P4‐291: Identification and validation of a blood‐based transcriptomic signature (AclarusDx) in the diagnosis of Alzheimer's disease

Biomarkers have gained an increased importance in the past years in helping physicians to diagnose AD. In addition to usual methods such as brain imaging and CSF, recent data have shown that peripheral blood may be a potential source for AD-related biomarker identification. The objective was to identify a blood-based transcriptomic signature (AclarusDx) by comparing 90 AD patients to 87 asymptomatic control subjects. The performance of the signature was then evaluated in a final independent blinded population of 164 individuals (91 AD and 73 controls)after removal of samples within the grey zone boundaries. The AclarusDx signature consists of 170 probesets which map to 136 genes. A significant number of them are associated with inflammatory pathways and are independent of pathways involved in amyloid or tau metabolism. The AclarusDx performance on this validation cohort had a sensitivity of 81.32% (95% CI : [73.31%; 89.33%] and a specificity of 67.12% (95%CI : [56.34%; 77.89 %]). AclarusDx is a non-invasive blood-based transcriptomic test that may provide physicians with objective information supporting AD diagnosis process, in association with other standard assessments.