Comparison of real world and core laboratory lupus anticoagulant results from the Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking (APS ACTION) clinical database and repository.

Abstract

BACKGROUND:

Variability remains a challenge in lupus anticoagulant (LA) testing.

OBJECTIVE:

To validate LA test performance between Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking (APS ACTION) Core laboratories and examine agreement in LA status between Core and local/hospital laboratories contributing patients to this prospective registry.

METHODS:

Five Core laboratories used the same reagents, analyzer type, protocols, and characterized samples for LA validation. Non-anticoagulated registry samples were retested at the corresponding regional Core laboratories and anticoagulated samples at a single Core laboratory. Categorical agreement and discrepancies in LA status between Core and local/hospital laboratories were analyzed.

RESULTS:

Clotting times for the reference/characterized plasmas used for normalized ratios were similar between Core laboratories (CV <4%); precision and agreement for LA positive/negative plasma were similar (all CV ≤5%) in the four laboratories that completed both parts of the validation exercise; 418 registry samples underwent LA testing. Agreement for LA positive/negative status between Core and local/hospital laboratories was observed in 87% (115/132) non-anticoagulated and 77% (183/237) anticoagulated samples. However, 28.7% (120/418) of samples showed discordance between the Core and local/hospital laboratories or equivocal LA results. Some of the results of the local/hospital laboratories might have been unreliable in 24.7% (41/166) and 23% (58/252) of the total non-anticoagulated and anticoagulated samples, respectively. Equivocal results by the Core laboratory might have also contributed to discordance.

CONCLUSIONS:

Laboratories can achieve good agreement in LA performance by use of the same reagents, analyzer type, and protocols. The standardized Core laboratory results underpin accurate interpretation of APS ACTION clinical data.

• Authors: Maria Efthymiou, Ian J Mackie, Philip J Lane, Danieli Andrade, Rohan Willis, Doruk Erkan, Savino Sciascia, Steven Krillis, Elisa Bison, Margarete Borges Galhardo Vendramini, Zurina Romay-Penabad, Miao Qi, Maria Tektonidou, Amaia Ugarte, Cecilia Chighizola, H Michael Belmont, Maria Angeles Aguirre, Lanlan Ji, D Ware Branch, Guilherme de Jesus, Paul R Fortin, Laura Andreoli, Michelle Petri, Ricard Cervera, Esther Rodriguez, Jason S Knight, Tatsuya Atsumi, Joann Vega, Ecem Sevim, Maria Laura Bertolaccini, Vittorio Pengo, Hannah Cohen, APS ACTION
• Journal: Journal of thrombosis and haemostasis : JTH (J Thromb Haemost) Vol. 17 Issue 12 Pg. 2069-2080 (12 2019) ISSN: 1538-7836 [Electronic] England
• PMID: 31364274 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Validation Study)
• Copyright: © 2019 International Society on Thrombosis and Haemostasis.

Chemical References

• Anticoagulants
• Biomarkers
• Lupus Coagulation Inhibitor

Topics

• Anticoagulants (blood)
• Antiphospholipid Syndrome (blood, diagnosis)
• Biomarkers (blood)
• Clinical Trials as Topic
• Databases, Factual
• Humans
• Laboratory Proficiency Testing
• Lupus Coagulation Inhibitor (blood)
• Observer Variation
• Predictive Value of Tests
• Prospective Studies
• Prothrombin Time (standards)
• Registries
• Reproducibility of Results
• Serologic Tests (standards)