A new platelet activated-release test for monitoring aspirin response / 中华检验医学杂志

ABSTRACT

Objective To establish a new method for monitoring aspirin response by platelet activated-release experiment.Methods The platelets in whole blood were activated by ARA,and the MPC was measured by hematology analyzer.Blood samples were drawn from five healthy volunteers for measuring MPC,LTAARA and platelet membrane CD62P expression.Blood samples were mixed thoroughly right after venipuncture. The concentration of ARA (0,0. 5,1.0,1.5,5.0 and 10. 0 mmol/L) and the time for platelet activation (5,10,20,30,40,50,60,70,80 and 90 min in 37℃ water bathe) were optimized to evaluate the stability (0,1,2 and 3 h after venipuncture) and reproducibility (MPC, LTAARA and platelet membrane CD62p were measured ten times and the CV was calculated). Platelets were mixed with acetylsalicylic acid at different concentrations in vitro in order to verify the validity for monitoring aspirin response. The percentage of CD62p positive platelets after activated by ARA was measured using flow cytometer with CD61-PerCP and CD62p-PE antibodies. The correlation between MPC and CD62P was determined. 100 patients without taking or stop taking aspirin more than 7 days and 93 patients who took aspirin at least 7 days were enrolled. Duplicate measurements of platelet function were performed using the change of MPC (ARA 0. 5 mmol/L) and LTA (ARA 0. 5 mmol/L) among two patient groups to evaluate the accuracy of the new method. Results Platelcts were completely activated by ARA at final concentration of 0. 5 mmol/L. MPC negatively correlated with platelet membrane CD62p(r=-0. 755,P<0. O1 ). MPC was stable for 30 minutes in 37 ℃ water bathe after ARA activation. The result of MPC was consistent at room temperature within 3 hours after blood collection. This method had good reproducibility. CV in batch using fresh whole blood was 1.35% and CV between batches using commercial control whole blood were 0. 71% and 0. 74%. With the concentration of acetylsalicylic acid increased (0-6. 95 μmol/L), MPC increased as CD62P decreased, which showed negative correlation (r=-0. 765 ,P <0. 01 ). The difference of MPC before and after ARA activation (ΔMPC) and MPC variance ratio of the group taking aspirin were ( 8. 2±8. 6) g/L and ( 3.4±3.6) %, and they were (37.4±10. 3 ) g/L and ( 15.7±4.0) % in control group, respectively.ΔMPC and MPC variance ratio showed significant difference between the two groups ( t=21. 522, 22. 409, all P < 0. 01 ). Area under the ROC curve for MPC variance ratio was 0. 992 with sensitivity of 96. 8% and specificity of 99.0% for monitoring the aspirin response using the cut-off of 8. 7%. MPC variance ratio had good correlation with LTAARA (r = 0. 720, P < 0. O1 ). Conclusions A new method for monitoring aspirin response by platelet activated-release experiment is established. It may replace LTAARA for routine clinical examination.