Aβ₄₂ correlation with sphingomyelinase activity and ROC curves.

<p>Plots of Aβ₄₂ levels in CSF versus aSMase activity indicating the linear regression line with 95% confidence interval (dotted line) for CN (6A), MCI (6B), and AD (6C). Spearman r analyses indicate a significant positive correlation between Aβ₄₂ and aSMase in CN (<i>P < 0</i>.<i>01</i>) but not for MCI (<i>P >0</i>.<i>99</i>) or AD (<i>P > 0</i>.<i>39</i>). Linear regression analyses show that the slope is significantly non-zero for CN (<i>P < 0</i>.<i>01</i>) but not for MCI (<i>P > 0</i>.<i>16</i>) and AD (<i>P > 0</i>.<i>72</i>). An aSMase activity cutoff value of 20 RFU/min is shown for CN, MCI and AD.