Rare HLA Types Slow AIDS Progression

Researchers studying HIV, the virus that causes AIDS, have found that HIV adapts to the most frequent human leukocyte antigen (HLA) proteins in a population, providing a selective advantage for patients with rare HLA proteins.

Investigators at the Los Alamos National Laboratory (New Mexico, USA) and Northwestern University (Evanston, IL, USA) studied a large group of homosexual men who were enrolled in the Chicago component of the Multicenter AIDS Cohort Study, an ongoing study of the natural and treated history of thousands of men infected with HIV. The extent of HIV infection, or disease progression, for each participant was determined by measuring the number of T-lymphocytes: the fewer the number of T-cells, the greater the level of HIV infection. The HLA profile of each participant was also determined.

Results of the study, which was published in the July 2003 issue of Nature Medicine, showed that those with common HLA types displayed the most severe HIV infections. Participants with rarer HLA types had less severe infections that took longer to develop.

The authors suggested that HIV adapts to the most frequent HLA types in the population, providing a selective advantage for those individuals who express rare forms.





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Los Alamos National Laboratory
Northwestern University