Montelukast-Induced Platelet IgG Antibody, Serum/Plasma — Qualitative, Flow Cytometry
Detects platelet-reactive IgG antibodies triggered by montelukast, which may be associated with immune-mediated low platelet counts.
["A positive result can support immune thrombocytopenia related to montelukast when combined with your symptoms and platelet count."]
Key facts at a glance
- LOINC
- 73259-4
- Short code
- Montelukast ind plt IgG SerPl Ql FC
- Synonyms
- Montelukast ind plt IgG 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 blood test looks for IgG antibodies that react with platelets when the drug montelukast is present. These drug-dependent antibodies can cause the immune system to remove platelets from the bloodstream.
Why might I need this test?
It may be ordered if you developed a low platelet count, bruising, bleeding, or small red-purple spots on the skin after taking montelukast. Results are interpreted alongside your medication history, symptoms, and other blood tests.
How is the test performed?
A blood sample is collected and separated into serum or plasma. A laboratory uses flow cytometry to determine whether the sample contains IgG that binds platelets in the presence of montelukast.
How do I prepare for the test?
No fasting is usually required, but follow any instructions from the laboratory. Tell the care team which medications you take and when you last took montelukast; do not stop prescribed medication without medical advice.
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.
A positive result indicates that montelukast-dependent platelet-reactive IgG was detected, which can support a diagnosis of drug-induced immune thrombocytopenia. A negative result does not completely exclude a medication-related reaction, so the result must be considered with your platelet count, symptoms, and other clinical findings.
Short name
Montelukast-induced platelet IgG antibody
Frequently asked questions
What does a positive result mean?
Does a negative result rule out montelukast-related thrombocytopenia?
Should I stop taking montelukast because of 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