Table 2.
Serum and CSF NfL concentration
| Baseline Visit Only | All Available Visits | ||||
|---|---|---|---|---|---|
| Serum NfL | CSF NfL | Serum NfL | CSF NfL | ||
| Control (N=34; total 56 visits) | N=32 d | N=15 f | 53 visits d | 18 visits | |
| Original scale (pg/ml) | Median (Range) |
9.0 (2.2-33.1) |
491 (306-1,573) |
10.7 (0.4-33.5) |
482 (306-2,460) |
| Log-transformed a | Mean ± SD (Range) |
2.4 ± 0.7 (1.0-3.5) |
6.3 ± 0.6 (5.7-7.4) |
2.5 ± 0.7 (0.01-3.5) |
6.4 ± 0.6 (5.7-7.8) |
| At-Risk (N=84; total 213 visits) | N=75 e | N=50 f | 195 visits e | 110 visits | |
| Original scale (pg/ml) | Median (Range) |
12.6 (1.1-62.4) |
641 (301-2,719) |
13.9 (1.1-75.6) |
681 (225-3,629) |
| Log-transformed a | Mean ± SD (Range) |
2.5 ± 0.7 (0.6-4.1) |
6.5 ± 0.5 (5.7-7.9) |
2.7 ± 0.7 (0.6-4.3) |
6.6 ± 0.6 (5.4-8.2) |
| Converter (N=10 b; total 28 visits c) | N=10 | N=3 f | 28 visits | 10 visits g | |
| Original scale (pg/ml) | Median (Range) |
19.1 (6.9-104.3) |
2,558 (772-5,679) |
86.2 (6.9-720.4) |
7,664 (772-16,678) |
| Log-transformed a | Mean ± SD (Range) |
3.1 ± 1.0 (2.0-4.7) |
7.7 ± 1.0 (6.6-8.6) |
4.3 ± 1.3 (2.0-6.6) |
8.6 ± 1.0 (6.6-9.7) |
| Affected (N=17; total 44 visits) | N=17 | N=6 | 44 visits | 16 visits | |
| Original scale (pg/ml) | Median (Range) |
120.5 (20.5-554.7) |
10,655 (2,142-14,964) |
99.0 (20.5-554.7) |
9,413 (2,142-21,658) |
| Log-transformed a | Mean ± SD (Range) |
4.8 ± 0.8 (3.1-6.3) |
9.0 ± 0.8 (7.7-9.6) |
4.7 ± 0.7 (3.1-6.3) |
9.0 ± 0.8 (7.7-10.0) |
Baseline = first visit at which serum sample was available (with or without contemporaneous CSF collection)
N = number of participants. Visits = number of person-visits.
Natural algorithm
All 10 converters were pre-symptomatic at baseline.
The 28 person-visits in the converter group included visits from when participants were pre-symptomatic and after phenoconversion.
In the control group, serum NfL at 3 person-visits (2 baseline, 1 follow-up) were below the level of detection and not included in the summary statistics above.
In the pre-symptomatic group, serum NfL at 18 person-visits (9 baseline, 9 follow-up) were below the level of detection and not included in the summary statistics above.
An additional N=1 control, N=6 at-risk, and N=3 converters had CSF NfL at follow up (but not baseline) visits.
In the converter group, CSF NfL at 1 baseline visit was below the level of detection and not included in summary statistics above.