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Cerebrospinal fluid (CSF) protein concentration (mass concentration)

Published: August 9, 2026Updated: August 16, 2026

This test measures the total protein found in your cerebrospinal fluid (the fluid surrounding your brain and spinal cord). It can help identify issues like inflammation, infections, or blood leakage into the CSF.

Quick summary

["Protein levels in CSF may signal neurological conditions or bleeding in the brain area."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
106957-4
Short code
CD200CD19BM
Synonyms
Cells.CD200+CD19+ NFr Mar FC
Category
chemistry
Sample
serum
Container
Sterile bone marrow aspirate collected in heparinized tube (sodium heparin or lithium heparin) or EDTA tube for flow cytometry analysis; sterile RPMI or tissue culture medium may be used for transport
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
88184
SNOMED
42861000122100
Specimen volume
1-3 mL of bone marrow aspirate; first-pull aspirate preferred to minimize peripheral blood dilution
Stability
Specimen should be processed within 24 hours of collection when stored at room temperature (18-25°C); up to 48 hours if stored at 2-8°C. Viability and antigen expression may decline with prolonged storage. Live cell processing is essential for accurate immunophenotyping.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
24–72 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like severe headaches, neck stiffness, confusion, or neurological problems. It’s also used to diagnose conditions such as meningitis, multiple sclerosis, or subarachnoid hemorrhage. Sometimes, it’s part of a broader evaluation for unexplained neurological symptoms or after a head injury.

What to Expect Before the Test

You’ll likely have a small needle inserted into your lower back to collect a sample of CSF. This is called a lumbar puncture or spinal tap. You may feel a brief pinch, but it’s usually over quickly. You’ll lie on your side with your knees bent, and the area will be cleaned with an antiseptic solution.

What Happens During the Test

The collected CSF is sent to a lab for analysis. The protein concentration is measured using a specialized method, often nephelometry or turbidimetry, to determine the total protein amount in the sample.

What the Results Mean

High protein levels in CSF can indicate conditions like meningitis, multiple sclerosis, or tumors. Low levels might suggest normal pressure or certain congenital disorders. Your doctor will interpret the results in the context of your symptoms and medical history.

Reference range

Reference ranges vary by laboratory and patient population. CD200+CD19+ B-cell populations in bone marrow are typically reported as percentage of total cells or absolute count. Results should be interpreted in conjunction with clinical findings and other immunophenotypic markers. Consult laboratory-specific reference intervals.N/A

Specimen: serum

No special patient preparation required. Prior to bone marrow aspiration, informed consent must be obtained. Patients on anticoagulant therapy should be evaluated for bleeding risk. Recent chemotherapy, immunotherapy, or immunosuppressive therapy may affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CSF Protein Level

Frequently asked questions

What causes elevated CSF protein levels?
Elevated CSF protein levels can result from inflammation (e.g., meningitis), immune system disorders (e.g., multiple sclerosis), bleeding into the CSF (e.g., subarachnoid hemorrhage), or certain infections. Chronic conditions like Guillain-Barré syndrome may also be associated with higher protein levels.
What causes normal or low CSF protein levels?
Normal or low CSF protein levels are often seen in cases of normal pressure or mild neurological conditions. Rarely, genetic or congenital disorders may cause persistently low protein levels. Your doctor will assess whether these results are concerning based on your symptoms and test history.
How often should I get this test?
The frequency depends on your symptoms, diagnosis, or treatment plan. If you have an ongoing condition like multiple sclerosis, your doctor may recommend periodic monitoring. Follow-up tests are usually scheduled based on your individual care plan, not a set schedule.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy