AIDS experts at Johns Hopkins say they have compelling evidence that some people with HIV who for years and even decades show extremely low levels of the virus in their blood never progress to full-blown AIDS and remain symptom free even without treatment, probably do so because of the strength of their immune systems, not any defects in the strain of HIV that infected them in the first place.
Their conclusions about so-called elite suppressors, published this month in the Journal of Virology, come from rigorous blood and genetic studies from a monogamous, married, African-American couple in Baltimore, in which the wife was infected through sex with her husband more than a decade ago.
Unlike her husband, the wife remains symptom free, has consistently had viral counts of fewer than 50 copies per cubic milliliter of blood, and has not needed any treatment to keep the disease in check. The husband, as a so-called progressor, takes a potent drug cocktail to keep his infection from developing into full-blown AIDS, as demonstrated by viral counts in the hundreds of thousands per cubic milliliter of blood. The couple has been married for two decades and the husband was an intravenous drug user.
The scientists say the case study disproves some suspect theories about elite suppression that suggest it always involves a defective or "weakened" viral strain, which is easier for the immune system to attack, or that genetic variants confer a protective effect in suppressors.
"This is an extremely rare case of co-infection in a controlled, monogamous relationship, which showed us how a strong immune system in the elite suppressor kept the virus from replicating and infecting other cells," says senior study investigator and infectious disease specialist Joel Blankson, M.D., Ph.D.
"Our findings offer hope to vaccine researchers because they reveal that the immune system's primary offense, known as CD8 killer T-cells,
|Contact: David March|
Johns Hopkins Medical Institutions