Platelet Activation Markers (beta-thromboglobulin and platelet factor 4) and Clopidogrel Drug Response in Patients with Myocardiac Infarction

BACKGROUND: Dual antiplatelet therapy (aspirin and clopidogrel) is used to prevent adverse cardiac events in patients undergoing percutaneous coronary intervention (PCI). Some patients do not respond adequately to clopidogrel. Beta-thromboglobulin (beta-TG) and platelet factor 4 (PF-4) can act as markers to detect platelet activation. We investigated the relationship between clopidogrel response and the dynamics of beta-TG and PF4 concentrations. METHODS: This study included 36 myocardial infarction (MI) patients, who underwent PCI and was indicated for dual antiplatelet therapy. Platelet reactivity, using the VerifyNow P2Y12 assay, was measured on the 3rd day of PCI. At the time of admission, and on the 3rd and 10th day of PCI, the plasma beta-TG and PF4 concentrations were quantified. RESULTS: Ten patients (27.8%) were clopidogrel non-responders displaying >208 P2Y12 reaction units. At the time of admission, levels of beta-TG in patients were elevated than that in the healthy controls (P<0.001). A similar trend was observed on the 3rd and 10th day of PCI (P<0.001). The beta-TG levels on the 10th day were reduced than those at the time of admission and on the 3rd day of PCI. PF4 levels were not different between patients and controls, and were not significantly reduced after PCI. Higher beta-TG levels were observed in clopidogrel non-responders on the 10th day, but not significant. CONCLUSIONS: Clopidogrel therapy in MI reduce beta-TG concentration, but the beta-TG and PF4 levels before and after therapy are not associated with the response to clopidogrel. Platelet-derived markers may not be suitable for distinguishing clopidogrel non-responders.

Evaluation of IH-1000 for Automated ABO-Rh Typing and Irregular Antibody Screening / 대한수혈학회지

BACKGROUND: Despite modern advances in laboratory automated medicine, work-process in the blood bank is still handled manually. Several automated immunohematological instruments have been developed and are available in the market. The IH-1000 (Bio-Rad Laboratories, Hercules, CA, USA), a fully automated instrument for immunohematology, was recently introduced. In this study, we evaluated the performance of the IH-1000 for ABO/Rh typing and irregular antibody screening. METHODS: In October 2011, a total of 373 blood samples for ABO/Rh typing and 303 cases for unexpected antibody screening were collected. The IH-1000 was compared to the manual tube and slide methods for ABO/Rh typing and to the microcolumn agglutination method (DiaMed-ID system) for antibody screening. RESULTS: For ABO/Rh typing, concordance rate was 100%. For unexpected antibody screening, positive results for both column agglutination and IH-1000 were observed in 10 cases (four cases of anti-E and c, three of anti-E, one of anti-D, one of anti-M, and one of anti-Xg) and negative results for both were observed in 289 cases. The concordance rate between IH-1000 and column agglutination was 98.7%. Sensitivity and specificity were 90.9% and 99.3%, respectively. CONCLUSION: The automated IH-1000 showed good correlation with the manual tube and slide methods and the microcolumn agglutination method for ABO-RhD typing and irregular antibody screening. The IH-1000 can be used for routine pre-transfusion testing in the blood bank.