PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 10968906

Conceptions and misconceptions in testing for lupus anticoagulants.

T Exner
View original source ↗Export metadata ↓

Abstract

The aim of the following presentation is to review certain technical issues complicating clotting tests for lupus anticoagulants (LA). This is a field riddled with incorrect and misleading studies which often make progress difficult and which are difficult to retract. Inconsistent test sensitivity comparisons are sometimes due to incorrect methods being used but are more often due to contamination with platelets and instrument effects. Time dependence of LA is often due to pH drift during incubation and probably all LA are immediate acting (at least in our hands). The use of platelets in confirmatory tests is dangerous and can lead to false-positive results in patients with anti-factor V and heparin-like inhibitors.

Explore related subjects

Blood Coagulation TestsHumansLupus Coagulation InhibitorSensitivity and SpecificityJournal ArticleReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

T Exner. 2000. Conceptions and misconceptions in testing for lupus anticoagulants.. https://doi.org/10.1006/jaut.2000.0392

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

In vitro kinetics of factor VIII activity in patients with mild haemophilia A and a discrepancy between one-stage and two-stage factor VIII assay results.

In some mild haemophilia A patients (discrepant haemophilia), factor VIII coagulant activity (FVIII:C) levels, by one-stage assay are more than double than those by two-stage assay. This may be due to the longer incubation times (10-12 min) in the two-stage assay. This study aimed to determine the time course of the activation phase of the two-stage assay, using both classical coagulation and chromogenic detection methods. In both systems, for equivalent patients (equivalent FVIII:C levels by one-stage and two-stage assays, n = 6, all different mutations), similar FVIII:C results were obtained with short- or long-incubation times. In contrast, plasma from discrepant patients (n = 8, five different mutations) showed higher FVIII:C at shorter incubation times than after longer incubation times. In the chromogenic assay, FVIII:C levels were higher after incubation for 2 min (23-56%, mean 41%) than after 10 min (19-41%, mean 29%). In the classical coagulation assay, FVIII:C levels were higher at shorter incubation times (21-64%, mean 37%) than with the longer incubation times usually used (13-29%, mean 23%). These time-course experiments have verified that the longer incubation time used in the two-stage assay is at least partly responsible for the lower FVIII:C measured by that assay in discrepant haemophilia.

Blood Coagulation Tests↗
PubMed2007

Von Willebrand disease within the collective of haemophilic patients as reason for unexpected bleeding episodes.

In the treatment of haemophilia A and B, recombinant coagulation factors are increasingly replacing plasma-derived factor VIII and IX concentrates. Although provided with replacement therapy, individual patients may exhibit bleeding episodes, which are difficult to control. These bleeds may be caused by von Willebrand disease (VWD) as an additional underlying coagulation disorder. We report in the present study our experience that in the collective of haemophilic patients, VWD must be anticipated at least with the same order of magnitude as it appears in a normal healthy population. Among the patients at our treatment centre, two patients (1.5%) were identified as suffering from VWD in addition to haemophilia A. In the collective of haemophilia B patients at our centre, three patients (10%) with VWD were found. Two of these patients exhibited unexpected severe bleeding episodes, which could only satisfactorily be controlled by the administration of Haemate-P or DDAVP supplementary to the recombinant coagulation factor concentrate.

Blood Coagulation Tests↗