title: Quantitation of blood lymphocyte mitochondrial DNA for the monitoring of antiretroviral drug-induced mitochondrial DNA depletion.
abstract: OBJECTIVE
  To investigate the impact of antiretroviral treatment on the mitochondrial DNA (mtDNA) content of peripheral blood mononuclear cells (PBMCs) from HIV-1-infected patients.
  
  
  METHODS
  As absolute mtDNA copy numbers widely differ between individuals, we performed a longitudinal analysis where the patient's first historical specimen was obtained as a baseline reference for relative comparison with subsequent samples from that patient.
  
  
  METHODS
  mtDNA and nuclear DNA quantitation per cell (beta-globin gene copies) were both measured by real-time polymerase chain reaction analysis of whole DNA extracts of 361 serial live-cryopreserved PBMCs collected in former trials and clinical follow-ups from 60 individuals with established or recently acquired HIV-1 infections before and during administration of various antiviral combination therapies.
  
  
  RESULTS
  mtDNA amounts were stable or increasing over years of natural HIV-1 infection in untreated patients (n = 7), consistent with our finding of a lack of differences in mtDNA copy numbers in patients with either a long established or recent lentivirus infection. Our quantitation system revealed significant changes in mtDNA copy number depending on the designated triple, quadruple, or quintuple anti-HIV drug combinations. Zidovudine + zalcitabine + ritonavir and zidovudine + lamivudine + didanosine regularly lead to mtDNA depletion in each of the treated patients, whereas none of 7 patients (and 35 cell specimens) receiving a stavudine + lamivudine + indinavir combination had any significant mtDNA content variations. In 7 patients, mtDNA copy numbers returned to pretreatment levels and/or higher levels without any interruption of the previously mtDNA-depleting antiretroviral drug combination.
  
  
  CONCLUSIONS
  Our assay system allowed the detection of significant changes in the mtDNA content of PBMCs from HIV-1-infected patients taking antiretroviral drugs, as has been reported in the literature with other detection systems. Yet, mtDNA copy numbers regularly diminished during administration of some but not all nucleoside analog-containing combinations. This, plus the occasional finding that depleted mtDNA contents spontaneously increased to baseline levels and/or higher levels during uninterrupted treatment, should raise a note of caution about resorting to the PBMC mtDNA marker for monitoring of antiretroviral drug-related mitochondrial toxicities.
authors.affiliation: Laboratoire Génétique des Virus, Institut Cochin, INSERM U567, CNRS UMR 8104, Université Paris, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Petit
authors.forename: Dominique
authors.initials: D
authors.lastname: Mathez
authors.forename: Cyrille
authors.initials: C
authors.lastname: Barthélémy
authors.forename: Thierry
authors.initials: T
authors.lastname: Leste-Lasserre
authors.forename: Robert K
authors.initials: RK
authors.lastname: Naviaux
authors.forename: Pierre
authors.initials: P
authors.lastname: Sonigo
authors.forename: Jacques
authors.initials: J
authors.lastname: Leibowitch
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy* / Q000235:genetics; D000328:Adult; D019380:Anti-HIV Agents / Q000009:adverse effects*; D004272:DNA, Mitochondrial / Q000032:analysis*; D005260:Female; D018628:Gene Dosage; D015497:HIV-1; D006801:Humans; D008214:Lymphocytes / Q000737:chemistry*; D008297:Male; D008928:Mitochondria / Q000187:drug effects*
chemical_list: D019380:Anti-HIV Agents; D004272:DNA, Mitochondrial