Host Genetic Susceptibility
The Centers for Disease Control and Prevention (CDC) has released findings that genes influence susceptibility to HIV infection and progression to AIDS. HIV enters cells through an interaction with both CD4 and a chemokine receptor of the 7 transmembrane family. They first reviewed the role of genes in encoding chemokine receptors (CCR5 and CCR2) and chemokines (SDF-1). While CCR5 has multiple variants in its coding region, the deletion of a 32-bp segment results in a nonfunctional receptor, thus preventing HIV entry; two copies of this gene provide strong protection against HIV infection, although the protection is not absolute. This allele is found in around 10% of Europeans but is rare in Africans and Asians. Multiple studies of HIV-infected persons have shown that presence of one copy of this mutation, named CCR5-Δ32 (CCR5 delta 32) delays progression to the condition of AIDS by about 2 years.
The National Institute of Health (NIH) has funded research studies to learn more about this genetic mutation. In such research, NIH has found that there exist genetic tests that can determine if a person has this mutation. Implications of a genetic test may in the future allow clinicians to change treatment for the HIV infection according to the genetic makeup of an individual, Currently there exist several at-home tests for the CCR5 mutation in individuals; however, they are not diagnostic tests.
A relatively new class of drugs for HIV treatment relies on the genetic makeup of the individual. Entry inhibitors bind to the CCR5 protein to block HIV from binding to the CD4 cell.
Read more about this topic: HIV Disease Progression Rates
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