Objective
Evaluate blood mitochondrial DNA (mtDNA) content in HIV/antiretroviral (ARV)-exposed uninfected (HEU) vs. HIV-unexposed uninfected (HUU) infants and investigate differences in mitochondrial-related metabolites by exposure group.
Design
We enrolled a prospective cohort of HIV-infected and -uninfected pregnant woman/infant pairs in Cameroon.
Methods
Dried blood spot mtDNA:nuclear DNA ratio was measured by monochrome multiplex qPCR in HEU infants exposed to in utero ARVs and postnatal zidovudine (HEU-Z) or nevirapine (HEU-N), and in HUU infants at 6 weeks of life. Acylcarnitines (ACs) and branch-chain amino acids (BCAAs) were measured via tandem mass spectrometry and consolidated into 7 uncorrelated components using principal component analysis (PCA). Linear regression models were fit to assess the association between in utero/postnatal HIV/antiretroviral exposure and infant mtDNA, adjusting for confounders and PCA-derived AC/BCAA component scores.
Results
Of 364 singleton infants, 38 were HEU-Z, 117 HEU-N, and 209 HUU. Mean mtDNA content was lowest in HEU-Z infants (140 vs. 160 in HEU-N vs. 174 in HUU, p=0.004). After adjusting for confounders, HEU-Z infants remained at increased risk for lower mtDNA content compared to HUU infants (β: −4.46, p=0.045), while HEU-N infants did not, compared to HUU infants (β: −1.68, p=0.269. Furthermore, long-chain ACs were associated with lower (β:−2.35, p=0.002) and short-chain and BCAA-related ACs were associated with higher (β:2.96, p=0.001) mtDNA content.
Conclusion
Compared to HUU infants, HEU infants receiving postnatal zidovudine appear to be at increased risk for decreased blood mtDNA content which may be associated with altered mitochondrial fuel utilization in HEU-Z infants.