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Adenosinedeaminasecsfccnc

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

A test measuring adenosine deaminase enzyme levels in cerebrospinal fluid to help diagnose infections, particularly tuberculosis affecting the brain and surrounding membranes.

Quick summary

{"Measures ADA enzyme levels in the fluid surrounding the brain and spinal cord","Helps doctors distinguish between different types of meningitis, especially tuberculosis","A lumbar puncture (spinal tap) is required to collect the CSF sample","Elevated levels suggest possible tuberculous meningitis","Results are typically available within a few days"}

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

Key facts at a glance

LOINC
35703-8
Short code
ADA CSF
Synonyms
Adenosine deaminase CSF-cCnc
Category
chemistry
Sample
csf
Container
Sterile CSF collection tube (polypropylene tube)
Units
N/A
Ref low
0
Ref high
8
Critical range
— – 15 N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
Enzymatic spectrophotometric assay
CPT
84311
SNOMED
271510004
Specimen volume
1-2 mL CSF minimum
Stability
Room temperature: 4-6 hours; Refrigerated (2-8°C): 24-48 hours; Frozen (-20°C): several weeks
Hemolysis max
200
TAT
24–72 hours
Order
routine

What is this test?

The Adenosine Deaminase (ADA) test measures the amount of an enzyme called adenosine deaminase in your cerebrospinal fluid (CSF). CSF is the clear, protective liquid that surrounds your brain and spinal cord. This test is primarily used to help doctors determine if you have tuberculous meningitis, a serious infection of the membranes surrounding the brain and spinal cord caused by tuberculosis bacteria.

Why is this test performed?

Your doctor may order this test if you have symptoms of meningitis such as severe headache, fever, stiff neck, confusion, or sensitivity to light. The ADA test helps differentiate between different causes of meningitis: bacterial, viral, fungal, or tuberculous. Tuberculous meningitis is a dangerous condition that requires specific treatment, and detecting elevated ADA levels can provide important clues for diagnosis.

How is the sample collected?

A lumbar puncture, commonly called a spinal tap, is performed to collect the CSF sample. During this procedure, you will lie on your side or sit up while a healthcare professional inserts a thin needle between two vertebrae in your lower spine to draw out the fluid. The area will be numbed with local anesthetic to minimize discomfort. The procedure typically takes about 15-30 minutes.

What do the results mean?

Elevated levels of ADA in CSF are strongly associated with tuberculous meningitis. However, your doctor will consider your symptoms, other test results, and clinical history to make a final diagnosis. Normal or low ADA levels do not completely rule out tuberculosis, as not all cases show elevated ADA. Other conditions may occasionally cause mild elevations as well.

Reference range

Normal: 0-8 U/L. Values above 8-10 U/L suggest tuberculous meningitis. Values typically elevated in TB meningitis (often >15 U/L), but may be mildly elevated in other meningeal infections.N/A

Specimen: csf

No special preparation required. Patient should be informed about the lumbar puncture procedure and possible side effects (post-lumbar puncture headache).

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings2

Frequently asked questions

Is the lumbar puncture painful?
A local anesthetic is used to numb the area, so you will feel some pressure but minimal pain during the procedure. Some people experience a brief headache afterward, which can usually be managed with rest and fluids.
How long does it take to get results?
Results are typically available within 2-5 days, depending on the laboratory. Your healthcare provider will contact you with the results or discuss them at your follow-up appointment.
What happens if my ADA levels are elevated?
Elevated ADA levels suggest the possibility of tuberculous meningitis. Your doctor will likely order additional tests to confirm the diagnosis and begin appropriate treatment with anti-tubercular medications if needed.
Can this test diagnose other conditions?
While primarily used for TBM, slightly elevated ADA levels may occur in other conditions affecting the central nervous system, including some fungal infections, lymphomas, or other inflammatory conditions. Your doctor will interpret results in context of your overall clinical picture.
  1. 1
    Mayo Clinic Laboratories - CSF Adenosine DeaminaseSource
  2. 2
    National Institutes of Health - Tuberculous Meningritis DiagnosisSource

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