Performance of the plasma Aβ42/Aβ40 ratio, measured with a novel HPLC-MS/MS method, as a biomarker of amyloid PET status in a DPUK-KOREAN cohort

Table 2 Performance of plasma Aβ42/Aβ40 to predict PET positivity and concordance with PET

	*AUC* (unadjusted)	*AUC* (adjusted)	Concordant/total cases^a (concordance rate)	Discordant cases^a
	*AUC* (unadjusted)	*AUC* (adjusted)	Concordant/total cases^a (concordance rate)	Plasma+/PET−	Plasma−/PET+
Total	0.814	0.920^b	384/503 (76.3%)	60 (11.9%)	59 (11.7%)
OC	0.826	0.890^c	114/148 (77.0%)	29 (19.6%)	5 (3.4%)
aMCI	0.815	0.872^c	158/210 (75.2%)	23 (11.0%)	29 (13.8%)
ADD	0.812	0.877^c	99/130 (72.7%)	6 (4.6%)	25 (19.2%)
YC	NA	NA	13/15 (86.7%)	2 (13.3%)	NA

PET positron emission tomography; ADD Alzheimer’s disease dementia; aMCI amnestic mild cognitive impairment; OC old controls; YC young controls; AUC area under the receiver operating characteristic curve
^aThis concordance classification was based on the plasma Aβ42/Aβ40 ratio of 0.2576 obtained from the total group
^bLogistic analysis after adjusting for age, APOE4 status, and diagnosis
^cLogistic analysis after adjusting for age and APOE4 status

ISSN: 1758-9193