The PRESTIGIO Registry (NCT04098315) is an observational, prospective, Italian, multicenter, annual collection of biological samples (plasma and peripheral blood mononucleated cells; PBMCs) and data on clinical, laboratory, treatment, and virological characteristics of PWLH harboring a 4-drug-class-resistant virus (4DCR).

Registry is active since December 2017.
Currently, the PRESTIGIO Registry includes 39 infectious diseases hospital centers, located throughout Italy.
Up to now, 233 PLWH with a 4 DCR HIV were included in the PRESTIGIO Registry.

The registry includes people with the following characteristics: age >18 years; a documented resistance to the 4 classes of antiretroviral drugs (NRTIs, NNRTIs, PIs, INSTIs), defined as intermediate or high-level resistance to at least 1 drug of each class according to the Stanford algorithm [https://hivdb.stanford.edu/]; if no INSTI genotypic resistance test is available, a documented virological failure to an INSTI-regimen (at least 2 consecutive HIV-RNA values > 50 copies/mL) was accepted as an inclusion criterion.

• Multicentric National Registry.
• Active Since December 2017.
• Dedicated to People infected with multiresistant HIV.