Genetic factors influencing HIV infection: a review

Patient’s genetic background, especially in the HLA and CCR5 regions, strongly influences outcomes of HIV-1 infection. Understanding how host genetic factors can contribute to disease progression can help guide intervention strategies. To date, it has been estimated that HLA and CCR5 loci account for around 13% of variations in viremia set point. However, a key question in understanding all complex phenotypes, including HIV-1 progression, is what degree of influence different genetic variants can have. Presence of a 32bp deletion in CCR5 gene is associated with slower progression of HIV infection and positive effect on survival among cART untreated patients. Some studies have assessed CCR5-Δ32 as the most potent protective variant, both in immunological and viremic context, unrelated to HLA. Variants of CCR2 (rs1799864) are associated with slower progression to AIDS. CX3CR1 variant (rs3732378) may limit the shift in HIV-1 tropism from R5 to X4. This polymorphism may influence both disease progression and HIV tropism. HLA-C -35 (rs9264942) C/C variant is associated with a significant reduction in HIV viral load compared to T/T homozygote. Moreover, HLA-B*5701 has been confirmed to be more common in patients with slow disease progression to AIDS. Patient’s genetic background, especially in HLA and CCR5 regions, strongly influences the progression of HIV-1 infection as well as viremic and immunologic values