Drug resistance testing in PBMCs of HIV infected patients

HIV infected patients are considered a sort of reservoir having different g enetically distinct viral variants((2-6)) (quasispecies), that evolve from the starting virus inoculum. Frequently, during replication, HIV can genera te nucleotide differences in the new viral population; such genetic changes may be uninfluential in viral "fitness" (replication capacity) or give the virus some advantages under a selective pressure, due to immune response o r drug treatment. The use of potent combination therapy for the treatment o f HIV infections has certainly improved the "quality of life" for patients, decreasing the viral load in the plasma (HIV RNA). In our study, we invest igated whether detection of drug resistance-related mutations was possible in circulating PBMCs, which represent a sort of genetic archive of viral dr ug resistances, when the levels of viral RNA were reduced to below 400 or 5 0 copies/ml, since, generally, plasma samples with more than 1,000 copies/m l of HIV RNA are needed to generate some results. The study was successfull y performed sequencing proviral HIV DNA in PBMCs from 32 samples belonging to 25 patients, using a new modified protocol, that showed a good reproduci blity and very interesting data, also in patients with low or without circu lating HIV RNA levels.