C-reactive protein (CRP) by nephelometry (serum/plasma)
This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your body.
["CRP helps doctors assess inflammation, often used to monitor conditions like infections, autoimmune diseases, or after surgery."]
Key facts at a glance
- LOINC
- 17188-4
- Short code
- CD66e
- Synonyms
- CD66e Cells NFr Bld
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA) tube for whole blood flow cytometry; sodium heparin tube acceptable for immunophenotyping
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Flow cytometry immunophenotyping
- CPT
- 88184
- SNOMED
- 39754003
- Specimen volume
- 3-5 mL whole blood (adult); minimum 1 mL (pediatric)
- Stability
- Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-25°C). Refrigeration may affect cell viability and marker expression.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to check for signs of inflammation, monitor chronic conditions like rheumatoid arthritis or heart disease, or evaluate symptoms such as fever, joint pain, or swelling. It can also help determine if an infection is present or if your body is reacting to an injury or illness.
What to Expect Before the Test
No special preparation is needed for this test. You may have a blood sample drawn from a vein in your arm, similar to other blood tests. If you’re on blood thinners, let your provider know before the test.
What the Results Mean
Higher-than-normal CRP levels often indicate inflammation or infection. However, results alone don’t diagnose a specific condition. Your provider will consider your overall health, symptoms, and other test results to interpret the meaning.
Common Conditions Monitored
CRP is commonly used to track inflammation in conditions like heart disease, autoimmune disorders (e.g., lupus, rheumatoid arthritis), infections, or after surgeries or trauma.
Reference range
Reference ranges vary by laboratory; results expressed as percentage of total cells or absolute count. CD66e (CEA) is typically not expressed on peripheral blood cells under normal conditions.N/A
No fasting required. Standard venipuncture preparation; sample should be processed promptly to maintain cell viability.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: CRP’s Role in Healthcare
Short name
CRP (Nephelometry)
Frequently asked questions
How long does it take to get CRP test results?
Can CRP levels be affected by diet or exercise?
Is CRP the same as a white blood cell count (WBC) test?
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