Eveline C Timmermans | PubMed Health

PubMed2006

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.

BACKGROUND: To study the clinical relevance of changes in mitochondrial DNA (mtDNA) in peripheral blood mononuclear cells (PBMCs) attributable to HIV infection and/or combination antiretroviral therapy (cART), a high-throughput molecular assay to quantify mtDNA is required. METHODS: We developed a quantitative real-time duplex nucleic acid sequence-based amplification assay in which both mtDNA and nuclear DNA are simultaneously amplified in 1 tube. The assay could accurately quantify mtDNA in a range of 15-1500 copies of mtDNA per 2 genomic copies with an intrarun variation of 11% and an interrun variation of 16%. We compared this real-time assay with the lactate/pyruvate ratios in fibroblasts incubated with glucose and exposed to zalcitabine. Additionally, we studied the effects of platelet contamination and the in vivo effects of cART on mtDNA in PBMCs from a small group of patients. RESULTS: Decreases in mtDNA preceded the increase in lactate/pyruvate ratios and vice versa when zalcitabine was eliminated from the culture. Platelets affected the mtDNA in PBMCs if >5 platelets per PBMC were present. Within 12 weeks, mtDNA increased and remained increased in PBMCs from patients on continuous treatment with zidovudine/lamivudine/indinavir therapy (P = 0.03), but increased if patients were switched to stavudine/didanosine therapy (P = 0.008). CONCLUSION: After drug exposure, the mtDNA assay can detect changes in mtDNA concentrations in cell lines and PBMCs, when properly controlled for platelet effects, earlier than traditional assays.

Anti-HIV Agents↗

PubMed2005

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.

BACKGROUND: Mitochondrial DNA (mtDNA) in peripheral blood mononuclear cells (PBMCs) has been suggested as a potential marker of mitochondrial toxicity associated with nucleoside analogue reverse-transcriptase inhibitor-containing therapy. METHODS: We quantified mtDNA and mitochondrial RNA (mtRNA) in PBMCs over the course of 48 weeks in 78 patients infected with human immunodeficiency virus type 1 (HIV-1) who were randomly assigned to receive ritonavir-boosted indinavir and efavirenz with or without stavudine. Furthermore, we analyzed the association of mtDNA and mtRNA with clinical signs and symptoms and/or abnormalities in laboratory markers attributed to mitochondrial toxicity. RESULTS: No statistically significant difference was found in mtDNA and mtRNA content over time between the 2 treatment arms. When arms were combined, both median mtDNA and mtRNA content showed statistically significant increases over the course of 48 weeks, from 206 to 278 copies/cell (P < .001) and from 154 to 288 copies/cell (P = .003), respectively. No statistically significant difference in mtDNA and mtRNA content was found between patients with and those without adverse events attributed to mitochondrial toxicity. CONCLUSIONS: The observed increases in mtDNA and mtRNA content during the first year of treatment may represent a restorative trend resulting from suppression of HIV-1 infection, independent of the treatment used. Future studies should focus on well-defined mitochondrial toxicities and changes in these markers within the corresponding affected tissues simultaneously with those in PBMCs. Furthermore, with respect to studies of peripheral blood, mtDNA and mtRNA content in individual cell subtypes rather than in PBMCs may be better markers of toxicity and deserve further investigation.

Adult↗