Albumin (CSF)
Sample Type: Cerebrospinal Fluid (CSF)

Purpose:
The CSF albumin test measures the concentration of albumin in the cerebrospinal fluid. Albumin is a protein normally found in the blood but present in only small amounts in healthy CSF.

Clinical Significance:

Increased CSF albumin levels typically indicate blood-brain barrier (BBB) dysfunction or increased permeability, allowing proteins from the blood to enter the CSF.

It is not produced within the central nervous system (CNS), so any elevation suggests leakage from serum.

Common Clinical Uses:

To assess blood-brain barrier integrity

As part of CSF/serum albumin ratio (albumin quotient) to distinguish intrathecal synthesis from passive diffusion in conditions like:

Multiple sclerosis (MS)

Meningitis

Encephalitis

Guillain-Barré syndrome

Tumors or trauma affecting the CNS

Interpretation Tip:

Normal albumin quotient: suggests intact BBB

Elevated quotient: suggests compromised BBB