Total-tau in cerebrospinal fluid of patients with multiple sclerosis decreases in secondary progressive stage of disease and reflects degree of brain atrophy

Figures & data

Table I. Clinical characteristic of the study population.

	All patients	RR	SP
Age (mean ± SD) in years	36.2 ± 11.4	32.8 ± 9.1	44.5 ± 12.2
Range	21–62	21–52	21–62
Disease duration (mean ± SD) in years	6.4 ± 5.5	4.6 ± 4.0	10.8 ± 6.1
Range	1–28	1–18	2–28
EDSS (mean ± SD)	3.6 ±1.8	2.7 ± 1.0	6.0 ± 1.2
Range	1–7.5	1–4.5	4–7.5
MSSS (mean ± SD)	6.0 ± 2.1	5.3 ± 1.8	7.8 ± 1.8
Range	0.7–9.6	0.7–8.6	2.8–9.6

EDSS = Expanded Disability Status Scale; MSSS = Multiple Sclerosis Severity Score; RR = relapsing-remitting; SP = secondary progressive.

Table II. Summarized results of CSF and serum tau protein concentrations and brain morphometric measurements of the study population.

	All patients	RR	SP
CSF t-tau in pg/mL (median)	105	110	68
Range	60–305	60–305	60–205
CSF p-tau in pg/mL (median)	35.1	38	30
Range	15.6–103	15.6–103	16–78
Serum p-tau in pg/mL (median)	29.2	27.1	33.5
Range	15.6–472.3	15.6–115.3	15.6–472.3
Brain volume in mL (mean ± SD)	1317 ± 165.6	1332 ± 160	1279 ± 179
CSF volume in mL (mean ± SD)	214.8 ± 55.6	198 ± 38	256 ± 71
Brain parenchymal fraction (mean ± SD)	0.86 ± 0.04	0.87 ± 0.03	0.83 ± 0.04

CSF = cerebrospinal fluid; t-tau = total-tau; p-tau = phospho181Thr-tau; pg/mL = picograms per mL; RR = relapsing-remitting; SP = secondary progressive.

Figure 1. CSF total-tau concentrations in different MS populations (box represents median with interquartile 25th–75th range; whiskers show 10th–90th percentile range; dots show values beyond defined percentiles). Mann–Whitney U P = 0.01. (CSF = cerebrospinal fluid; t-tau = total-tau; pg/mL = picograms per mL; RR = relapsing-remitting; SP = secondary progressive).

Figure 2. Negative correlation of t-tau with EDSS in the whole study population (y = –0.01x + 4.8) (linear regression line with 95% CI, R² = 0.14, P = 0.04; Spearman R = –0.58, P = 0.0006). (EDSS = Expanded Disability Status Scale; t-tau = total-tau; pg/mL = picograms per mL).

Figure 3. Negative correlation of EDSS with BPF in the whole study population (y = –25x + 25) (linear regression line with 95% CI, R² = 0.26, P = 0.0002; Pearson R = –0.51, P = 0.0002). (BPF = brain parenchymal fraction; EDSS = Expanded Disability Status Scale).

Figure 4. Negative correlation of MSSS and BPF in the whole study group (y = –25x + 27) (linear regression line with 95% CI, R² = 0.18, P = 0.002; Pearson R = –0.42, P = 0.002). (MSSS = Multiple Sclerosis Severity Score; BPF = brain parenchymal fraction).

Figure 5. Negative correlation of brain volume with EDSS in the whole study population (y = –0.004x + 9.4) (linear regression line with 95% CI, R² = 0.15, P = 0.007; Pearson R = –0.38, P = 0.007). (EDSS = Expanded Disability Status Scale).