Hello, all. My areas of research are memory and neurodegeneration, and I am not very well versed in the HIV-related dementia/HAND literature. So, if there is someone here reading this that is, I would be grateful for some feedback.
Basically, we have some data showing a strong correlation between a (relatively) novel memory measure we have been developing (recency ratio) and CD4 count, thus suggesting this memory measure is sensitive to infection levels. Of note, this is independent on general cognitive ability (MMSE) and was measured in a relatively young population. Also, CD4 does not appear to be correlated significantly with other measures of memory in this sample, including immediate recency (which has been reported in several papers before as a typical sign of cogntive impairment in HIV).
My question is: Is this finding of interest beyond simply reporting another cognitive correlate of decline in HIV? Is there any utility in this cognitive marker for screening and/or clinical assessment?
Thanks,
Davide
These are studies in which computerized cognitive assessment has been used to determine cognitive impairement in HIV,
1. The assessment of cognitive function in advanced HIV-1 infection and ...
www.sciencedirect.com/science/article/pii/S0887617705001629
2.Evaluation of brief screening tools for neurocognitive impairment in HIV/AIDS: a systematic review of the literature
Amy R. Zipursky et al AIDS. 2013 Sep 24; 27(15): 2385–2401.
Recent publications estimate the prevalence of human immunodeficiency virus (HIV)–associated neurocognitive disorders (HAND) exceeds 50%, and this rate is likely higher among older patients. Cognitive impairment may impact medication adherence, and symptomatic impairment has been linked to all-cause mortality providing some impetus for early detection. There are currently insufficient data to inform solid recommendations on screening methods however this is a review article on the subject matter
Screening for Cognitive Impairment in Human Immunodeficiency Virus
Victor Valcour et al., Clin Infect Dis. (2011) 53 (8): 836-842. doi: 10.1093/cid/cir524
Hi Davide,
Your results sound really interesting! I'm not familiar with the HIV literature either, but the correlation you identified between CD4+ cells and memory reminds me of some of the work Jonathan Kipnis' lab does. They've examined the effect of T cells and other leukocytes on cognitive performance in mice using SCID and TCR restricted models among others. I'm not sure if its helpful, but they published a review article in 2008 comparing immune contributions to HIV-dementia and age related dementia.
https://www.ncbi.nlm.nih.gov/pubmed/18789764
I hope it helps!
Andrew
https://www.ncbi.nlm.nih.gov/pubmed/18789764
Dear Andrew,
Thanks a lot! I am going to have a look at that.
All the best,
Davide
HIV is associated with difficulties in many cognitive domains, including short term memory which eventually gets consolidated into long term memory and learning.
A full screen for cognitive functions is essential for all HIV patients, especially those that can expose themselves or others to harm from cognitive impairment.
There is definitely a correlation between HIV infection and cognitive decline.Concerning the use of your findings in the development of cognitive markers; I think it may hold some promise.
Dear Muktar and Olakunle,
Thanks both for your feedback. Best wishes of a great 2017!
Davide
OK. If this measure somehow addresses an early change not already addresses by other measures, a specific change that predicts disease process, or provides a simpler measure of cognitive state or disease process than those currently in use, then the measure has the potential for clinical utility.
The MMSE is such a gross measure of impairment that there are many memory alterations in HIV that do not correlate with changes in the MMSE. Pretty much, by the time a patient is showing changes in the MMSE, a wide range of processes are impaired, including but not limited to memory. It would be interesting to see what more specific related cognitive processes were spared or affected in individuals with recency ratio alterations. What is the nature of the correlation, ie is it logarithmic? It the correlation limited to CD4? Does it predict anything, or is it predicted by anything? Is this a very early marker of the onset of cognitive impairment?
Thanks for your feedback, Lynn. If we go ahead with this, then all those answers will be addressed in our paper.
Even though the clinical utility is unclear (now) that would be very interesting. The other problem with HIV studies is that the damage is subtle and dispersed. I found that frustrating as I could not physically identify a specific area of damage underlying the cognitive change[s]. It would be supercool if you could identify the physical mechanism in subsequent studies. Enjoy the work!