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Background:  Peripheral blood mononuclear cells (PBMC) mtDNA levels have been suggested as surrogate markers for NRTI-mediated mitochondrial toxicity including lipoatrophy. Utilizing samples from a previously reported lipoatrophy study, we report matched mtDNA copies/cell results from peripheral adipose tissues and PBMC devoid of platelets as assayed by real-time PCR. Our hypothesis is that PBMC devoid of platelets are a poor surrogate markers for HIV-lipoatrophy. To address this issue, PBMC and peripheral adipose tissues mtDNA copies/cell were quantitated in HIV-seropositive patients treated with nucleoside reverse transcriptase inhibitors (NRTI)-containing HAART with lipoatrophy for > 6 months, HIV-infected patients treated with NRTI-containing HAART with no lipoatrophy, HIV-infected patients naïve to antiretroviral therapy, and HIV seronegative participants.  

Methods:  The 4 cohort cross-sectional patient sample numbers varied from n = 3 to 10, see results below. PBMC were isolated by Ficoll gradient and the removal of platelets was confirmed by flow cytometry. Thigh, abdomen, and neck subcutaneous fat was obtained from all patients. Total DNA was isolated and integrity examined by agarose gel electrophoresis. Intact DNA was assayed for mtDNA copies/cell by real-time PCR using primers for the mitochondrial NADH dehydrogenase 2 and the nuclear Fas gene. Statistical analysis was done using the Mann-Whitney Rank Sum test for non-parametric data with the threshold for significance set at p = 0.05.

Results: MtDNA copies/cell for subcutaneous thigh, abdomen, neck adipose tissue and PBMCs are shown below. Data are expressed as mean ±SD. Groups with the superscript “a” are statistically significant from the HIV^- and HIV⁺ naïve. The HIV⁺ non-lipoatrophic abdomen mtDNA copies/cell with the “b” superscript is statistically significant with only the HIV^-.

Conclusions:  HIV lipoatrophy is associated with mitochondrial DNA depletion in different subcutaneous fat depots as measured by real-time PCR. PBMC mtDNA copies/cell did not correlate with lipoatrophy.

Keywords: Mitochondria; Lipoatrophy; DNA