Fig. 4

Binding of serum IgM to non-pTau peptide in NCI, MCI, and AD subjects. Means (circle), medians (line through center of box), upper and lower quartiles (upper and lower borders of box, respectively), most extreme non-outlier values (lines extending from box), and outliers (asterisks) are shown for non-pTau IgM ratios in serum samples from NCI, MCI, and AD subjects. “non-pTau IgM ratio” is the ratio of a serum sample’s IgM binding to non-phosphorylated tau peptide-coated wells divided by its IgM binding \( \mathrm{to}\ \mathrm{BSA}\hbox{-} \mathrm{coated}\ \mathrm{wells}:\frac{\mathrm{OD}\ \mathrm{for}\ \mathrm{IgM}\ \mathrm{binding}\ \mathrm{to}\ \mathrm{non}\hbox{-} \mathrm{pTau}\ \mathrm{peptide}}{\mathrm{OD}\ \mathrm{for}\ \mathrm{IgM}\ \mathrm{binding}\ \mathrm{to}\ \mathrm{BSA}} \) The between-group differences did not achieve statistical significance (p = 0.26). (NCI = no cognitive impairment; MCI = mild cognitive impairment; AD = Alzheimer’s disease; non-pTau IgM = specific IgM binding to non-phosphorylated tau 196-207)