Platform
Company
Complete Blood Count
Review status
Currently under review
Pending specialist review and validation.
This test checks how well your platelets clump together when they are stimulated by collagen, a natural trigger of platelet activation. The measurement is performed with optical aggregometry, a method that shines light through your platelet-rich plasma and tracks changes as platelets aggregate.
It is one part of a broader platelet function panel. The test looks at function, not the number of platelets. Results help your care team see whether your platelets respond appropriately to collagen compared with their behavior to other common agonists used in the lab.
Doctors use collagen-induced platelet aggregation testing when you have symptoms that suggest a bleeding tendency, such as easy bruising, nosebleeds, heavy menstrual bleeding, or prolonged bleeding after procedures. It is also used before surgery in selected cases, or to help investigate suspected inherited or acquired platelet function disorders.
This test can show whether medicines that affect platelets, especially those that influence the cyclooxygenase pathway like aspirin, are dampening your platelet response. It can also point toward specific functional defects involving collagen receptors or platelet granule release. Interpreting this result typically involves looking at your responses to several different agonists, your medication history, and your clinical story.
A typical result suggests that your platelets respond as expected to collagen and can form a stable plug when needed. A weaker than expected response can occur with certain medications, including common pain relievers, or with specific platelet function conditions. A very poor response across several agonists may indicate a broader platelet function issue that your clinician will evaluate alongside your history and other laboratory findings.
Because platelet function testing is sensitive to sample handling and physiologic conditions, unexpected results are often confirmed by repeat testing or compared with results using other agonists. Your clinician may adjust medications, review timing of your last doses, or order additional tests to clarify the cause and guide safe plans for procedures or treatment.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
Aspirin, nonsteroidal anti-inflammatory drugs, some antidepressants, and certain antibiotics can blunt platelet responses to collagen. Fish oil, ginkgo, garlic, and other supplements may also affect platelet function. Always tell your care team everything you take.
Recent ingestion of platelet-affecting drugs can temporarily lower aggregation. Your clinician may advise a hold period before testing so the result reflects your baseline function rather than a recent dose.
Platelet-rich plasma must be prepared and tested promptly at controlled temperature. Delays, vigorous transport, hemolysis, or improper centrifugation can artifactually reduce or increase measured aggregation.
Very low platelet counts, marked anemia, or high hematocrit can alter light transmission and affect the optical signal. Laboratories often adjust platelet-rich plasma to a target range to minimize these effects.
Fever, infection, major stress, or recent surgery can temporarily change platelet reactivity. If you are acutely ill, your clinician may defer testing or interpret results with caution.
Physiologic changes in pregnancy and age-related differences can influence platelet behavior. Your clinician will consider these factors when interpreting results.
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