Table 1.
Demographic and biomarker characteristics of the study participants.
| Control | MCI | Mild AD | Mod AD | FTD | ALS | PSP | p | |
|---|---|---|---|---|---|---|---|---|
| Characteristics | (n = 23) | (n = 24) | (n = 41) | (n = 20) | (n = 8) | (n = 8) | (n = 8) | # |
| Age, mean (SD), y | 64.7 (10.8) | 72.0 (7.1) | 71.9 (8.1) a | 73.3 (7.2) a,b | 66.4 (5.2) | 58.0 (14.1) | 74.0 (6.0) | <0.001 |
| Female sex, n (%) | 8 (34.8) | 14 (58.4) | 22 (53.7) | 13 (65.0) | 3 (37.4) | 3 (37.5) | 4 (50.0) | ns |
| Disease duration, mean (SD), y | - | 2.4 (1.4) | 2.6 (1.7) | 4.0 (1.6) c,d,e | 3.3 (1.2) | 1.8 (0.9) | 4.1 (2.2) | <0.01 |
| MMSE score, mean (SD) | - | 25.4 (3.2) | 21.6 (3.0) e | 16.0 (4.3) f,g | - | - | - | <0.0001 |
| CDR, mean (SD) | 0 | 0.5 | 1,0 | 2.2 (0.4) | - | - | - | NA |
| APOE ε4 carrier, No./Total (%) | 0/15 (0.0%) | 9/15 (60.0%) h | 9/18 (50.0%) h | 2/9 (22.2%) | - | - | - | <0.0001 |
| CSF biomarkers | ||||||||
| Aβ42, mean (SD), pg/mL | 1026.1 (278.9) | 380.0 (89.3) | 355.9 (103.8) | 360.9 (88.0) | 832.2 (188.5) | 701.2 (224.1) | 1058.7 (219.3) | NA |
| T-tau, mean (SD), pg/mL | 303.9 (110.7) | 928.8 (545.0) | 836.4 (444.0) | 871.2 (389.7) | 305.4 (162.0) | 137.0 (56.5) | 252.3 (88.7) | NA |
| CSF KYNA, mean (SD), µg/L | 3.9 (2.9) | 9.8 (6.9) a | 11.1 (7.2) i | 10.5 (7.4) h | 5.6 (2.5) | 4.0 (1.4) | 4.7 (3.7) | <0.0001 |
| CSF TRP, mean (SD), µg/L | 73.7 (19.7) | 75.5 (20.6) | 77.1 (25.3) | 79.7 (27.0) | 78.4 (18.6) | 67.5 (23.6) | - | ns |
| Ratio KYNA/TRP, mean (SD) | 0.06 (0.06) | 0.13 (0.09) | 0.16 (0.13) h | 0.17 (0.17) | 0.08 (0.05) | 0.07 (0.04) | - | <0.05 |
| Plasma biomarkers | ||||||||
| (n = 20) | (n = 11) | (n = 17) | (n = 9) | |||||
| Plasma KYNA, mean (SD), µg/L | 164.0 (118.5) | 179.4 (126.9) | 167.4 (126.4) | 176.9 (82.8) | - | - | - | ns |
| Plasma TRP, mean (SD), µg/L | 2333.3 (1216.3) | 2022.7 (1335.2) | 2104.7 (822.7) | 1956.0 (1259.3) | - | - | - | ns |
| Ratio KYNA/TRP, mean (SD) | 0.08 (0.07) | 0.10 (0.07) | 0.08 (0.09) | 0.11 (0.08) | - | - | - | ns |
Abbreviations: MCI, mild cognitive impairment; Mild AD, mild Alzheimer’s disease; Mod AD, moderate–severe Alzheimer’s disease; FTD, frontotemporal dementia; ALS, amyotrophic lateral sclerosis; PSP, progressive supranuclear palsy; MMSE, Mini-Mental State Examination; CDR, Clinical Dementia Rating; Aβ42, β-amyloid 42; t-tau, total tau; KYNA, kynurenic acid; TRP, tryptophan; NA, not applicable; ns, non-significant. # p-value indicates statistical difference between all groups; a p < 0.05 vs. control; b p < 0.05 vs. ALS; c p < 0.05 vs. MCI; d p < 0.05 vs. Mild AD; e p < 0.01 vs. ALS; f p < 0.001 vs. MCI; g p < 0.01 vs. Mild AD; h p < 0.01 vs. control; i p < 0.0001 vs. control.