Читать книгу Neurology - Charles H. Clarke - Страница 73

In health, the CSF is maintained as a protein‐poor solvent in which are dissolved proteins derived mainly from brain tissue. The normal levels of CSF antibodies, amyloid beta, tau and phosphotau proteins are a baseline from which change indicates disease.

When there is a dysfunctional BBB, CSF total protein contains contributions from both CNS and systemic compartments, but this is non‐specific. Analysis of specific proteins is more useful.

 Albumin: no albumin is produced in the normal CNS. Any CSF albumin is present either via direct transport or leakage through a dysfunctional BBB.

 IgG: in health, all the CSF IgG is actively transported across the BBB. A raised CSF IgG in comparison to the serum (raised CSFIgG : serumIgG) or the IgG quotient (QIgG) can indicate disease.

 Other solutes such as a‐beta amyloid proteins, tau, neurofilament proteins, S‐100 β and 14‐3‐3 protein can also be measured. Their profiles can provide biomarker support for the diagnosis of Alzheimer’s disease versus frontotemporal dementia and other degenerative diseases (Chapter 5).