Proteomic profiles for Alzheimer's disease and mild cognitive impairment among adults with Down syndrome spanning serum and plasma: An Alzheimer's Biomarker Consortium-Down Syndrome (ABC-DS) study

Introduction:Previously generated serum and plasma proteomic profiles were examined among adults with Down syndrome (DS) to determine whether these profiles could discriminate those with mild cognitive impairment (MCI-DS) and Alzheimer's disease (DS-AD) from those cognitively stable (CS). Methods:Data were analyzed on n=305 (n=225 CS; n=44 MCI-DS; n=36 DS-AD) enrolled in the Alzheimer's Biomarker Consortium-Down Syndrome (ABC-DS). Results:Distinguishing MCI-DS from CS, the serum profile produced an area under the curve (AUC)=0.95 (sensitivity [SN]=0.91; specificity [SP]=0.99) and an AUC=0.98 (SN=0.96; SP=0.97) for plasma when using an optimized cut-off score. Distinguishing DS-AD from CS, the serum profile produced an AUC=0.93 (SN=0.81; SP=0.99) and an AUC=0.95 (SN=0.86; SP=1.0) for plasma when using an optimized cut-off score. AUC remained unchanged to slightly improved when age and sex were included. Eotaxin3, interleukin (IL)-10, C-reactive protein, IL-18, serum amyloid A , and FABP3 correlated fractions at r2>=0.90. Discussion:Proteomic profiles showed excellent detection accuracy for MCI-DS and DS-AD.