Rates of amyloid PET positivity in geriatric HIV: Neuroimaging / differential diagnosis. (7th December 2020)

• Record Type: Journal Article
• Authors: Milanini, Benedetta; Javandel, Shireen; Hillis, Madeline; Chen, Karen; Hellmuth, Joanna; Paul, Robert; Pohl, Kilian M; Valcour, Victor
• Is Part Of: Alzheimer's & dementia. Volume 16(2020)Supplement 5
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-07
• Subjects: Alzheimer's disease -- Periodicals; Alzheimer Disease -- Periodicals; Dementia -- Periodicals; Démence; Maladie d'Alzheimer; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.83
• DOI: 10.1002/alz.044134
• Languages: English
• ISSNs: 1552-5260

Abstract

Abstract: Background: Chronic HIV infection and amyloid deposition with aging may represent a double‐hit to the brain. We aimed to define the rate of amyloid positivity among older HIV‐infected adults and contrast the demographic, clinical and neuropsychological features of HIV+ amyloid PET+ individuals compared to HIV+ amyloid PET‐ participants. Method: Study sample included 52 adults with chronic HIV infection. Participants underwent a standardized neurological and neuropsychological assessment that tapped multiple cognitive domains. HIV diagnostic criteria informed by clinical acumen were applied to diagnose HIV‐associated neurocognitive disorder. None of the participants showed a clinical picture consistent with Alzheimer's disease (AD). Florbetapir amyloid PET scans were read by trained and certified neurologists as positive (n=5) or negative (n=47) (Johnson et al., 2013). T‐tests and chi‐squared tests were performed to explore differences between the two groups. Result: We found 10% rate of amyloid positivity in our cohort. The PET‐ and PET+ groups were similar in age, sex and education. The mean (SD; range) age was 67 (5; 60‐86) for PET‐ and 69 (5; 63‐73) for PET+ participants. All participants but two were male (PET‐: 45 (96%); PET+: 5 (100%)). The mean (SD) education was 16 (2) for both groups. No differences were found in clinical HIV‐related variables. For PET‐ participants, mean (SD) nadir and current CD4 count were 165 (126) and 574 (275) versus 188 (116) and 620 (180) in the PET+ group. All participants were on antiretroviral treatment with undetectable HIV RNA in plasma. Cognitively, all participants presented with mild neurocognitive disorder and the two groups performed similarly in all the cognitive domains explored, including memory. Conclusion: Results reveal a low frequency of amyloid positivity among virally suppressed HIV‐infected individuals over the age of 60, similar to that published among the age‐matched seronegative population (i.e., 12%), suggesting that HIV does not link to a higher amyloid plaque burden. Moreover, older HIV‐infected individuals classified as amyloid positive exhibit a similar profile as their amyloid negative counterparts. While we did not observe an increased amyloid deposition by using PET, further studies are needed to determine if amyloid PET is an effective tool for identifying AD in the setting of HIV.