Quantification of SNAP-25 with mass spectrometry and Simoa: a method comparison in Alzheimer’s disease

Table 2 Receiver operating characteristic analysis and fold change results for the CSF SNAP-25 analysis on the two platforms

		CU− vs CU+	CI− vs CI+	CU− vs CI+	CU− vs CI−
SNAP-25 [Simoa]	*ROC*
	AUC (CI⁷)	0.79 (0.60–0.99)	0.74 (0.57–0.90)	0.82 (0.70–0.94)	0.54 (0.29–0.80)
	p-value	0.0147*	0.0182*	0.0006***	0.6063
	*Fold change*
	Mean (Std)	1.42 (0.51)	1.39 (0.45)	1.57 (0.51)	1.1 (0.49)
SNAP-25 [Long] IP-MS	*ROC*
	AUC (CI)	0.64^a (0.41–0.87)	0.70 (0.52–0.88)	0.77 (0.64–0.91)	0.54 (0.30–0.78)
	p-value	0.2441	0.0448*	0.0034**	0.7327
	*Fold change*
	Mean (Std)	1.44 (0.76)	1.48 (0.73)	1.93 (0.94)	1.24 (0.81)
SNAP-25 [Total] IP-MS	*ROC*
	AUC (CI)	0.71 (0.49–0.93)	0.61^a (0.41–0.82)	0.69^a (0.53–0.85)	0.53 (0.28–0.79)
	p-value	0.0855	0.2621	0.0441*	0.7697
	*Fold change*
	Mean (Std)	1.29 (0.47)	1.21 (0.47)	1.43 (0.55)	1.15 (0.61)

Notes: The DeLong test was used to statistically compare AUC values head-to-head. Kruskal-Wallis with post hoc Dunn’s test and false discovery rate (FDR) correction for multiple comparisons using the two-stage step-up method of Benjamini, Krieger, and Yekutieli (Q = 0.05) was used to compare fold changes in the same diagnostic groups between the biomarkers (no significance found). The level of significance used was p ≤ 0.05. ^aSignificant DeLong test compared to SNAP-25 Simoa (p ≤ 0.05)
Abbreviations: CU− cognitively unimpaired Aβ negative, CU+ cognitively unimpaired Aβ positive, CI− cognitively impaired Aβ negative, CI+ cognitively impaired Aβ positive, ROC receiver operating characteristic, AUC area under the curve, CI confidence interval, Std standard deviation

ISSN: 1758-9193