YKL-40 was quantified in the plasma of 315 cases, including healthy controls (HC), neurological disease controls (ND), AD, vascular dementia (VaD), frontotemporal dementia (FTD), sporadic Creutzfeldt-Jakob disease (CJD) and Lewy body dementia (LBD).
The diagnostic and classificatory performances of all combinations of three core (amyloid β peptide [i.e., Aβ<sub>1-42</sub>], total tau [t-tau], and phosphorylated tau) and three novel (neurofilament light chain protein, neurogranin, and YKL-40) cerebrospinal fluid biomarkers of neurodegeneration were compared among individuals with mild cognitive impairment (n = 41), Alzheimer's disease dementia (ADD; n = 35), frontotemporal dementia (FTD; n = 9), and cognitively healthy controls (HC; n = 21), using 10-fold cross-validation.
Level II: YKL-40 discriminated tau-positive individuals and AD pathophysiology-positive individuals from HC, AD pathophysiology-positive patients from FTD (AUROCs = 0.76, 0.72, 0.73).