No evidence of mitochondrial DNA depletion in peripheral white blood cells after three to 12 months of HAART
Hammond, E., Nolan, D., McKinnon, E. and Mallal, S. (2002) No evidence of mitochondrial DNA depletion in peripheral white blood cells after three to 12 months of HAART. In: XIV International AIDS conference, 7 - 12 July 2002, Barcelona, Spain
Background: Anti-retroviral therapy is associated with decreased mitochondrial DNA (mtDNA) in adipocytes. We sought to determine whether measurement of mtDNA in differing populations of peripheral blood also reveals depletion in patients treated with anti-retrovirals.
Methods: Twelve patients were selected who commenced triple therapy including stavudine as part of the INITIO study. Longitudinal samples of frozen buffy coats were selected from each patient prior to therapy, after 3 to 4 months on stavudine and then at 6-12 months of stavudine or 3 months after switching to zidovudine. Extraction of different cell populations was performed using dyna-beads that targeted specific cluster determinants CD19, CD8, CD4, CD14, CD15 and CD45. DNA was extracted from each cell population using minicolumns and measurement of mitochondrial DNA per cell was determined using real –time quantitative polymerase chain reaction.
Results: No significant change was detected in measures of mitochondrial DNA/cell in buffy coats taken after 3 to 4 months on stavudine compared with drug naive levels. Eight patients demonstrated a decrease in DNA copy number on therapy and of these 6 demonstrated a moderate, but not significant, increase in mitochondrial DNA after several months on the same (or switched) therapy. Interestingly, two patients showed marked increases in mtDNA in macrophages after 3 months on stavudine. Measurements of mitochondrial DNA did not reveal any significant correlation between time on therapy and mitochondrial DNA depletion in the total buffy coat or any of the cell populations examined.
Conclusion: The measurement of mitochondrial DNA copies/cell in peripheral blood cell populations did not detect significant mitochondrial DNA depletion after 3 to 12 months of HAART. Possible confounding factors may include differences in cell population kinetics, activation state and mitochondrial organelle mass.
|Publication Type:||Conference Paper|
|Murdoch Affiliation:||Centre for Clinical Immunology and Biomedical Statistics|
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