Urinary Neopterin-to-Creatinine Ratio
A urine test that measures neopterin relative to creatinine to help assess cellular immune activity while accounting for urine concentration.
["This ratio can provide information about immune-system activity, but results must be interpreted alongside other clinical findings."]
Key facts at a glance
- LOINC
- 17334-4
- Short code
- Neopterin/Creat Ur
- Synonyms
- Neopterin/Creat Ur
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures neopterin in urine and compares it with the amount of creatinine in the same sample. Neopterin is produced by activated immune cells, while creatinine is used to help adjust for variations in urine concentration.
Why might I need this test?
A clinician may order this test to help evaluate cellular immune-system activity, particularly in people with HIV or other immunodeficiencies. It may also be used in selected situations involving immune suppression, such as monitoring some transplant recipients.
How is the test performed?
You provide a urine sample according to the laboratory’s instructions. The laboratory measures neopterin and creatinine and calculates their ratio. The type of urine collection, such as a random or timed sample, depends on the test requested.
How do I prepare for the test?
Follow the laboratory’s urine-collection instructions carefully, including any specified collection time or handling requirements. Your clinician will tell you if medication changes, dietary restrictions, or another type of specimen collection are needed.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated ratio may indicate increased immune-cell activation and can occur with infections, inflammatory conditions, or other causes of immune stimulation. A lower ratio may be associated with reduced cellular immune activity, including some immunodeficiencies. Results can vary with urine collection, age, medications, pregnancy, and other factors, so the ratio should be interpreted by a clinician and, when appropriate, compared with the laboratory’s reference range.
Short name
Urine Neopterin/Creatinine Ratio
Frequently asked questions
What does the urine neopterin-to-creatinine ratio measure?
What is neopterin?
Does an abnormal result 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