Genetic Variation Associated With Survival Advantage in African American...( WASHINGTON July 20 -- Fr...),Health

WASHINGTON, July 20 /PRNewswire-USNewswire/ -- From the start of the HIV epidemic, it appeared that some of the people who were infected with the virus were able to ward off the fatal effects of the disease longer than others. Recent studies have begun to unravel the cause of this phenomenon, and new research suggests that African Americans with the disease have a unique survival advantage if they have both a low white blood cell count (known as leukopenia) and a genetic variation that is found mainly in persons of African ancestry. This study was prepublished online on July 20, 2009, in Blood, the official journal of the American Society of Hematology.

The research showed that African Americans with HIV who possess both a variation in the gene for the Duffy antigen receptor for chemokine (DARC) and leukopenia have slower HIV-to-AIDS progression rates than HIV-infected European Americans with leukopenia. Previous studies showed that the same DARC variant conferred protection for persons of African ancestry against a particular form of malaria, and that persons of African descent have, on average, lower white blood cell (WBC) counts than persons of European ancestry. Leukopenia is one of several blood conditions observed frequently in patients with HIV-1 infection, but its impact on disease course is relatively unknown.

"Even though leukopenia is tied to both African ancestry and faster disease progression, we found that compared with European Americans, African American patients with HIV who have leukopenia do not necessarily experience this expected outcome," said lead author Sunil Ahuja, MD, of the Veterans Administration (VA) Research Center for AIDS and HIV-1 Infection and the University of Texas Health Science Center in San Antonio.

This study evaluated data from the Air Force subset of the U.S. Military's HIV Natural History Study and included genetic and cli
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