ART ensures survival doesn’t depend on genetic lottery, Pg11

Key Highlights:

• Pre-antiretroviral therapy (ART), HLA-B alleles influenced HIV survival and transmission rates.
• Protective HLA-B alleles increased survival, while susceptible alleles accelerated illness.
• A study in South Africa indicated natural selection could have increased protective gene frequency by 38% over 45 years without intervention.
• ART has significantly slowed this genetic shift, diminishing the impact of HLA-B genes on survival.

Detailed Insights:

• Before ART, individuals with beneficial HLA-B alleles experienced prolonged survival and reduced mother-to-child HIV transmission.
• Conversely, those with disease-susceptible HLA-B alleles faced accelerated disease progression.
• The South African study highlights how natural selection favored protective HLA-B genes in the absence of medical intervention.
• ART's widespread use has altered the selective pressure on HLA-B alleles, reducing the genetic advantage conferred by specific genes.
• This shift ensures that survival is less dependent on an individual's genetic makeup and more on access to treatment.

Scientific/Technical Concepts Involved:

• Alleles: Different forms of a gene that arise by mutation and are found at the same place on a chromosome.
• Antiretroviral Therapy (ART): Treatment that uses medications to manage and control HIV by suppressing the virus.
• HLA-B Genes: Genes that play a role in the immune system and disease susceptibility, particularly in the context of HIV.