A protein that is one of the major predictors of Alzheimer’s disease also predicts the pace at which HIV-infected persons will progress to death, a team of U.S. scientists reported this week.

Researchers from The University of Texas Health Science Center at San Antonio, along with colleagues in Maryland and California, said the new study provides more conclusive evidence of a link for the protein, called apoE4, to infectious diseases, namely HIV.

The report is in this week’s online Proceedings of the National Academy of Sciences. The research team studied a population of 1,300 European and African-American HIV-infected patients. The scientists compared HIV clinical outcomes of individuals who have two copies of the gene that makes the apoE4 protein with outcomes of those endowed with two copies of a gene that makes a related protein, apoE3. The latter differs from apoE4 by a single amino acid.

They found the subjects with two copies of apoE4 were more likely to have a twofold faster HIV disease course, noticeably marked by progression to death, than subjects with two copies that make apoE3.

“The prevailing view is that apoE4 plays a role only in non-infectious diseases such as  Alzheimer’s disease , but we found clear evidence to the contrary,” said study co-author Sunil K. Ahuja, M.D., professor of medicine, microbiology, immunology and biochemistry at the UT Health Science Center and director of the Veterans Administration Research Center for AIDS and HIV-1 Infection in the South Texas Veterans Health Care System.

“These findings are very exciting because there are major efforts under way to find small molecules that make apoE4 more like apoE3,” said Hemant Kulkarni, M.D., a co-author from the UT Health Science Center.

“Such therapies might have application not only in  Alzheimer’s disease but also HIV disease,” said Matthew Dolan, M.D., a co-author from Wilford Hall Medical Center in San Antonio and a long-term collaborator of Dr. Ahuja.

Paper co-authors are Dr. Ahuja, Dr. Kulkarni, and Weijing He, M.D.; of the Health Science Center, and Dr. Dolan; Brian Agan, M.D.; and Vincent Marconi, M.D., of Wilford Hall Medical Center and the Infectious Diseases Clinical Research Program of the Uniformed Services University of the Health Sciences, Bethesda, Md. They performed the research with colleagues Robert W. Mahley, M.D., Ph.D., of the Gladstone Institutes in San Francisco, and Trevor Burt, M.D., and Joseph M. McCune, M.D., Ph.D., of the University of California, San Francisco.