Concentrations of metals, beta-amyloid and tau-markers in cerebrospinal fluid in patients with Alzheimer's disease

Background/aims: In this study, metal concentrations were related to the levels of well-known Alzheimer markers in cerebrospinal fluid (CSF), such as amyloid-beta (Abeta), total tau (T-tau) and phosphorylated-tau (P-tau).

Methods: Concentrations of 19 metals (Mg, Ca, V, Mn, Fe, Co, Ni, Cu, Zn, Se, Rb, Sr, Mo, Cd, Sn, Sb, Cs, Hg and Pb by inductively coupled plasma-mass spectrometry) and the levels of Abeta, T-tau and P-tau in CSF were determined (xMAP technology) in 264 patients with Alzheimer's disease (AD), and in 54 healthy referents.

Results: The AD subjects showed positive correlations between CSF-T-tau and CSF-P-tau versus CSF-Mn (r(s) = 0.22, p = 0.004; r(s) = 0.18, p = 0.021). CSF-T-tau, however, showed a negative correlation with CSF-Cs (r(s) = -0.17; p = 0.027). In subjects with severe AD, CSF-Abeta showed a strong positive correlation with CSF-Cs (r(s) = 0.49; p = 0.026), while CSF-T-tau showed a strong negative correlation with CSF-Cs (r(s) = -0.49; p = 0.026). Also, CSF P-tau was negatively associated with CSF-Cs (r(s) = -0.41; p = 0.06).

Conclusion: The different relationships between the CSF-levels of Abeta and tau-markers versus the levels of CSF-Mn and CSF-Cs may be due to different binding affinity between these metals and metal binding proteins in the CSF and the surrounding brain.