Simvastatin-Neutralizing IgM Antibodies, Serum/Plasma — Qualitative
A qualitative blood test that detects IgM antibodies capable of interfering with simvastatin, which can occur in some statin-associated autoimmune muscle reactions.
["Detected antibodies may help explain severe muscle injury or weakness associated with simvastatin."]
Key facts at a glance
- LOINC
- 72951-7
- Short code
- Simvastatin (neut) IgM SerPl Ql FC
- Synonyms
- Simvastatin (neut) IgM SerPl Ql FC
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- flow-cytometry
- CPT
- 84484
- SNOMED
- 302774002
- 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 this test?
This test looks for simvastatin-neutralizing IgM antibodies in serum or plasma. These antibodies are occasionally found in people with statin-associated immune-mediated muscle disease.
Why might I need this test?
It may be ordered when a patient develops unexplained muscle pain, weakness, dark urine, or elevated muscle enzymes after taking simvastatin or another statin. The result can help doctors evaluate whether an immune reaction to the medication is contributing to muscle injury.
How is the test performed?
A blood sample is collected, and the laboratory tests the serum or plasma for the presence of simvastatin-neutralizing IgM antibodies. The result is reported as detected or not detected.
How do I prepare for the test?
No special preparation is usually required. Tell your healthcare professional which statin you take, when you started it, and any recent changes in dose or medication.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Detecting these antibodies may support a diagnosis of statin-associated immune-mediated necrotizing myopathy, particularly when severe muscle weakness, muscle pain, or muscle injury is present. A positive result should be interpreted with symptoms, medication timing, laboratory findings, and other clinical evidence. A negative result does not completely exclude a statin-related immune reaction, especially if the test is performed after treatment has stopped.
Short name
Simvastatin-Neutralizing IgM Antibodies
Frequently asked questions
What are simvastatin-neutralizing IgM antibodies?
What symptoms may lead to this test being ordered?
Does a positive result mean I must stop simvastatin?
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