Is plasma amyloid-β 1–42/1–40 a better biomarker for Alzheimer’s disease than AβX–42/X–40?

Table 1 Characteristics of the study cohort

	All (n = 73)^a	Aβ⁻ (n = 37)^b	Aβ⁺ (n = 36)^b	P-value^c
Age [mean ± SD]	69.3 ± 7.8	67.1 ± 7.8	71.6 ± 7.2	0.0126
Female	42 (57.5%)	20 (54.1%)	22 (61.1%)
Male	31 (42.5%)	17 (45.9%)	14 (38.9%)
ApoE4 carrier	35 (47.9%)	8 (21.6%)	27 (75%)
CSF AβX–42/X–40 [mean ± SD]	0.058 ± 0.025	0.082 ± 0.0055	0.033 ± 0.0056	< 0.0001
CSF AβX–42 [pg/mL, mean ± SD]	380.8 ± 217.8	530.0 ± 198.4	227.4 ± 96.7	< 0.0001
CSF AβX–40 [pg/mL, mean ± SD]	6678.2 ± 2598.4	6377.3 ± 2132.2	6987.4 ± 3003.2	0.5067
CSF t-Tau CSF [pg/mL, mean ± SD]^d	417.5 ± 344.6	225.6 ± 80.2	614.8 ± 398.5	< 0.0001
CSF pTau181 [pg/mL, mean ± SD]^{d, e}	60.0 ± 33.7	39.5 ± 11.3	81.0 ± 36.0	< 0.0001

Aβ amyloid-β
^aFive subjects (out of originally 78) were excluded from the statistical analysis resulting in a final sample size of n = 73
^bThe clinical sample was dichotomized according to the AβX–42/X–40 ratio in cerebrospinal fluid (CSF) measured with the MSD Aβ panel 1 (6E10) V-PLEX multiplex assay
^cTwo-tailed Mann–Whitney test p-values for the comparison between the groups amyloid-negative (Aβ⁻, CSF AβX–42/X–40 > 0.058, n = 37) and amyloid-positive (Aβ⁺, CSF AβX–42/X–40 ≤ 0.058, n = 36)
^dCSF levels of total Tau (t-Tau) and phospho-Tau-181 (pTau181) were routinely determined in a clinical laboratory
^eFor one subject, the measured pTau181 concentration was < 15.6 pg/mL. For the statistical analysis, this value was artificially set to a fixed value of 15.6 pg/mL

ISSN: 2045-8118