Biomarker profiles in a memory clinic population according to new Alzheimer diagnostic framework: Biomarkers (non‐neuroimaging) / Multi‐modal comparisons.

Background: Different research diagnostic criteria and frameworks for Alzheimer's disease have recently been proposed, but their applicability in clinical settings is unclear. This cross‐sectional study aimed at classifying biomarker profiles of memory clinic patients according to the ATN scheme and assessing patient characteristics in each category. Method: 284 consecutive patients from the Karolinska University Hospital, Theme aging, memory clinic with available CSF, MRI and clinical data were included (50% diagnosed with SCI, 24% with MCI, 26% with dementia). ATN classification was based on CSF β‐amyloid42 (A), CSF phosphorylated tau (T), and medial temporal atrophy (N), and clinical cut‐offs were used to determine biomarker positivity. When available, automated ratings of medial temporal lobe atrophy were used in the classification. Comparisons between the ATN categories were conducted with Kruskal‐Wallis and chi‐square tests. Result: The most frequent biomarker profile was A‐T‐N‐ (49% of the whole study population). 36% had a SNAP profile (A‐T+N‐, A‐T‐N+ or A‐T+N+) and 15% had any Alzheimer profile, i.e. abnormal amyloid (A+T‐N‐, A+T+N‐, A+T‐N+ or A+T+N+). Proportion of A+T+N+ patients increased with the severity of symptoms (0% in SCI and MCI, 22% in dementia), whereas the opposite was observed for A‐T‐N‐ patients (72% in SCI, 39% in MCI, 14% in dementia). Some biomarker profiles (A+T‐N‐, A+T‐N+, A+T+N‐) were underrepresented in the whole sample and in all diagnostic groups. Compared to normal biomarker profile, patients with an Alzheimer profile were older and more often APOE4 carriers, had a poorer cognitive performance (MoCa, MMSE, memory, attention), and had fewer depressive symptoms. Except for age and depressive symptoms, same differences were observed between SNAP and normal biomarker profile categories. There were no differences in white matter hyperintensities or education level between the profile categories. Conclusion: Proportion of patients with either a normal or SNAP biomarker profile was high in this memory clinic‐based study. Many of the proposed ATN categories were also not relevant in this patient population. Follow‐up studies are needed to assess cognitive decline and disease progression in the different ATN categories. [ABSTRACT FROM AUTHOR]