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Clopidogrel-induced platelet-associated IgG, qualitative, by flow cytometry (serum or plasma)

Published: August 9, 2026Updated: August 16, 2026

This test looks for IgG antibodies that attach to platelets after clopidogrel exposure. A positive result may support immune-mediated thrombocytopenia caused by clopidogrel.

Quick summary

["A positive result can help identify clopidogrel as a possible cause of immune-related low platelets."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
73430-1
Short code
Clopidogrel ind plt IgG SerPl Ql FC
Synonyms
Clopidogrel ind plt IgG SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
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 the test measures

The laboratory uses flow cytometry to look for platelet-associated IgG in serum or plasma. These antibodies can react with platelets in the presence of clopidogrel.

Why it may be ordered

This test may be considered when low platelet counts develop after starting clopidogrel and other causes have not fully explained the problem. Results are interpreted with the medication history and clinical findings.

Interpreting a positive result

A positive result suggests that clopidogrel-dependent antibodies may be contributing to platelet destruction. It does not by itself prove that clopidogrel is the sole cause of the low platelet count.

Interpreting a negative result

A negative result does not completely exclude a clopidogrel-related immune reaction. Some cases may be missed because of limited antibody levels, timing, or other technical factors.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinically, this test can help support a suspected drug-induced immune thrombocytopenia and guide decisions about continued clopidogrel use or alternative treatment. The result should be reviewed by a clinician alongside bleeding symptoms, platelet counts, and other laboratory findings.

Short name

Clopidogrel-dependent platelet IgG

Frequently asked questions

Does a positive result mean clopidogrel is definitely causing my low platelets?
No. It supports a clopidogrel-related immune reaction, but other possible causes must also be evaluated.
Can this test show whether clopidogrel is working?
No. It detects possible drug-dependent antibodies and is not a test of clopidogrel's antiplatelet effectiveness.
What if the result is negative?
A clopidogrel-related immune reaction may still be possible, so the result should be interpreted with your symptoms, medication timing, and other tests.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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