Plasma Amyloid-β Oligomerization Tendency Predicts Amyloid PET Positivity

Figures & data

Figure 1 Concentration of plasma MDS-OAβ according to groups.

Abbreviations: AD, Alzheimer’s disease; MCI, mild cognitive impairment; MDS-OAβ, Multimer Detection System-Oligomeric Amyloid-β; OND, other neurodegenerative disease; SCD, subjective cognitive decline.

Table 1 Demographics and Clinical Characteristics of Subjects

	Amyloid-Negative (n=28)	Amyloid-Positive (n=68)	p-value
Age, years	74.00 (70.50–79.00)	70.00 (61.00–75.50)	0.058
Male, n (%)	13 (46.43)	29 (42.65)	0.910
Education, years	16.00 (12.00–16.00)	16.00 (12.00–16.00)	0.783
APOE ε4 carrier, n (%)	9 (36.0)	32 (55.17)	0.173
Diagnosis			<0.001
AD/MCI/SCD/OND*, n	4/11/6/7	50/16/1/1
MMSE	24.00 (20.00–26.00)	19.00 (11.00–25.00)	0.016
CDR	0.5 (0.5–0.75)	1.0 (0.5–1.0)	0.003
CDR-SOB	3.0 (2.0–4.25)	6.0 (2.0–8.0)	0.014
MDS-OAβ, ng/mL	0.67 ± 0.21	0.89 ± 0.17	<0.001

Notes: * OND includes FTD, PSP, PDD, and CBS. Data are presented as the median (interquartile range) or mean ± standard deviation unless otherwise specified.

Abbreviations: AD, Alzheimer’s disease; CBS, corticobasal syndrome; CDR, Clinical Dementia Rating; CDR-SOB, Clinical Dementia Rating Sum of Boxes; FTD, frontotemporal dementia; MCI, mild cognitive impairment; MMSE, Mini-Mental-State-Examination; MDS-OAβ, Multimer Detection System-Oligomeric Amyloid-β; OND, other neurodegenerative disease; PDD, Parkinson’s disease dementia; PSP, progressive supranuclear palsy; SCD, subjective cognitive decline.

Table 2 Performance of Predictors for Amyloid PET Positivity with and without MDS-OAβ Positivity

Predictors	AUC (95% CI)	Sensitivity (%)	Specificity (%)
MMSE	0.657 (0.545–0.769)	54.4	82.1
Age + MMSE	0.681 (0.572–0.789)	47.1	89.3
Age + APOE ε4	0.684 (0.552–0.816)	77.6	60.0
Age + APOE ε4 + MMSE	0.740 (0.626–0.853)	56.9	84.0
MDS-OAβ positivity	0.855 (0.776–0.933)	85.3	85.7
MMSE + MDS-OAβ positivity	0.892 (0.820–0.963)	86.8	85.7
Age + MMSE + MDS-OAβ positivity	0.922 (0.863–0.981)	91.2	82.1
Age + APOE ε4 + MDS-OAβ positivity	0.912 (0.844–0.980)	74.1	96.0
Age + APOE ε4 + MMSE + MDS-OAβ positivity	0.926 (0.871–0.980)	74.1	96.0

Abbreviations: AUC, area under the curve; CI, confidential interval; MMSE, Mini-Mental-State-Examination; MDS-OAβ, Multimer Detection System-Oligomeric Amyloid-β.

Figure 2 Receiver operating characteristic analysis of MDS-OAβ positivity with other predictors on amyloid PET positivity. (A) Added MDS-OAβ positivity to clinical information such as age, MMSE score, and APOE ε4 status, predictability for amyloid PET positivity improves. (B) Considered only objective factors such as age and APOE ε4 status, combining with MDS-OAβ positivity strengthened the predictability on amyloid PET positivity.

Abbreviations: MDS-OAβ, Multimer Detection System-Oligomeric Amyloid-β; MMSE, Mini-Mental-State-Examination.