Background Thrombotic thrombocytopenic purpura (TTP) is a rare but potentially fatal disorder caused by ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) deficiency. Prompt identification/exclusion of TTP can thus be facilitated by rapid ADAMTS13 testing. The most commonly utilized (enzyme‐linked immunosorbent assay [ELISA]–based) assay takes several hours to perform and so does not generally permit rapid testing. Objectives To evaluate the utility of a new automated test for ADAMTS13 activity, the HemosIL AcuStar ADAMTS13 Activity assay, based on chemiluminescence and able to be performed on an ACL AcuStar instrument within 33 minutes. Patients/Methods This multicenter (n = 8) assessment included testing of more than 700 test samples, with similar numbers of prospective (n = 348) and retrospective (n = 385) samples. The main comparator was the Technozym ADAMTS13 Activity ELISA. We also assessed comparative performance for detection of ADAMTS13 inhibitors using a Bethesda assay. Results Overall, the chemiluminescent assay yielded similar results to the comparator ELISA, albeit with slight negative bias. ADAMTS13 inhibitor detection was also comparable, albeit with slight positive bias with the AcuStar assay. Assay precision was similar with both assays, and we also verified assay normal reference ranges. Conclusions The HemosIL AcuStar ADAMTS13 Activity assay provided results rapidly, which were largely comparable with the Technozym ADAMTS13 Activity ELISA assay, albeit lower on average. Conversely, inhibitor levels tended to be identified at a higher level on average. Thus, the HemosIL AcuStar ADAMTS13 Activity assay provides a fast and accurate means to quantitate plasma levels of ADAMTS13 for TTP/ADAMTS13 identification/exclusion, and potentially also for other applications.

Objectives To verify a single platform of hemostasis instrumentation, the ACL TOP 50 Family, comprising 350, 550, and 750 instruments, across a large network of 60 laboratories. Methods Comparative evaluations of instrument classes (350 vs 550 and 750) were performed using a large battery of test samples for routine coagulation tests, comprising prothrombin time/international normalized ratio, activated partial thromboplastin time (APTT), thrombin time, fibrinogen and D-dimer, and using HemosIL reagents. Comparisons were also made against existing equipment (Diagnostica Stago Satellite, Compact, and STA-R Evolution) and existing reagents to satisfy national accreditation standards. Verification of manufacturer normal reference ranges (NRRs) and generation of an APTT heparin therapeutic range were undertaken. Results The three instrument types were verified as a single instrument class, which will permit standardization of methods and NRRs across all instruments (n = 75) to be deployed in 60 laboratories. In particular, ACL TOP 350 test result data were similar to ACL TOP 550 and 750 and showed no to limited bias. All manufacturer NRRs were verified with occasional minor variance. Conclusions This ACL TOP 50 Family (350, 550, and 750) verification will enable harmonization of routine coagulation across all laboratories in the largest public pathology network in Australia.

Most studies on the sensitivities of coagulation assays to direct oral anticoagulants (DOACs) are based on normal plasma spiked with anticoagulant in the laboratory. Recent studies have shown that reagent sensitivity varies significantly depending on whether spiked or patient samples are used. The aim of this study was to compare the sensitivities of routine coagulation assays in patient samples and commercial drug specific calibrators using commonly used activated partial thromboplastin time (APTT) and prothrombin time (PT) reagents (i.e., Actin FS and Neoplastine CI Plus for APTT and PT, respectively) in Australian laboratories. Samples collected at Pathology North Hunter (PN-H) for dabigatran (n=39), rivaroxaban, (n=56) or apixaban levels (n=22) between February 2013 and November 2015 were analysed and compared to two different commercial drug specific calibrators from different manufacturers for each DOAC. Our results show that dabigatran (Hyphen and Technoclone) and rivaroxaban (Stago) calibrators tend to overestimate the APTT but are similar to patient samples for PT. A cut-off DOAC level of 50 ng/mL based on results from patient samples within the laboratory can be used as the lower limit which will result in prolongation of APTT for dabigatran (sensitivity 96%, n=25) and PT for rivaroxaban (sensitivity 97%, n=29), respectively. Individual laboratories should be familiar with the sensitivity of their coagulation reagents to different DOACs including differences between patient samples versus different commercial drug specific calibrators.

Objectives Thrombophilia testing is commonly performed within hemostasis laboratories, and the ACL TOP 50 family of instruments represent a new ‘single platform’ of hemostasis instrumentation. The study objective was to evaluate these instruments and manufacturer reagents for utility of congenital thrombophilia assays. Methods Comparative evaluations of various congenital thrombophilia assays (protein C [PC], protein S [PS], antithrombin [AT], activated protein C resistance [APCR]) using newly installed ACL TOPs 550 and 750 as well as comparative assessments with existing, predominantly STAGO, instrumentation and reagents. Verification of manufacturer assay normal reference ranges (NRRs). Results HemosIL PC and free PS assays showed good comparability with existing Stago methods (R>0.9) and could be considered as verified as fit for purpose. HemosIL AT showed high relative bias with samples from patients on direct anti-Xa agents, compromising utility. Manufacturer NRRs for PC, PS and AT were verified with minor variance. Given the interference with direct anti-Xa agents, an alternate assay (Hyphen) was evaluated for AT, and the NRR also verified. The HemosIL Factor V Leiden (APC Resistance V) evidenced relatively poor performance compared to existing assays, and could not be adopted for use in our network. Conclusions This evaluation of HemosIL reagents on ACL TOP 50 Family instruments identified overall acceptable performance of only two (PC, free PS) of four thrombophilia assays, requiring use of third-party reagents on ACL instruments for the other two assays (AT, APCR).