Fig. 2
Bar plot illustrating the probability of αSyn SAA positivity stratified by amyloid status and clinical syndrome severity. Statistical significance was determined via logistic regression controlling for age (A). Scatterplot illustrating the interaction effect between amyloid-PET and αSyn SAA status on cross-sectional levels of CSF p-tau181/Aβ1 − 40 as an indicator of earliest tau pathophysiology. Diagnostic groups are indicated by shape, the cut-point of amyloid-PET positivity is indicated by the dashed red line at 25 centiloids. The beta value indicates the strength of the amyloid-PET x CSF αSyn SAA interaction effect as determined by linear regression, controlling for age, sex and study site. FDR-correction for multiple comparisons (p < 0.05) was applied for the main analyses (B), adjusting for five statistical tests