IU Indianapolis ScholarWorks :: Browsing by Author "Brickman, Adam M."

Browsing by Author "Brickman, Adam M."

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A pathway linking pulse pressure to dementia in adults with Down syndrome
(Oxford University Press, 2024-05-09) Rizvi, Batool; Lao, Patrick J.; Sathishkumar, Mithra; Taylor, Lisa; Queder, Nazek; McMillan, Liv; Edwards, Natalie C.; Keator, David B.; Doran, Eric; Hom, Christy; Nguyen, Dana; Rosas, H. Diana; Lai, Florence; Schupf, Nicole; Gutierrez, Jose; Silverman, Wayne; Lott, Ira T.; Mapstone, Mark; Wilcock, Donna M.; Head, Elizabeth; Yassa, Michael A.; Brickman, Adam M.; Neurology, School of Medicine
Adults with Down syndrome are less likely to have hypertension than neurotypical adults. However, whether blood pressure measures are associated with brain health and clinical outcomes in this population has not been studied in detail. Here, we assessed whether pulse pressure is associated with markers of cerebrovascular disease and is linked to a diagnosis of dementia in adults with Down syndrome via structural imaging markers of cerebrovascular disease and atrophy. The study included participants with Down syndrome from the Alzheimer’s Disease - Down Syndrome study (n = 195, age = 50.6 ± 7.2 years, 44% women, 18% diagnosed with dementia). Higher pulse pressure was associated with greater global, parietal and occipital white matter hyperintensity volume but not with enlarged perivascular spaces, microbleeds or infarcts. Using a structural equation model, we found that pulse pressure was associated with greater white matter hyperintensity volume, which in turn was related to increased neurodegeneration, and subsequent dementia diagnosis. Pulse pressure is an important determinant of brain health and clinical outcomes in individuals with Down syndrome despite the low likelihood of frank hypertension.
Blood‐Based Biomarkers to Aid in Alzheimer’s Disease Prediction or Diagnosis: Analysis in a Multi‐Ethnic Cohort Study
(Wiley, 2025-01-03) Bahl, Aanya; Honig, Lawrence S.; Kang, Min Suk; Sanchez, Danurys; Reyes-Dumeyer, Dolly; Manly, Jennifer J.; Lantigua, Rafael A.; Dage, Jeffrey L.; Brickman, Adam M.; Vardarajan, Badri N.; Mayeux, Richard; Gu, Yian; Neurology, School of Medicine
Background: Blood‐based biomarkers may aid in the diagnosis of Alzheimer’s Disease (AD), but their contribution may be confounded by the presence of multiple chronic conditions and have not been well‐tested in community populations. In the current study, we aimed to determine whether blood‐based biomarkers can aid in refining a multi‐ethnic, urban clinically diagnosed AD community‐based cohort. Method: We included 546 individuals in the Washington Heights, Hamilton Heights, and Inwood Columbia Aging Project (WHICAP) study in this cross‐sectional study. Six biomarkers, including phosphorylated‐tau‐181 (P‐tau181), total (T‐tau), amyloid‐beta 40 and 42 (Aβ40, Aβ42), Glial Fibrillary Acid Protein (GFAP), and Neurofilament Light Chain (NfL) were measured using Quanterix SIMOA HD‐X platforms. The association between the biomarkers and AD or cognitive impairment was tested using logistic regression, adjusted for age, sex, ethnic group, and years of education. Individuals were subsequently characterized as ‘biomarker positive’ or ‘biomarker negative’ based on combined GFAP and P‐tau181/Aβ42 cut scores. Result: The mean age of individuals was 79.3 years (6.56) and 379 (69.4%) were women, 133 (24.48%), were Non‐Hispanic Black, 153 (28.0%) Non‐Hispanic White, and 248 (45.4%) were Hispanic. A clinical diagnosis of AD was made in 129 (25.49%) individuals. Low Aβ42 (OR = 0.18, [95% CI: 0.04 ‐ 0.92]), low Aβ42/Aβ40 (OR = 0.49, [95% CI: 0.228 ‐ 0.872), and high P‐tau181/Ab42 (OR = 5.494, [95% CI: 1.523 – 20.416]) were associated with a clinical diagnosis of AD suggesting a role as predictive biomarkers. However, the best combination, GFAP and P‐tau181/Aβ42 cut scores, yielded a sensitivity of 41% and specificity of 70.5% for clinically diagnosed AD. The concordance was 54.5% and the discordance was present in both directions. Low education, cardiovascular and other comorbidities might contribute to the discrepancy between biomarker positivity and clinical diagnosis. Conclusion: While GFAP and P‐tau181/Aβ42 levels are associated with AD pathology and can aid in the diagnosis of AD, the presence of multiple chronic conditions may lead to either false positives or negatives. Large multi‐ethnic community cohort studies are needed to further examine the utility of these biomarkers in aiding in the clinical diagnosis of AD.
Cerebrovascular disease drives Alzheimer plasma biomarker concentrations in adults with Down syndrome
(medRxiv, 2023-11-30) Edwards, Natalie C.; Lao, Patrick J.; Alshikho, Mohamad J.; Ericsson, Olivia M.; Rizvi, Batool; Petersen, Melissa E.; O’Bryant, Sid; Flores-Aguilar, Lisi; Simoes, Sabrina; Mapstone, Mark; Tudorascu, Dana L.; Janelidze, Shorena; Hansson, Oskar; Handen, Benjamin L.; Christian, Bradley T.; Lee, Joseph H.; Lai, Florence; Rosas, H. Diana; Zaman, Shahid; Lott, Ira T.; Yassa, Michael A.; Gutierrez, José; Wilcock, Donna M.; Head, Elizabeth; Brickman, Adam M.; Neurology, School of Medicine
Importance: By age 40 years over 90% of adults with Down syndrome (DS) have Alzheimer's disease (AD) pathology and most progress to dementia. Despite having few systemic vascular risk factors, individuals with DS have elevated cerebrovascular disease (CVD) markers that track with the clinical progression of AD, suggesting a role for CVD that is hypothesized to be mediated by inflammatory factors. Objective: To examine the pathways through which small vessel CVD contributes to AD-related pathophysiology and neurodegeneration in adults with DS. Design: Cross sectional analysis of neuroimaging, plasma, and clinical data. Setting: Participants were enrolled in Alzheimer's Biomarker Consortium - Down Syndrome (ABC-DS), a multisite study of AD in adults with DS. Participants: One hundred eighty-five participants (mean [SD] age=45.2 [9.3] years) with available MRI and plasma biomarker data were included. White matter hyperintensity (WMH) volumes were derived from T2-weighted FLAIR MRI scans and plasma biomarker concentrations of amyloid beta (Aβ42/Aβ40), phosphorylated tau (p-tau217), astrocytosis (glial fibrillary acidic protein, GFAP), and neurodegeneration (neurofilament light chain, NfL) were measured with ultrasensitive immunoassays. Main outcomes and measures: We examined the bivariate relationships of WMH, Aβ42/Aβ40, p-tau217, and GFAP with age-residualized NfL across AD diagnostic groups. A series of mediation and path analyses examined causal pathways linking WMH and AD pathophysiology to promote neurodegeneration in the total sample and groups stratified by clinical diagnosis. Results: There was a direct and indirect bidirectional effect through GFAP of WMH on p-tau217 concentration, which was associated with NfL concentration in the entire sample. Among cognitively stable participants, WMH was directly and indirectly, through GFAP, associated with p-tau217 concentration, and in those with MCI, there was a direct effect of WMH on p-tau217 and NfL concentrations. There were no associations of WMH with biomarker concentrations among those diagnosed with dementia. Conclusions and relevance: The findings suggest that among individuals with DS, CVD promotes neurodegeneration by increasing astrocytosis and tau pathophysiology in the presymptomatic phases of AD. This work joins an emerging literature that implicates CVD and its interface with neuroinflammation as a core pathological feature of AD in adults with DS.
Cerebrovascular disease emerges with age and Alzheimer's disease in adults with Down syndrome
(Springer Nature, 2024-05-29) Lao, Patrick; Edwards, Natalie; Flores‑Aguilar, Lisi; Alshikho, Mohamad; Rizvi, Batool; Tudorascu, Dana; Rosas, H. Diana; Yassa, Michael; Christian, Bradley T.; Mapstone, Mark; Handen, Benjamin; Zimmerman, Molly E.; Gutierrez, Jose; Wilcock, Donna; Head, Elizabeth; Brickman, Adam M.; Neurology, School of Medicine
Adults with Down syndrome have a genetic form of Alzheimer's disease (AD) and evidence of cerebrovascular disease across the AD continuum, despite few systemic vascular risk factors. The onset and progression of AD in Down syndrome is highly age-dependent, but it is unknown at what age cerebrovascular disease emerges and what factors influence its severity. In the Alzheimer's Biomarker Consortium-Down Syndrome study (ABC-DS; n = 242; age = 25-72), we estimated the age inflection point at which MRI-based white matter hyperintensities (WMH), enlarged perivascular spaces (PVS), microbleeds, and infarcts emerge in relation to demographic data, risk factors, amyloid and tau, and AD diagnosis. Enlarged PVS and infarcts appear to develop in the early 30s, while microbleeds, WMH, amyloid, and tau emerge in the mid to late 30s. Age-residualized WMH were higher in women, in individuals with dementia, and with lower body mass index. Participants with hypertension and APOE-ε4 had higher age-residualized PVS and microbleeds, respectively. Lifespan trajectories demonstrate a dramatic cerebrovascular profile in adults with Down syndrome that appears to evolve developmentally in parallel with AD pathophysiology approximately two decades prior to dementia symptoms.
Cerebrovascular disease is associated with Alzheimer's plasma biomarker concentrations in adults with Down syndrome
(Oxford University Press, 2024-09-25) Edwards, Natalie C.; Lao, Patrick J.; Alshikho, Mohamad J.; Ericsson, Olivia M.; Rizvi, Batool; Petersen, Melissa E.; O’Bryant, Sid; Flores Aguilar, Lisi; Simoes, Sabrina; Mapstone, Mark; Tudorascu, Dana L.; Janelidze, Shorena; Hansson, Oskar; Handen, Benjamin L.; Christian, Bradley T.; Lee, Joseph H.; Lai, Florence; Rosas, H. Diana; Zaman, Shahid; Lott, Ira T.; Yassa, Michael A.; Alzheimer’s Biomarkers Consortium–Down Syndrome (ABC-DS) Investigators; Gutierrez, José; Wilcock, Donna M.; Head, Elizabeth; Brickman, Adam M.; Neurology, School of Medicine
By age 40 years, over 90% of adults with Down syndrome have Alzheimer's disease pathology and most progress to dementia. Despite having few systemic vascular risk factors, individuals with Down syndrome have elevated cerebrovascular disease markers that track with the clinical progression of Alzheimer's disease, suggesting a role of cerebrovascular disease that is hypothesized to be mediated by inflammatory factors. This study examined the pathways through which small vessel cerebrovascular disease contributes to Alzheimer's disease-related pathophysiology and neurodegeneration in adults with Down syndrome. One hundred eighty-five participants from the Alzheimer's Biomarkers Consortium-Down Syndrome [mean (SD) age = 45.2 (9.3) years] with available MRI and plasma biomarker data were included in this study. White matter hyperintensity (WMH) volumes were derived from T2-weighted fluid-attenuated inversion recovery MRI scans, and plasma biomarker concentrations of amyloid beta 42/40, phosphorylated tau 217, astrocytosis (glial fibrillary acidic protein) and neurodegeneration (neurofilament light chain) were measured with ultrasensitive immunoassays. We examined the bivariate relationships of WMH, amyloid beta 42/40, phosphorylated tau 217 and glial fibrillary acidic protein with age-residualized neurofilament light chain across Alzheimer's disease diagnostic groups. A series of mediation and path analyses examined statistical pathways linking WMH and Alzheimer's disease pathophysiology to promote neurodegeneration in the total sample and groups stratified by clinical diagnosis. There was a direct and indirect bidirectional effect through the glial fibrillary acidic protein of WMH on phosphorylated tau 217 concentration, which was associated with neurofilament light chain concentration in the entire sample. Amongst cognitively stable participants, WMH was directly and indirectly, through glial fibrillary acidic protein, associated with phosphorylated tau 217 concentration, and in those with mild cognitive impairment, there was a direct effect of WMH on phosphorylated tau 217 and neurofilament light chain concentrations. There were no associations of WMH with biomarker concentrations among those diagnosed with dementia. The findings from this cross-sectional study suggest that among individuals with Down syndrome, cerebrovascular disease promotes neurodegeneration by increasing astrocytosis and tau pathophysiology in the presymptomatic phases of Alzheimer's disease, but future studies will need to confirm these associations with longitudinal data. This work joins an emerging literature that implicates cerebrovascular disease and its interface with neuroinflammation as a core pathological feature of Alzheimer's disease in adults with Down syndrome.
Comparing cortical signatures of atrophy between late-onset and autosomal dominant Alzheimer disease
(Elsevier, 2020) Dincer, Aylin; Gordon, Brian A.; Hari-Raj, Amrita; Keefe, Sarah J.; Flores, Shaney; McKay, Nicole S.; Paulick, Angela M.; Shady Lewis, Kristine E.; Feldman, Rebecca L.; Hornbeck, Russ C.; Allegri, Ricardo; Ances, Beau M.; Berman, Sarah B.; Brickman, Adam M.; Brooks, William S.; Cash, David M.; Chhatwal, Jasmeer P.; Farlow, Martin R.; la Fougère, Christian; Fox, Nick C.; Fulham, Michael J.; Jack, Clifford R., Jr.; Joseph-Mathurin, Nelly; Karch, Celeste M.; Lee, Athene; Levin, Johannes; Masters, Colin L.; McDade, Eric M.; Oh, Hwamee; Perrin, Richard J.; Raji, Cyrus; Salloway, Stephen P.; Schofield, Peter R.; Su, Yi; Villemagne, Victor L.; Wang, Qing; Weiner, Michael W.; Xiong, Chengjie; Yakushev, Igor; Morris, John C.; Bateman, Randall J.; Benzinger, Tammie L.S.; Neurology, School of Medicine
Defining a signature of cortical regions of interest preferentially affected by Alzheimer disease (AD) pathology may offer improved sensitivity to early AD compared to hippocampal volume or mesial temporal lobe alone. Since late-onset Alzheimer disease (LOAD) participants tend to have age-related comorbidities, the younger-onset age in autosomal dominant AD (ADAD) may provide a more idealized model of cortical thinning in AD. To test this, the goals of this study were to compare the degree of overlap between the ADAD and LOAD cortical thinning maps and to evaluate the ability of the ADAD cortical signature regions to predict early pathological changes in cognitively normal individuals. We defined and analyzed the LOAD cortical maps of cortical thickness in 588 participants from the Knight Alzheimer Disease Research Center (Knight ADRC) and the ADAD cortical maps in 269 participants from the Dominantly Inherited Alzheimer Network (DIAN) observational study. Both cohorts were divided into three groups: cognitively normal controls (nADRC = 381; nDIAN = 145), preclinical (nADRC = 153; nDIAN = 76), and cognitively impaired (nADRC = 54; nDIAN = 48). Both cohorts underwent clinical assessments, 3T MRI, and amyloid PET imaging with either 11C-Pittsburgh compound B or 18F-florbetapir. To generate cortical signature maps of cortical thickness, we performed a vertex-wise analysis between the cognitively normal controls and impaired groups within each cohort using six increasingly conservative statistical thresholds to determine significance. The optimal cortical map among the six statistical thresholds was determined from a receiver operating characteristic analysis testing the performance of each map in discriminating between the cognitively normal controls and preclinical groups. We then performed within-cohort and cross-cohort (e.g. ADAD maps evaluated in the Knight ADRC cohort) analyses to examine the sensitivity of the optimal cortical signature maps to the amyloid levels using only the cognitively normal individuals (cognitively normal controls and preclinical groups) in comparison to hippocampal volume. We found the optimal cortical signature maps were sensitive to early increases in amyloid for the asymptomatic individuals within their respective cohorts and were significant beyond the inclusion of hippocampus volume, but the cortical signature maps performed poorly when analyzing across cohorts. These results suggest the cortical signature maps are a useful MRI biomarker of early AD-related neurodegeneration in preclinical individuals and the pattern of decline differs between LOAD and ADAD.
Comparison of amyloid accumulation between Down syndrome and autosomal-dominant Alzheimer disease
(Wiley, 2022) Boerwinkle, Anna H.; Gordon, Brian A.; Wisch, Julie K.; Flores, Shaney; Henson, Rachel L.; Butt, Omar Hameed; Chen, Charles D.; Benzinger, Tammie L. S.; Fagan, Anne M.; Handen, Benjamin L.; Christian, Bradley T.; Head, Elizabeth; Mapstone, Mark; Klunk, William E.; Rafii, Michael S.; O’Bryant, Sid E.; Price, Julie C.; Schupf, Nicole; Laymon, Charles M.; Krinsky-McHale, Sharon J.; Lai, Florence; Rosas, H. Diana; Hartley, Sigan L.; Zaman, Shahid; Lott, Ira T.; Silverman, Wayne; Brickman, Adam M.; Lee, Joseph H.; Allegri, Ricardo Francisco; Berman, Sarah; Chhatwal, Jasmeer P.; Chui, Helena C.; Cruchaga, Carlos; Farlow, Martin R.; Fox, Nick C.; Goate, Alison; Day, Gregory S.; Graff-Radford, Neill R.; Jucker, Mathias; Lee, Jae-Hong; Levin, Johannes; Martins, Ralph N.; Mori, Hiroshi; Perrin, Richard J.; Salloway, Stephen P.; Sanchez-Valle, Raquel; Schofield, Peter R.; Xiong, Chengjie; Karch, Celeste M.; Hassenstab, Jason J.; McDade, Eric; Bateman, Randall J.; Ances, Beau M.; Neurology, School of Medicine
Background: Given the triplication of chromosome 21 and the location of the amyloid precursor protein gene on chromosome 21, almost all adults with Down syndrome (DS) develop Alzheimer disease (AD)-like pathology and dementia during their lifetime. Comparing amyloid accumulation in DS to autosomal dominant AD (ADAD), another genetic form of AD, may improve our understanding of early AD pathology development. Method: We assessed amyloid positron emission tomography (PET) imaging in 192 participants with DS and 33 sibling controls from the Alzheimer’s Biomarker Consortium-Down Syndrome (ABC-DS) and 265 mutation-carriers (MC) and 169 familial controls from the Dominantly Inherited Alzheimer Network (DIAN) (Table 1). We calculated regional standard uptake value ratios (SUVR) using a cerebellar cortex reference region and converted global amyloid burden SUVR to centiloids. We compared amyloid PET by cognitive status and estimated-years-to-symptom-onset (EYO). EYO was calculated for DIAN participants by subtracting their age from parental age of symptom onset and for ABC-DS participants by subtracting their age from 50.2 years, a published average age of symptom onset in a large sample of individuals with DS (Fortea et al., 2020). In a subset of participants, we assessed the relationship between amyloid PET and CSF Aβ42/40. Result: The relationship between CSF Aβ42/40 and amyloid PET was similar in DS and MC participants (Figure 1). We did not observe significant differences between MC and DS grouped by cognitive status (Figure 2). However, when assessed over EYO, global amyloid burden was significantly elevated in MC at EYO ≥ -23 but was not elevated in DS until EYO ≥ -15 (Figure 3). We observed early cortical and subcortical amyloid PET increases in both groups, but we also measured some regional differences in amyloid PET changes between MC and DS, specifically in the medial occipital region (Figure 4 and 5). Conclusion: These results demonstrate similarities in the relationship between amyloid biomarkers and the levels of amyloid accumulation in ADAD and DS. However, we also observed a 5-10 year delay and some regional differences in amyloid accumulation in DS. This is important for future clinical trials to consider when recruiting participants and determining treatment efficacy.
Correlation of plasma and neuroimaging biomarkers in Alzheimer’s disease
(Wiley, 2022) Brickman, Adam M.; Manly, Jennifer J.; Honig, Lawrence S.; Sanchez, Danurys; Reyes-Dumeyer, Dolly; Lantigua, Rafael A.; Vonsattel, Jean Paul; Teich, Andrew F.; Kang, Min Suk; Dage, Jeffrey L.; Mayeux, Richard; Neurology, School of Medicine
Blood-based phosphorylated tau (Ptau) 181 and 217 biomarkers are sensitive and specific for Alzheimer's disease. In this racial/ethnically diverse cohort study, participants were classified as biomarker positive (Ptau+) or negative (Ptau-) based on Ptau 181 and 217 concentrations and as cognitively impaired (Sym) or unimpaired (Asym). The four groups, Ptau-/Asym, Ptau+/Asym, Ptau-/Sym, and Ptau+/Sym, differed by age, APOE-4 allele frequency, total tau, neurofilament light chain, and cortical thickness measured by MRI. Our results add to increasing evidence that plasma Ptau 181 and 217 concentrations are valid Alzheimer's disease biomarkers in diverse populations.
Increased fibrin deposition in the brains of individuals with Down syndrome and Alzheimer’s disease
(Wiley, 2025-01-03) Du, Annie; Flores-Aguilar, Lisi; Edwards, Natalie C.; Lao, Patrick J.; Ryu, Jae Kyu; Akassoglou, Katerina; Wilcock, Donna M.; Kofler, Julia; Ikonomovic, Milos D.; Lai, Florence; Brickman, Adam M.; Head, Elizabeth; Neurology, School of Medicine
Background: Individuals with Down syndrome (DS) have an increased genetic risk of developing Alzheimer’s disease (AD), with most adults developing AD neuropathology in their 40s. Despite having a low frequency of systemic vascular risk factors such as hypertension and atherosclerosis, adults with DS display cerebrovascular pathology, including microbleeds, microinfarcts, and cerebral amyloid angiopathy. This suggests that blood‐brain barrier (BBB) integrity may be compromised allowing the extravasation of blood proteins in the brain parenchyma. The blood coagulation factor fibrin promotes immune‐mediated neurodegeneration and is a marker of BBB disruption in a wide range of neurological diseases. This study investigated the severity of fibrin deposition as a measure of BBB integrity in the brains of adults with DS and AD pathology (DSAD). We hypothesized that fibrin deposition is increased in DSAD in comparison to neurotypical controls without DS or AD. Method: Fibrin immunoreactivity was assessed by free‐floating immunohistochemistry in 30µm tissue sections from the occipital cortex from neurotypical controls (n = 12; 41‐65 years old) and DSAD (n = 12; 46‐66 years old). Using whole slide imaging, brain sections were digitized, and the severity of fibrin deposition was scored using Aperio Imagescope. Result: Individuals with DSAD display significantly higher fibrin deposition in the white and grey matter of the occipital cortex in comparison to the age‐matched neurotypical controls (p<0.0001). Conclusion: Neurotypical controls display minimal fibrin deposition in the brain parenchyma and perivascular space. However, compared to neurotypical controls, adults with DS at advanced stages of AD neuropathology display significant fibrin deposition in the occipital cortex, suggesting that the BBB may be compromised in this population.
Independent and interactive contributions of cerebrovascular disease, neuroinflammation, and tau pathophysiology to Alzheimer’s disease‐related diagnostic conversion in adults with Down syndrome
(Wiley, 2025-01-09) Edwards, Natalie C.; Lao, Patrick J.; Alshikho, Mohamad J.; Rizvi, Batool; Flores Aguilar, Lisi; Petersen, Melissa; O’Bryant, Sid E.; Tudorascu, Dana; Handen, Benjamin L.; Gutierrez, Jose; Wilcock, Donna M.; Head, Elizabeth; Brickman, Adam M.; Neurology, School of Medicine
Background: By age 40 years, adults with Down syndrome (DS) develop Alzheimer’s disease (AD) pathology and progress to dementia in their 60s. Despite minimal systemic vascular risk factors, individuals with DS have MRI evidence of cerebrovascular injury that progresses with AD severity, suggesting an intrinsic vascular component to DS‐AD that may interact with neuroinflammatory processes to promote tau pathology and cognitive decline. In the current study we examined whether cerebrovascular disease (CVD) burden and inflammation/astrocytosis independently and interactively were associated with incident diagnosis among adults with DS. Method: This study included 149 participants from the Alzheimer Biomarkers Consortium – Down Syndrome (baseline mean age[SD]=44.6[9] years) with available baseline MRI, plasma biomarker data, and at least two time‐points of clinical consensus diagnosis data (i.e., cognitively stable, mild cognitive impairment [MCI], and clinical AD) who were classified as cognitively stable or MCI at baseline. Logistic regression models assessed if baseline small vessel CVD, operationalized as white matter hyperintensity (WMH) volume, and plasma glial fibrillary acidic protein (GFAP), Aβ42/Aβ40, p‐tau217, and neurofilament light (NfL) concentrations are associated with conversion from a milder diagnosis to a more severe clinical diagnosis. Mediation models examined relationships between biomarkers and diagnostic conversion. All models adjusted for study site, sex/gender, latency between visit dates, and age group (below or above/equal to the median age of the sample). Result: Diagnostic conversion occurred in 26% of the sample. Higher baseline WMH volume (OR 1.08 [1.01, 1.81]), GFAP (OR 1.006 [1.003, 1.01]), and p‐tau217 (OR 20.56 [5.01, 112.43]), but not NfL nor Aβ42/Aβ40 concentrations were associated with higher odds of conversion to more severe cognitive impairment. GFAP concentration mediated the relationship between WMH and diagnostic conversion (ACME 0.05 [0.01, 0.1], p=0.006). P‐tau217 concentration mediated the relationship between GFAP and diagnostic conversion (ACME 0.13 [0.05, 0.23], p=0.004). Conclusion: Our findings suggest that among individuals with DS, CVD promotes AD‐related clinical progression by increasing astrocytosis which, in turn, promotes tau pathophysiology and downstream MCI and AD incidence. The results implicate CVD and its interface with inflammation as a core feature of AD in DS.

Browsing by Author "Brickman, Adam M."

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