Strategy for standardization of activated partial thromboplastin time and lupus anticoagulant

Yamazaki, Satoshi; Naito, Sumiyoshi; Shizuka, Reiko; Ieko, Masahiro

doi:10.2491/jjsth.27.636

Cited by 4 publications

(1 citation statement)

References 2 publications

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“…Conversely, reagent D had a higher sensitivity for unfractionated heparin than other reagents. 14 Our study also indicates that in cases showing a bp, the bp was observed with all four reagents, and there was no difference in its appearance; however, the bp was not observed in all cases of patients with HA, and was only observed in cases with highly prolonged APTT. For this reason, even though detection of the bp is useful as a diagnostic assistance in patients with HA, combining qualitative evaluation of the clot waveform and quantitative evaluation using the parameters is important to determine patients with HA showing mildly prolonged APTT.…”

Section: Discussionsupporting

confidence: 70%

Differences in the Composition of Activated Partial Thromboplastin Time (APTT) Reagents Affect Clot Waveform Analysis

et al. 2022

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Background Clot waveform analysis (CWA) based on activated partial thromboplastin time (APTT) is a useful assay for hemostasis. However, the effects of activators and phospholipid conditions on CWA have not been adequately investigated. Therefore, we characterized CWA using four different APTT reagents. Methods We used 39 archived plasma samples from patients with hemophilia A (HA), 16 samples from patients with HA under emicizumab treatment, and 10 samples from healthy individuals for CWA with four different types of APTT reagents (reagents A, B, C, and D). We then compared Ad|min1|, Ad|min2|, and Ad|max2| from the CWA, which reflect the maximum velocity, maximum acceleration, and maximum deceleration, respectively, among the four reagents. Results Similar clot waveform shapes were observed for each reagent in the healthy donor group, HA group, and HA under emicizumab group, and the waveform was different for each target group. Significant changes were found in clotting time (CT) (s), Ad|min1| (%/s), Ad|min2| (%/s 2 ), and Ad|max2| (%/s 2 ). The waveform pattern for the coagulation reaction by reagent D, comprising silica and synthetic phospholipids, was the slowest among the reagents examined. Further, the difference in Ad|min1| (%/s) and Ad|min2| (%/s 2 ) was larger than that in CT depending on the reagent used(s), indicating that the measured value of CWA was affected by the reagent composition. Conclusion Our results showed a significant difference among reagents with varying composition and concentration; this was found to affect the parameters obtained from CWA. Thus, the differences between reagents hinder standardization of quantitative evaluation using these parameters; further, this highlights the necessity of understanding the characteristics of APTT reagents and determining the reference range in individual facilities.

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Section: Discussionsupporting

confidence: 70%