Comparison between a new platelet count drop method PL-11, light transmission aggregometry, VerifyNow aspirin system and thromboelastography for monitoring short-term aspirin effects in healthy individuals

Abstract

Platelet function has been described by many laboratory assays, and PL-11 is a new point-of-care platelet function analyzer based on platelet count drop method, which counts platelet before and after the addition of agonists in the citrated whole blood samples. The present study sought to compare PL-11 with other three major more established assays, light transmission aggregometry (LTA), VerifyNow™ aspirin system and thromboelastography (TEG), for monitoring the short-term aspirin responses in healthy individuals. Ten healthy young men took 100 mg/d aspirin for 3-day treatment. Platelet function was measured via PL-11, LTA, VerifyNow and TEG, respectively. The blood samples were collected at baseline, 2 hour, 1 day during the aspirin treatment and 1 day, 5 ± 1 days, 8 ± 1 days after the aspirin withdrawal. Moreover, 90 additional healthy subjects were recruited to establish a reference range for PL-11. Platelet function of healthy subjects decreased significantly 2 hours after 100 mg/d aspirin intake and began to recover during 4-6 days after the aspirin withdrawal. Correlations between methods were PL-11 vs. LTA (r = 0.614, p < 0.01); PL-11 vs. VerifyNow (r = 0.829, p < 0.01); PL-11 vs. TEG (r = 0.697, p < 0.001). There was no significant bias between PL-11 and LTA at baseline (bias = 1.94%, p = 0.804) using Bland-Altman analysis, while the data of PL-11 were significantly higher than LTA (bias = 24.02%, p < 0.001) during the aspirin therapy. The reference range for PL-11 in healthy young individuals was from 66.8 to 90.5% (95%CI). When aspirin low-responsiveness was defined as LTA > 20%, the cut-off values for each method were, respectively: PL-11 > 50%, VerifyNow > 533 ARU, TEG > 60.2%. The results of different platelet function assays were uninterchangeable for monitoring aspirin response and correlations among them were also varied. Correlations among PL-11 and other three major assays suggested the ability of PL-11 to assess the treatment effects of aspirin. But a large cohort study is needed to confirm the cut-off value of aspirin response detected by PL-11.

An in-vitro evaluation of direct thrombin inhibitor and factor Xa inhibitor on tissue factor-induced thrombin generation and platelet aggregation

“…In the one hand, thrombin generation was directly measured via newly developed calibrated automated thrombogram method rather than indirectly evaluated by thrombin-antithrombin complex and prothrombin fragment 1 þ 2 [17]. On the other hand, the modified automated impedance technique based on the whole blood simplified the detecting process of PAg and time-saved [11]. Additionally, unlike previous study [14], about 4 min initial delay of TF-induced PAg was observed in novel anticoagulants pretreated whole blood, which was consistent with the Lagtime in plasmatic thrombin generation.…”

“…PAg was evaluated by a kinetic counting method via PL-11 platelet analyzer (SINNOWA, Nanjing, China) based on an automated impedance technique [11]. In brief, a 288-ml citrated blood sample was transferred into a polycarbonate tube, mixed with 12 ml of increasing concentrations of dabigatran, rivaroxaban or vehicles, and incubated at 378C for 5 min.…”

High platelet reactivity affects the clinical outcomes of patients undergoing percutaneous coronary intervention

“…Therefore, platelet function assays were not equally interchangeable and the correlations among them were varied. PL-11 by “sequentially platelet counting method” gives more exact and stable results of platelet counting before and after the addition of agonists in the citrated whole blood samples, which has been demonstrated to be correlated with LTA and VerifyNow [11]. Consequently, sequentially platelet counting method by PL-11 would bean optional device for platelet function tests.…”

“…PL-11 analyzer (SINNOWA Co., Nanjing, China) was used for the test [11, 12]. With standardized and easier test method, the analyzer gives more exact and stable results of platelet maximum aggregation ratio (MAR%).…”

“…Moreover, the VerifyNow P2Y12 assay was widely used in these studies, which has been reported to be nonflexible, very expensive, limited hematocrit and platelet count, and just moderate agreement with other platelet function tests [9, 10]. However, sequentially platelet counting method by PL-11 (SINNOWA Co., Nanjing, China) was a novel analyzer for platelet reactivity test by automatic impedance technique [11]. Therefore, this prospective study was designed to assess the association between platelet reactivity with the novel automatic platelet aggregometer and stent thrombosis among patients with DES implantation.…”