This Week in HIV Research: Future Gene Therapy Target; HIV-Associated Neurocognitive Disorders; and Treating Hodgkin Lymphoma
This week, we read about a newly identified part of a protein that helps fight HIV and could provide a target for future gene therapy. We also see new data on the prevalence of HIV-associated neurocognitive disorders. And another study finds that HIV-positive African Americans living with Hodgkin lymphoma are less likely to be on chemotherapy than their white counterparts. To beat HIV, you have to follow the science!
Researchers in the U.S. and Canada have identified part of a protein that helps to thwart HIV, giving a potential new target for gene therapy development, according to a study published in the journal Heliyon.
The protein, known as TRIM5alpha, is present in all primates, such as humans, and has the ability to inhibit HIV and other viruses. TRIM5alpha can also switch on the immune system to help fight off HIV, which the researchers believe it does by attaching to another protein known as SUMO.
In this study, the researchers identified a new part of TRIM5alpha that could attach to SUMO, thereby switching on the immune system. This newly identified part is called SIM4, short for "SUMO interacting motif 4."
By mutating SIM4, the TRIM5alpha protein was no longer able to inhibit HIV, suggesting SIM4 plays a key role in arming TRIM5alpha, the researchers found. Finding a way to safely manipulate this process should be an aim for future gene therapy.
"Our cells can mount a surprisingly complex response to viral infections," said corresponding author Lionel Berthoux, Ph.D., according to the study press release. "Finding a way to tweak the activity of these antiviral factors so that they target HIV, or other viruses of interest, is a valuable avenue of research."
For people living with HIV, the prevalence of HIV-associated neurocognitive disorders (HAND) is common. However, for those on treatment with a sustained undetectable viral load, HAND is not a progressive condition over four years of follow-up, according to a study published in the journal Neurology.
The study analyzed data for 364 HIV-positive individuals from the Multicenter AIDS Cohort Study (MACS) between 2007 and 2012. Overall, the frequency of HAND increased from 2009-2010 to 2011-2012 (P = 0.048).
For the 197 participants who were seen during all time periods, the frequency was 25% during 2007-2008, 25% during 2009-2010, and 31% during 2011-2012. About 77% of these individuals remained at the same HAND stage over the study, while 13% showed deterioration and 10% improved.
Having high cholesterol was associated with HAND progression. Being diagnosed with an asymptomatic neurocognitive impairment was associated with double the risk of symptomatic HAND when compared with normal cognition.
For HIV-positive individuals living with Hodgkin lymphoma, those who are African American are significantly less likely to receive cancer treatment than their white counterparts, according to a study published in the journal AIDS.
"Black patients have higher rates of not receiving treatment," said lead author Adam Olszewski, M.D. in the study press release. "Hodgkin lymphoma is generally believed to be highly curable. We have an expectation to cure over 90% of early-stage patients and even 70-80% of quite advanced cases."
The study analyzed data on 2,090 HIV-positive individuals with Hodgkin lymphoma from between 2004 and 2012. The researchers found that older age, being male, nonwhite race, and poor socioeconomic status were associated with higher risk of not being on chemotherapy.
Specifically, after adjusting for confounding factors, black HIV-positive patients were 67% less likely to be on chemotherapy than white HIV-positive patients.
These findings are particularly alarming considering that in 2012, 49% of HIV-positive individuals living with Hodgkin lymphoma were black and 15% were Hispanic. "The disparity in treatment delivery needs attention because a majority of HIV-positive Americans with Hodgkin lymphoma are now black or Hispanic, and this proportion is increasing," the researchers concluded.