Extended Data Fig. 2: Sensitivity analyses testing the association of Aβ PET and plasma GFAP according to other summary measures of TSPO PET.
From: Microglia modulate Aβ-dependent astrocyte reactivity in Alzheimer’s disease
Scatter plots displaying the association between global Aβ PET burden and plasma GFAP levels according to MATSPO status, with error bands representing the 95% CI of regression lines (left). Continuous associations between global Aβ PET, TSPO PET, and plasma GFAP (right). (a) TSPO PET SUVR estimated from a composite brain region that includes the areas showing higher TSPO PET SUVR (T-value > 2) in AD Aβ+ compared to CU Aβ- (caudal anterior cingulate, entorhinal, fusiform, inferior temporal, isthmus cingulate, lateral orbitofrontal, lingual, medial orbitofrontal, middle temporal, paracentral, parahippocampal, pars opercularis, pars orbitalis, pars triangularis, pericalcarine, posterior cingulate, precuneus, rostral middle frontal, superior frontal; Extended Data Fig. 10). (b) TSPO PET SUVR estimated from a composite brain region that includes the areas within the top decile for absolute TSPO PET SUVR differences between AD Aβ+ and CU Aβ- individuals (paracentral, pars triangularis, posterior cingulate, and precuneus; Extended Data Fig. 10). The thresholds used to define MA+TSPO were calculated using the corresponding composite brain region. β-estimates and corresponding two-sided P-values were computed from linear regression models with standardized biomarker levels, adjusted for age, sex, and cognitive status. The interaction models also accounted for the main effects of the interaction terms. For regressions in MA+TSPO, exact P-values are (a) 2.47 × 10−6 and (b) 2.16 × 10−4. Abbreviations: AD = Alzheimer’s disease; Aβ = amyloid-β; CI = confidence interval; CU = cognitively unimpaired; GFAP = glial fibrillary acidic protein; MA = microglial activation; PET = positron emission tomography; SUVR = standardized uptake value ratio; TSPO = translocator protein.
