrial failure, potential base of associated adverse perinatal outcome. Despite the fact that further demonstration of causality would need new approaches and bigger sample sizes, AZT-sparing cART should be considered in the context of pregnancy. Key Words: apoptosis, cART, HIV, mitochondria, mitochondrial toxicity, mitochondrial function/dysfunction, perinatal outcome, placenta, pregnancy (J Acquir Immune Defic Syndr 2017;75:e113–e119) INTRODUCTION In maternal HIV infection, the use of combined antiretroviral therapy (cART) has dramatically decreased perinatal transmission. 1–4 Nucleoside reverse transcriptase inhibitors (NRTIs) are the main components of cART and promote their therapeutic activity by competing with the natural nucleosides, inhibiting the reverse transcriptase of the virus but, as a secondary effect, blocking the mitochondrial DNA (mtDNA) replication that may lead to mitochondrial dysfunction 5,6 and adverse clinical manifestations including hyperlactatemia, lipodystrophy, or myopathy. 7–11 It is remarkably that not all the NRTI drugs have the same intensity or capacity to produce mitochondrial toxicity, as they present different affinities for DNA-polymerase-g, the enzyme responsible of replicating and repairing mtDNA, as extensively described. 5,12 Indeed, a ranking of toxicities has been in vitro established as follows (from the most to the less harmful): 29-39-dideoxycytidine (ddC).didanosine (ddI). stavudine (d4T)..Zidovudine (AZT).lamivudine (3TC). Received for publication May 20, 2016; accepted January 16, 2017. From the *Department of Maternal-Fetal Medicine, BCNatal—Hospital Clínic, University of Barcelona, Spain and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER); †Muscle Research and Mito- chondrial Function Laboratory, Cellex IDIBAPS, Faculty of Medicine and Health Sciences, University of Barcelona, Internal Medicine Service- Hospital Clínic of Barcelona and CIBERER, Barcelona, Spain; and ‡Unit of Assisted Reproduction, Clínica Eugin, Barcelona, Spain. Fundación para la Investigación y la Prevención del SIDA en España (FIPSE 360745/09 and 360982/10), Suports a Grups de Recerca (2014/SGR/376) and CERCA programme of the Generalitat de Catalunya, Fundació Privada Cellex, Marató de TV3 [PI044005 (87C2015)], Fondo de Investigación sanitaria (FIS 01738/13, 01455/13, 00817/15 and 00903/ 15), InterCIBER (PIE 1400061) and CIBER de Enfermedades Raras (CIBERER), initiatives of ISCIII and FEDER. The authors have no conflicts of interest to disclose. S.H. and C.-G.M. have contributed equally. Correspondence to: Laura García-Otero, MD, Department of Maternal-Fetal Medicine, BCNatal—Hospital Clínic, University of Barcelona, Spain, C/ Sabino de Arana, 1 08028 Barcelona, Spain (e-mail: lagarcia@clinic.ub.es). Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved. J Acquir Immune Defic Syndr  Volume 75, Number 4, August 1, 2017 www.jaids.com | e113 Copyright Ó 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.