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 or autoimmune diseases."]
Key facts at a glance
- LOINC
- 106955-8
- Short code
- CD123CD19FC
- Synonyms
- Cells.CD123+CD19+ NFr Spec FC
- Category
- chemistry
- Sample
- serum
- Container
- EDTA (lavender-top) or heparin (green-top) tube; sterile tube for bone marrow or other tissue specimens
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- flow-cytometry
- CPT
- 88184
- SNOMED
- 395124008
- Specimen volume
- 3-5 mL whole blood for peripheral blood; 1-2 mL for bone marrow aspirate; minimum 0.5 mL for other fluid specimens
- Stability
- Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-25°C). For delays beyond 24 hours, store at 2-8°C and process within 72 hours. Viability of cells may decline with prolonged storage.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order CRP testing to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate infections. It can also help guide treatment decisions for conditions like rheumatoid arthritis or certain infections.
What to Expect Before the Test
No special preparation is needed for this test. You may have a small needle inserted into a vein (usually in your arm) to draw blood. If you’re concerned about needles, let your healthcare provider know.
What the Results Mean
Higher CRP levels often indicate inflammation, but they can also be influenced by factors like stress, fever, or certain medications. Your doctor will interpret results in the context of your overall health and symptoms.
Common Conditions Monitored
CRP is commonly used to monitor conditions such as rheumatoid arthritis, inflammatory bowel disease, or after surgeries to check for infection risks.
Reference range
Reference values are laboratory-specific and depend on the gating strategy, fluorochrome panel, and acquisition parameters. Typically expressed as percentage of total cells or absolute count (cells/μL). CD123+CD19+ cells are normally rare or absent in peripheral blood.N/A
No special patient preparation required. Avoid recent blood transfusions when possible, as they may alter immunophenotyping results. Inform the laboratory of any immunosuppressive therapy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CRP (Serum/Plasma)
Frequently asked questions
How often will I need this test?
Can diet or exercise affect CRP levels?
Is there any risk or discomfort with this 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