Serum/Plasma Cytokeratin 19 Fragment (Total)
This test measures the presence of a protein fragment derived from cytokeratin 19, a component of cells in certain tissues, including the gastrointestinal tract and lungs. It’s often used to monitor conditions affecting these tissues.
["This test helps track certain cancers or inflammation in organs like the stomach or lungs."]
Key facts at a glance
- LOINC
- 19182-5
- Short code
- CK 19 SerPl-aCnc
- Synonyms
- CK 19 SerPl-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 22
- Ref high
- 198
- Critical range
- — – 10000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82553
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Is Cytokeratin 19 Fragment Used For?
Cytokeratin 19 (CK19) is a protein found in cells lining organs such as the stomach, lungs, and intestines. When these cells are damaged or cancerous, CK19 fragments can be released into the bloodstream. This test detects these fragments to help diagnose or monitor conditions like gastrointestinal cancers (e.g., stomach or esophageal cancer), lung cancer, or inflammatory diseases such as pancreatitis or certain infections.
How Is the Test Performed?
A blood sample is drawn from a vein in your arm. The blood is then processed to separate the serum or plasma, where the CK19 fragments are measured using a sensitive immunoassay technique. This test does not require fasting and is typically done as part of routine monitoring or diagnostic workup.
When Might You Need This Test?
Your healthcare provider may order this test if you have symptoms like unexplained weight loss, abdominal pain, persistent nausea, or unexplained fatigue. It may also be used during follow-up for patients with known gastrointestinal or lung cancers, or those with conditions like chronic pancreatitis or severe infections.
What Are the Possible Results?
Results are not given in absolute numbers because reference ranges vary by lab and patient factors. Elevated levels may suggest tissue damage, inflammation, or cancer, while normal levels do not definitively rule out these conditions. Your doctor will interpret results in the context of your medical history and symptoms.
Reference range
Adult males: 22-198 U/L; Females: 22-198 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.
Elevated CK19 levels can indicate underlying issues such as cancer (e.g., stomach, lung, or pancreatic cancer), severe inflammation (e.g., pancreatitis), or infections. It’s often used alongside other tests to improve diagnostic accuracy. However, it is not a standalone test for cancer diagnosis and should be considered alongside clinical findings, imaging, and other lab tests.
Short name
Cytokeratin 19 Fragment
Frequently asked questions
Why would my doctor order this test?
What does an elevated result mean?
Do I need to prepare for 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 17, 2026. · Read our editorial policy