Original scientific paper

https://doi.org/10.11613/BM.2017.030705

Testing lupus anticoagulants in a real-life scenario - a retrospective cohort study

Franz Ratzinger ; Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
Tanja Panic ; Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
Helmuth Haslacher ; Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
Thomas Perkmann ; Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
Klaus G. Schmetterer ; Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
Sabine Belik ; Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
Georg Maenner ; Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
Ingrid Pabinger ; Clinical Division of Hematology and Hemostaseology, Department of Medicine I, Comprehensive Cancer Center Vienna, Medical University of Vienna, Vienna, Austria
Peter Quehenberger ; Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria

Abstract

Introduction: Lupus anticoagulant (LAC) testing is challenging. Most data are derived from a well-controlled study environment with potential
alterations to daily routines. The aim of this retrospective cohort study was to assess the capacity of various LAC screening tests and derived mixing
tests to predict a positive result in subsequent confirmation tests in a large cohort of patients.
Materials and methods: In 5832 individuals, we retrospectively evaluated the accuracy of the aPTT-A, aPTT-LAscreen, aPTT-FS and dRVVTscreen
and of their derived mixing tests in detecting a positive confirmation test result within the same blood specimen. The group differences, degree of
correlation and the predictive accuracy of LAC coagulation tests were analysed using the Mann-Whitney U test, the Spearman-rank-correlation and
by area under the receiver operating characteristic curve (ROC-AUC) analysis. ROC-AUCs were compared with the Venkatraman´s permutation test.
Results: The pre-test probability of patients with clinically suspected LAC was 36% in patients without factor deficiency or anticoagulation therapy.
The aPTT-LAscreen showed the best diagnostic accuracy with a ROC-AUC of 0.84 (95% CI: 0.82 – 0.86). No clear advantage of the dRVVT-derived
mixing test was detectable when compared to the dRVVTscreen (P = 0.829). Usage of the index of circulating anticoagulant (ICA) did not improve the
diagnostic power of respective mixing tests.
Conclusions: Among the parameters evaluated, aPTT-LAscreen and derived mixing test parameters were the most accurate tests. In our study cohort,
neither other mixing test nor the ICA presented any further advantage in LAC diagnostics.

Keywords

blood coagulation; blood coagulation tests; lupus coagulation inhibitor; partial thromboplastin time

Hrčak ID:

187588

URI

https://hrcak.srce.hr/187588

Publication date:

15.10.2017.

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