| Alpha-2-macroglobulin |
plasma |
Inhibitor of coagulation; inhibitor of fibrinolysis |
Increased in MCI and AD |
[5,47] |
| Complement C3 |
plasma |
Most abundant protein of the complement system, enhances response |
Increased in AD |
[101–104] |
| Complement C4 |
plasma |
Protein involved in the complement system and undergoes cleavage |
Increased in AD |
[5,105] |
| C4b-binding protein |
plasma |
Inhibits C4 and binds necrotic cells |
Decreased in MCI and AD |
[47] |
| Complement C5 |
plasma |
Fifth component of the complement pathway |
Increased in MCI |
[47] |
| Complement C9 |
mRNA and protein levels, vascular amyloid deposits |
Involved in MAC formation |
Increased in AD brain areas, increased deposition in vascular plaques |
[101,102,106] |
| Complement factor H |
plasma |
Regulation of alternative pathway of the complement system, ensuring no damage to host tissue |
Increased in AD |
[5,107] |
| Fibrinogen |
plasma |
Involved in blood clotting |
Decreased in AD |
[47,104,108,109] |
| Haptogloblin |
Plasma, CSF |
Binds free haemoglobin thereby reducing its oxidative activity |
Increased in AD plasma, decreased in CSF of MCI and AD patients. Other studies show increase in CSF of AD |
[110,111] |
| Hemopexin |
plasma and CSF |
Binds heme, preserves iron levels in the body |
Increased in AD |
[105,112,113] |
| Thrombin |
Brain tissue, amyloid plaques, neurofibrillary tangles |
Coagulation protein that converts fibrinogen into fibrin, also catalyses other coagulation related reactions |
Increased in AD |
[114–116] |
| Transthyretin |
Plasma, CSF |
Carrier of the thyroid hormone thyroxine |
Decreased in AD |
[47,112,117,118] |
