Quantification of mitochondrial toxicity in HIV-infected individuals by quantitative PCR compared to flow cytometry
Thor A Wagner1, Chen-Han Lin, Nicole H Tobin
1Seattle Children's Research Institute, Seattle, Washington 98101, USA. agner@seattlechildrens.org
Background:
Non-invasive diagnostic assays to evaluate mitochondrial toxicity could have significant clinical utility for HIV-infected individuals on antiretroviral therapy (ART).
Methods:
This study compared the ratio of mitochondrial to nuclear DNA determined by quantitative polymerase chain reaction (qPCR) to the ratio of mitochondrial to nuclear-encoded proteins by flow cytometry, in peripheral blood mononuclear cells from 73 HIV-infected individuals with and without risk factors for mitochondrial toxicity.
Results:
PCR detected similar mitochondrial/nuclear DNA in HIV-infected individuals without a history of ART, and those receiving ART with lipodystrophy, lipoatrophy, or a history of suspected lactic acidosis. However, the ratio was significantly greater in ART-untreated compared to those receiving either stavudine or didanosine. In contrast, flow cytometry did not detect any differences in mitochondrial/nuclear protein (Lin et al., Cytometry B 2009;76B:181-190). There was no correlation between the assays (rho = -0.05, P = 0.65).
Conclusions:
Assessment of the mitochondrial/nuclear DNA ratio by qPCR performed better than the mitochondrial/nuclear-encoded protein ratio by flow cytometry to detect adverse effects of nucleoside analogs on mitochondria.
