Fluid biomarkers | Biological function | Unspecified FTD | PSP | FTD-GRN | FTD-C9orf72 | FTD-MAPT | Ref. | |||
P | S | P | S | P | S | |||||
GFAP | Marker of astrogliosis | ↑ | – | ↑ | – | – | – | – | 40 41 | |
sTREM2 | Microglial activation marker | - | ↑ | – | – | 35 36 | ||||
YKL40 | Proinflammatory marker of activated astrocytes | ↑ | ↑ | – | ↑ | 37 38 | ||||
CHIT1 | Microglial activation marker | ↑ | – | – | 37 38 | |||||
IL-1β | Cytokine with largely proinflammatory activity | ↑ | 51 | |||||||
IL-6 | Cytokine with largely proinflammatory activity | ↑ | ↑ | – | ↑ | – | 43 44 46 47 51 | |||
– | – | |||||||||
IL-8 (CXCL8) | Cytokine with largely proinflammatory activity | ↑ | 44 | |||||||
IL-11 | Cytokine with largely anti-inflammatory activity | ↑ | 47 | |||||||
IL-12 | Cytokine with largely proinflammatory activity | ↓ | 48 | |||||||
IL-15 | Cytokine with largely proinflammatory activity | ↑ | ↓ | 42 49 | ||||||
– | ||||||||||
IL-18 | Cytokine with largely proinflammatory activity | – | – | – | 46 | |||||
TNF-α | Cytokine with largely proinflammatory activity | ↑ | ↑ | – | ↑ | 46 50–52 | ||||
– | ||||||||||
↓ | ||||||||||
IP-10/CXCL10 | Chemokine with largely proinflammatory activity | – | ↑ | 42 44 | ||||||
MCP-1/CCL2 | Chemokine with largely proinflammatory activity | ↑ | – | 42 44 | ||||||
RANTES/ CCL5 | Cytokine with largely proinflammatory activity | ↓ | ↓ | 42 | ||||||
TGF-β | Cytokine with largely anti-inflammatory activity | ↑ | 50 |
Blue, in cerebrospinal fluid; green, in blood and cerebrospinal fluid; red, in blood; yellow, in neuron-derived exosomes from plasma.
– indicates (unchanged levels); ↑ indicates increased levels; ↓ indicates decreased levels; all compared with controls.
CHIT1, chitotriosidase; C9orf72, chromosome 9 open reading frame 72; FTD, frontotemporal dementia; GFAP, glial fibrillary acidic protein; GRN, progranulin; IL, interleukin; MAPT, microtubule-associated protein tau; MCP-1, monocyte chemoattractant protein-1; P, presymptomatic; PSP, progressive supranuclear palsy; RANTES, regulated on activation, normal T cell expressed and secreted; Ref, reference; S, symptomatic; sTREM2, soluble triggering receptor expressed on myeloid cells 2; TGF-β, transforming growth factor β; TNF-α, tumour necrosis factor α.