JHM LogoPatients infected with a particular subtype of HIV seem to be more susceptible in developing dementia in contrast to patients with other subtypes. A subtype of HIV is known to be a virus which causes AIDS. Atleast this is what the researchers from Johns Hopkins have to say.

This research is the foremost one to have demonstrated that the specific type of HIV appears to have an effect on cognitive impairment. Apparently, it is one of the most common complications of uncontrolled HIV infection.

HIV is believed to take place in multiple forms which is distinguished by small differences in the virus’ genetic sequence and selected by letters A through K. Certain subtypes appear to gather in specific areas of the world, and others have been associated with different rates of progression to full blown AIDS.

It was estimated that out of the 35 million people living across the world with HIV, the majority exist in sub-Saharan Africa. In this sub-Saharan African the subtypes A, C and D seem to dominate.

It was noted that approximately half of the patients with higher HIV infections have at least mild cognitive impairments and nearly 5 percent appear to have dementia. This condition is known to be the severe form of cognitive impairment.

In a previous research, Ned Sacktor, M.D., along with his colleagues found that about 31 percent of patients appear to have been visiting an infectious disease clinic in the Ugandan capital, Kampala, where subtypes A and D dominate and that they suffered from dementia. This finding led him and his team to wonder whether patients with different subtypes could possibly have different rates of dementia.

For the purpose of better understanding this criterion, Ned Sacktor, professor of neurology at the Johns Hopkins University School of Medicine and a clinician at the Johns Hopkins Bayview Medical Center, along with his colleagues examined approximately 60 HIV-infected patients from a Kampala clinic.

All of the subjects were observed to have been part of a different study which was testing the effect of anti-retroviral drugs on cognitive impairment, however had not begun taking the drugs. During the examination, researchers found out each patient’s HIV subtype and then performed a series of neurological and cognitive tests in order to evaluate each patient’s brain function.

The findings revealed that majority of the patients seem to have HIV subtypes A or D. Supposedly, out of the 33 subtype A patients, researchers discovered that seven had dementia i.e. approximately 24 percent. However, out of the nine patients with subtype D, 8 seem to have dementia i.e. nearly 89 percent.

Sacktor stated that, “We were amazed to see such a dramatic difference in dementia frequencies between these two subtypes. 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.”

Researchers claimed that some biological property of each subtype appears to influence the probability that infected patients may perhaps develop dementia. They also put forward that subtype D could cause more inflammation and injury inside the brain. However, they appear to be currently examining this possibility.

The findings of the research will be published in the journal, Clinical Infectious Diseases.