Elecsys CSF biomarker immunoassays demonstrate concordance with amyloid-PET imaging

Table 2 ROC curve results—CSF biomarkers for prediction of Aβ-PET status

Biomarker	AUC (95% CI)	Threshold	Optimisation method	PPA (%)	NPA (%)	OPA (%)
Aβ42	0.86 (0.81–0.92)	1054 pg/mL	Youden	81	81	81
tTau	0.81 (0.75–0.87)	213 pg/mL	Youden	86	66	75
pTau	0.84 (0.78–0.89)	21.3 pg/mL	Youden	81	77	79
Aβ42/Aβ40	0.94 (0.89–0.98)	0.064	Youden	90	90	90
Aβ42/Aβ40	0.94 (0.89–0.98)	0.0673	GMM	92	88	90
tTau/Aβ42	0.94 (0.90–0.98)	0.258	Youden	83	97	91
tTau/Aβ42	0.94 (0.90–0.98)	0.165	GMM	92	80	85
pTau/Aβ42	0.94 (0.90–0.98)	0.0183	Youden	90	91	91
pTau/Aβ42	0.94 (0.90–0.98)	0.0159	GMM	90	83	86

Abbreviations: Aβ, β-amyloid; Aβ42, β-amyloid (1–42); Aβ42/Aβ40, β-amyloid (1–42)/β-amyloid (1–40) ratio; AUC, area under the curve; CI, confidence interval; CSF, cerebrospinal fluid; GMM, Gaussian mixture model; NPA, negative percentage agreement; OPA, overall percentage agreement; PET, positron emission tomography; PPA, positive percentage agreement; pTau, phosphorylated tau (181P); pTau/Aβ42, phosphorylated tau (181P)/β-amyloid (1–42) ratio; ROC, receiver operating characteristic; tTau, total tau; tTau/Aβ42, total tau/β-amyloid (1–42) ratio

ISSN: 1758-9193