Type of AIDS Infection Key to Death Risk -- Study

The clade, or subtype, of HIV infection was a better predictor of rapid AIDS mortality than viral load in a Ugandan study recently presented at the 13th Conference on Retroviruses and Opportunistic Infections in Denver. Conducted by US and Ugandan researchers, the study found that people infected with clade D HIV died more quickly than those infected with clade A virus.

HIV has mutated into nine clades that roughly correspond to geographical boundaries. Clades A and D are found in Uganda, while clade C is common in Botswana, South Africa, India and parts of China. Clade B is prevalent in Europe and the United States.

Researchers studied 300 men and women newly infected with HIV between 1995 and 2001 in Rakai, Uganda. Of those infected, 53 had clade A HIV, 203 had clade D, and 70 were infected with a mixed A-D clade.

Of those infected with clade D virus, 10 percent died within three years, and none of those with clade A died so quickly, the study found. People with clade A lived an average 8.8 years, compared to just 6.9 years for people with clade D virus and 5.8 years for those with A-D clade.

"Knowing a person's HIV subtype is important for the management of the infection because the disease can progress more rapidly in those infected with subtype D ... than in those with other subtypes," said Olivier Laeyendecker, a senior research associate with Johns Hopkins University (JHU) School of Medicine who led the investigation. For those HIV patients with medical care, DNA testing to determine clade may be an important aspect of that care, researchers said.

The JHU team said clade D may be more virulent because 25 percent of D virus uses multiple receptors, CCR5 and CXCR4, to infect T cells while clade A uses just CCR5. Of those whose virus used CXCR4, two-thirds died within three years, said researchers.

Back to other news for February 13, 2006