Diagnostic value of cerebrospinal fluid Aβ ratios in preclinical Alzheimer’s disease

Table 2 Diagnostic performance of different CSF analytes with ¹⁸F-flutemetamol PET as autopsy-validated standard of truth (EUROIMMUN assay)

	AUC	SE	95 % CI	Cutoff^a	Sensitivity (%)	Specificity (%)	Correctly classified^b (%)
Aβ38	0.571	0.111	0.401–0.730	2909	100	32.26	45
Aβ40	0.571	0.112	0.401–0.730	10738	100	29.03	42
Aβ42*†	0.908	0.051	0.769–0.977	745	100	74.19	79
ttau	0.724	0.148	0.555–0.856	436	71.43	80.65	76
Aβ42/Aβ38*	0.935	0.039	0.806–0.989	0.332	100	87.10	89
Aβ42/Aβ40*†	0.954	0.033	0.832–0.995	0.096	100	80.65	84
Aβ42/ttau*†	0.963	0.028	0.846–0.998	2.006	100	87.10	89

Analyte concentrations are described as pg/ml or calculated as ratios between concentrations of two analytes
Statistically significant differences of AUCs between analytes: *P _corrected < 0.05 compared with Aβ40; †P _corrected < 0.05 compared with Aβ38. No other differences of AUCs were found
^aCutoff value corresponding to the highest Youden index
^bPercentage of positively classified cases based on the CSF cutoff compared with amyloid PET classification
Aβ amyloid beta, AUC area under the receiver operating characteristic curve, CI confidence interval, CSF cerebrospinal fluid, PET positron emission tomography, SE standard error, ttau total tau

ISSN: 1758-9193