Patients infected with a particular subtype of HIV, the virus that causes AIDS, are more likely to develop dementia than patients with other subtypes, a study led by Johns Hopkins researchers shows.
The finding, reported in the September Clinical Infectious Diseases, is the first to demonstrate that the specific type of HIV has any effect on cognitive impairment, one of the most common complications of uncontrolled HIV infection.
HIV occurs in multiple forms, distinguished by small differences in the virus' genetic sequence and designated by letters A through K. Certain subtypes appear to cluster in particular areas of the world, and others have been associated with different rates of progression to full blown AIDS. Of the 35 million people living worldwide with HIV, the majority live in sub-Saharan Africa, where subtypes A, C and D dominate.
Nearly half of patients with advanced HIV infections have at least mild cognitive impairments, and about 5 percent have the severe form of cognitive impairment known as dementia.
In earlier research, Ned Sacktor, M.D., and his colleagues found that about 31 percent of patients visiting an infectious disease clinic in the Ugandan capital, Kampala, where subtypes A and D dominate, had dementia. The finding led him and his team to wonder whether patients with different subtypes had different rates of dementia.
Sacktor, professor of neurology at the Johns Hopkins University School of Medicine and a clinician at the Johns Hopkins Bayview Medical Center, and his colleagues studied 60 HIV-infected patients from a Kampala clinic. All of the subjects had been part of a different study testing the effect of anti-retroviral drugs on cognitive impairment, but had not begun taking the drugs. After determining each patient's HIV subtype, they performed a battery of neurological and cognitive tests to assess each patient's brain function.
As expected, the majority of the patients had HIV subtypes A or D. Out of the 33 subtype A patients, the researchers determined that seven had dementia, or about 24 percent. However, out of the nine patients with subtype D, 8 had dementia, about 89 percent.
"We were amazed to see such a dramatic difference in dementia frequencies between these two subtypes," Sacktor says. "If this is the case in all of sub-Saharan Africa, HIV-associated dementia may be one of the most common, but thus far unrecognized, dementias worldwide."
The research suggests that some biological property of each subtype seems to influence the likelihood that infected patients will develop dementia, says Sacktor. He and his team hypothesize that subtype D may cause more inflammation and injury in the brain, a possibility they are currently investigating.
For more information, go to:http://www.hopkinsmedicine.org/neurology_neurosurgery/experts/team_member
Christen Brownlee | EurekAlert!
New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia
New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences