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) | 0.64a (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) | 0.61a (0.41–0.82) | 0.69a (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