Multiple electrode aggregometry

Multiplate Analyzer

Multiple Electrode Aggregometry (MEA) is a method used in hematology to assess platelet function. This technique is instrumental in diagnosing various platelet disorders, monitoring antiplatelet therapy, and evaluating hemostasis in clinical and research settings. MEA is based on the principle of electrical impedance, measuring the change in resistance as platelets aggregate on electrodes in response to specific agonists.

Overview

Multiple Electrode Aggregometry involves the use of a specialized device that contains multiple electrodes within a cuvette where whole blood or platelet-rich plasma (PRP) is tested. When agonists such as ADP, collagen, thrombin receptor-activating peptide (TRAP), or arachidonic acid are added, platelets in the sample activate and aggregate. This aggregation leads to an increase in electrical impedance across the electrodes, which is measured and recorded. The results are indicative of the platelet function and are presented as aggregation curves, from which various parameters can be derived.

Clinical Applications

MEA is utilized in several clinical scenarios, including:

• Diagnosis of Platelet Function Disorders: MEA can help identify inherited or acquired disorders affecting platelet function, such as Glanzmann's Thrombasthenia or Bernard-Soulier syndrome.
• Monitoring Antiplatelet Therapy: Patients on antiplatelet medications like aspirin or P2Y12 inhibitors (e.g., clopidogrel) can be monitored using MEA to assess the efficacy of treatment and adjust dosages accordingly.
• Perioperative Management: In surgical settings, especially in patients undergoing cardiac surgery or those with a history of bleeding disorders, MEA can guide transfusion decisions and antiplatelet therapy management.
• Research: MEA is also a valuable tool in research studies investigating platelet function, hemostasis, and thrombosis.

Advantages and Limitations

Advantages:

• Provides rapid, real-time assessment of platelet function.
• Capable of testing the effect of multiple agonists simultaneously.
• Requires a relatively small volume of blood.

Limitations:

• Equipment and test costs can be high.
• Interpretation of results requires specialized knowledge and experience.
• Less standardized compared to other platelet function tests, leading to potential variability between laboratories.

Procedure

The MEA test procedure involves collecting a blood sample, typically via venipuncture, and anticoagulating it with sodium citrate. The sample is then placed in the MEA device, and specific agonists are added to separate cuvettes to initiate platelet aggregation. The change in impedance as platelets aggregate on the electrodes is measured over time, and the results are analyzed to assess platelet function.

Conclusion

Multiple Electrode Aggregometry is a sophisticated tool for evaluating platelet function, offering valuable insights in various clinical and research contexts. Despite its limitations, MEA's ability to provide rapid and detailed analysis of platelet aggregation makes it an important component of hemostatic assessment in modern medicine.