Conclusions
The concentration of total tau protein level is elevated, whereas phospho-tau-181 is undetectable in the CSF of patients with early-stage MS.
Methods
Cerebrospinal fluid (CSF) was collected from 19 patients with newly diagnosed MS and 19 control subjects. All MS patients underwent neurological examination, lumbar punction, and brain magnetic resonance imaging (MRI). CSF concentrations of total and phosphorylated tau (phospho-tau-181) protein were measured using commercial enzyme-linked immunosorbent assay kits.
Results
The total tau concentration was significantly higher in the CSF of MS patients compared to controls (141.67 pg/mL, IQR 77.79-189.17 and 68.77 pg/mL, IQR 31.24-109.17, p = 0.025). In MS patients, the total tau protein positively correlated with total CSF protein (r = 0.471, p = 0.048). Significantly higher total tau concentration was measured in MS patients with higher lesion load in brain MRI (≥9 versus <9 lesions; 168.33 pg/mL, IQR 111.67-222.32 and 73.33 pg/mL, IQR -32.13-139.29-, p = 0.021). The CSF concentration of phospho-tau-181 protein was below the detection limit in both MS and control subjects. Conclusions: The concentration of total tau protein level is elevated, whereas phospho-tau-181 is undetectable in the CSF of patients with early-stage MS.