Understanding Your Blood Test: What It Is, Why It's Done, and What the Results Mean
This blood test detects abnormal prion proteins that can indicate rare but serious neurodegenerative diseases affecting the brain.
{"Detects abnormal prion proteins in the blood using a technique called immunoblot","Used to help diagnose rare brain diseases like Creutzfeldt-Jakob disease (CJD)","Sample is collected through a simple blood draw","Results help doctors distinguish prion diseases from other neurological conditions","Abnormal results require further confirmation with additional tests"}
Key facts at a glance
- LOINC
- 74036-5
- Short code
- PrP-IB
- Synonyms
- Abn Prion Prot Tiss IB
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red top serum collection tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 100
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–100 years
- Method
- Immunoblot (Western blot) analysis using anti-prion protein antibodies
- CPT
- 81401
- SNOMED
- 371949004
- Specimen volume
- 5-10 mL of whole blood, yielding approximately 2-3 mL of serum
- Stability
- Serum should be separated from cells within 2 hours of collection. Store at 2-8°C if testing within 24 hours. For long-term storage, freeze at -70°C or below. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 20
- TAT
- 72–168 hours
- Order
- routine
What is this test, what exactly does it measure in your body, and what can it tell your doctor about your overall health?
This test looks for abnormal (misfolded) prion proteins in your blood. Prions are unusual proteins that can cause serious brain diseases when they become abnormal. The test uses a method called immunoblot (Western blot) to detect these specific proteins in your serum (the liquid part of your blood after cells are removed).
Why might I need this test, and what symptoms, conditions, or risk factors could lead my doctor to order it for me?
Your doctor may order this test if you have symptoms suggesting a prion disease, such as rapidly worsening dementia, muscle stiffness, coordination problems, or unusual movements. Prion diseases are rare but very serious conditions that affect the brain and nervous system.
How is the test performed, what should I do to prepare for it, and what can I expect to feel during the procedure itself?
A healthcare professional will draw a small blood sample from a vein in your arm. The blood is then sent to a laboratory where technicians use special techniques to detect abnormal prion proteins. You do not need to fast or make any special preparations before this test.
What do the results mean, what do normal and abnormal values indicate, and when will my doctor go over them with me?
A positive result (abnormal prion protein detected) suggests the presence of a prion disease, but additional tests are usually needed to confirm the diagnosis. A negative result does not completely rule out prion disease, as the proteins may not be detectable in early stages. Your doctor will interpret these results together with your symptoms, physical exam, and other test findings.
Reference range
Normal: <100 pg/mLN/A
No special patient preparation required. Standard venipuncture procedures apply. Inform patient that this is a specialized test for prion disease suspicion.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to help diagnose prion diseases, most commonly Creutzfeldt-Jakob disease (CJD). These are rare but fatal conditions that cause rapid deterioration of brain function. Early detection can help guide care and allow families to plan for the future. The test also helps differentiate prion diseases from other conditions that cause similar symptoms, such as Alzheimer's disease, Huntington's disease, or other forms of dementia.
Prion diseases can be sporadic (occurring randomly), inherited (genetic), or acquired through exposure to infected tissue. This test aids in identifying the sporadic form, which accounts for most cases. While there is currently no cure for prion diseases, accurate diagnosis is essential for proper medical management and family counseling.
Frequently asked questions
Is this test painful?
How long does it take to get results?
Can prion diseases be cured?
Is prion disease hereditary?
Can I catch a prion disease from another person?
Sources
- 1
- 2
- 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