Analysis of NRTI-associated resistance mutations of the HIV-genome in mothers and infants after antiretroviral prophylaxis consisting of AZT, 3TC and NVP

In a cohort of about 150 Tanzanian mother-infant pairs, it is being investigated if NRTI-associated resistance mutations are emerging in addition to NNRTI-associated resistance mutations. It is also being assessed if using a triple combination prophylaxis regimen can impede resistance formation. Special emphasis is given to pre-delivery resistance formation and the possibility of mother-to-child transmission of virus strains resistant to therapy.

Moreover, long-term AZT intake is being analyzed regarding impairment of maternal or infant mitochondria. Allele-specific real time PCR (ASPCR), a method established at the Institute of Tropical Medicine Berlin, is being extended with regards to NRTI-associated mutations in the frame of this research project. Apart from establishing further assays for ASPCR, "Ultra Deep Sequencing" for HIV subtypes A and D is being established in cooperation with Robert-Koch-Institut Berlin. To examine multi-resistance in viruses, i.e. viruses showing NNRTI- and NRTI-mutations on the same gene segment, all samples with a NRTI or NNRTI mutation are being analyzed using mutation-specific amplicon sequencing. To find out about possible mitochondrial impairment after AZT intake, the absolute amount of mitochondrial DNA as well as the amount of a specific 4977bp deletion of mtDNA in blood, placenta and umbilical cord samples is being determined. Those analyses are being conducted in cooperation with the Department of Forensic Genetics of the Institute of Forensic Medicine, University of Kiel.