###1: Lactate Dehydrogenase 5 (LDH-5) in Cerebrospinal Fluid by Electrophoresis
###3: This test examines the amount of the LDH-5 isoenzyme in cerebrospinal fluid using electrophoresis. It may help evaluate tissue injury or inflammation affecting the central nervous system.
["###4: An elevated LDH-5 result may support central nervous system inflammation or tissue injury but is not diagnostic by itself."]
Key facts at a glance
- LOINC
- 51522-1
- Short code
- LDH5 CFr CSF Elph
- Synonyms
- LDH5 CFr CSF Elph
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Ref low
- 140
- Ref high
- 280
- Critical range
- 7.2 N/A – 7.6 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- electrophoresis
- CPT
- 83615
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
###5: What the Test Measures
###6: Lactate dehydrogenase is an enzyme found in many tissues. Electrophoresis separates its isoenzymes, allowing the laboratory to measure the LDH-5 fraction specifically in cerebrospinal fluid.
###7: Why It May Be Ordered
###8: This test may be ordered when cerebrospinal fluid is being evaluated for possible inflammation, infection, bleeding, or tissue damage involving the brain or spinal cord.
###9: How the Sample Is Collected
###10: Cerebrospinal fluid is usually obtained by lumbar puncture, commonly called a spinal tap. A thin needle is inserted into the lower back to collect the fluid for laboratory analysis.
###11: Understanding the Result
###11: The result is interpreted with your symptoms, examination findings, and other cerebrospinal fluid tests. A higher LDH-5 level can occur with several conditions, so it cannot identify a single diagnosis alone.
Reference range
Adult: 140-280 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
###13: Clinical significance: Elevated LDH-5 in cerebrospinal fluid may reflect tissue injury or inflammation within the central nervous system. However, findings are not specific and should be interpreted by a clinician alongside other laboratory and clinical information.
Short name
###2: CSF LDH-5 Electrophoresis
Frequently asked questions
###14: Is this the same as a routine serum LDH test?
###16: Does the test require special preparation?
###18: Can this test diagnose a specific condition?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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