Mitochondrial DNA depletion in adipose tissue of HIV-infected patients with peripheral lipoatrophy.

BACKGROUND

NRTI-induced host toxicity is proposed to involve cellular mitochondrial DNA (mtDNA) depletion. Determinants of cellular mtDNA copy number from HIV-infected patients receiving HAART and HIV-seronegative controls were investigated from subcutaneous fat samples, and relation with antiretroviral regimen was studied.

STUDY DESIGN

HIV-infected patients receiving HAART (n = 50), HIV-infected patients not currently under HAART regimen (n = 2) and HIV-seronegative controls (n = 9) of similar age and BMI were enrolled prospectively when undergoing Coleman's lipostructure for correction of facial lipoatrophy or plastic surgery, respectively. After centrifugation, abdominal fat tissue was collected and stored at -80 degrees C. MtDNA analysis was blindly performed after a total DNA extraction from adipose tissue, followed by a real-time PCR quantification. The log of mtDNA copies/cell in adipose tissue [log(DNA)] was compared between groups by means of analysis of variance.

RESULTS

The log(DNA) in adipose tissue of HIV-infected patients was significantly lower than in the HIV-seronegative control group (P < 0.0001). In HIV-infected patients, log(DNA) was significantly reduced in the 50 NRTI-treated patients (P < 0.01), but not when considering mtDNA level according to the use of PI or NNRTI in current HAART regimen. In NRTI-treated patients, only stavudine (n = 20) and didanosine (n=14) were significantly and independently associated with reduced mtDNA level (P < 0.0001 and <0.05, respectively). Currently stavudine or didanosine-treated patients had a significant reduced mtDNA level compared to past users (P < 0.0001 and <0.05, respectively). Other clinical, biological, and immuno-virological variables than NRTI did not correlate significantly to adipocyte mtDNA level.

CONCLUSION

This study supports that current treatment by NRTI is a main determinant of mtDNA depletion in adipose tissue of HIV-seropositive patients with peripheral fat wasting. Stavudine or didanosine current intake is significantly associated with mtDNA depletion in vivo, that could be reversible after the discontinuation of these molecules, when considering mtDNA level according to current use versus past use of these molecules.