Table 1 Summary of studies for YKL-40.
Study no. | Study | Groups analyzed | Outcome measure | Magnitude of measure: mean (SD) or median (IQR) | Statistical analysis | ||
|---|---|---|---|---|---|---|---|
1 | Abu-Rumeileh et al. [56] | Control (n = 28) | AD (n = 38) | CSF YKL-40 level | Control (147 [116–158]) ng/mL | AD (240 [177–289]) | p < 0.001 Kruskal–Wallis test |
2 | Abu-Rumeileh et al. [55] | Control (n = 40) | AD (n = 40) | CSF YKL-40 level | Control (145 [115–161]) ng/mL | AD (240 [176–293]) | p < 0.001 Kruskal–Wallis test |
3 | Antonell et al. [54] | Healthy control (n = 50) | Preclinical AD (n = 21) | CSF YKL-40 level | Control (217.23 [153.86–271.37]) ng/mL | Preclinical AD (325.14 [237.24–363.73]) | Preclinical AD vs. control (p = 0.726) |
MCI due to AD (n = 56) | MCI due to AD (347.24 [257.71–397.06]) | MCI due to AD vs. control (p = 0.025) | |||||
AD dementia (n = 108) | AD dementia (305.12 [247.33–396.56]) | AD dementia vs. control (p = 0.010) | |||||
4 | Brosseron et al. [61] | Control (n = 74) | SCD (n = 99) | Serum levels of YKL-40 | Control (83 ± 151 [23–1020]) ng/mL | SCD (78 ± 332 [27–3178]) | Kruskal–Wallis test followed by ANCOVA p = 0.108 |
MCI (n = 75) | MCI (111 ± 100 [17–488]) | ||||||
AD dementia (n = 38) | AD dementia (138 ± 112 [22–514]) | ||||||
5 | Janelidze et al. [57] | Control–Aβ− (n = 362) | MCI–Aβ− (n = 114) | CSF levels of YKL-40 | Compared with the control–Aβ− group, the CSF levels of YKL-40 were increased in all groups with pathologic Aβ+ status (control–Aβ+a, MCI–Aβ+b, and AD dementiac) Furthermore, YKL-40 levels were higher in AD dementia than in control–Aβ+d and MCI–Aβ+e | One-way ANOVA ap < 0.001 bp = 0.005 cp < 0.001 dp = 0.003 ep ≤ 0.001 | |
Control–Aβ+ (n = 146) | MCI–Aβ+ (n = 142) | ||||||
AD dementia (n = 57) | |||||||
6 | Olsson et al. [59] | Control (n = 65) | AD dementia (n = 96) | CSF levels of YKL-40 | Control (194,622 ± 76,326 ng/L) | AD dementia (241,582 ± 100,701 ng/L) | ANOVA p < 0.01 |
MCI due to AD (n = 61) | MCI due to AD (209,077 ± 74,859 ng/L) | ||||||
Stable MCI (n = 81) | Stable MCI (171,687 ± 68,367 ng/L) | ||||||
7 | Pereira et al. [58] | Cognitively unimpaired Aβ− (n = 217) | Cognitively impaired Aβ+ (n = 78) | CSF levels of YKL-40 | Cognitively unimpaired Aβ− (162.0 [38.3–458.2] ng/mL) | Cognitively impaired Aβ+ (220.3 [63.9–523.5] ng/mL) | Kruskal–Wallis test p < 0.001 |
Cognitively unimpaired Aβ+ (n = 71) | Cognitively impaired Aβ− (n = 63) | Cognitively unimpaired Aβ+ (211.2 [80.9–374.8] ng/mL) | Cognitively impaired Aβ− (184.6 [68.1–371.0] ng/mL) | ||||
8 | Prins et al. [62] | Aβ+ (n = 50) | Aβ− (n = 50) | Plasma levels of YKL-40 | Aβ− (82,947.1 ± 83,418.38 pg/mL for n = 49) | Aβ+ (54,662.3 ± 39,697.31 pg/mL for n = 49) | Independent t-test p = 0.397 |
9 | Teitsdottir et al. [60] | CSF non-AD profile (n = 24) | CSF AD profile (n = 28) | CSF levels of YKL-40 | Non-AD profile (165 (83–399) ng/mL) | AD profile (203 [124–367] ng/mL) | Mann–Whitney U test p = 0.12 |
