Lupus anticoagulant laboratory diagnosis by applying the 2020 ISTH-SSC guidelines.
Antiphospholipid syndrome
Clinical laboratory techniques
Cut-off values
Lupus coagulation inhibitor
Thrombosis
Journal
Thrombosis research
ISSN: 1879-2472
Titre abrégé: Thromb Res
Pays: United States
ID NLM: 0326377
Informations de publication
Date de publication:
04 2023
04 2023
Historique:
received:
07
11
2022
revised:
10
02
2023
accepted:
14
02
2023
pubmed:
25
2
2023
medline:
21
3
2023
entrez:
24
2
2023
Statut:
ppublish
Résumé
The ISTH-SSC guidelines for lupus anticoagulant (LA) testing recommend using in-house determined cut-off values, pooled normal plasma (PNP) for ratio normalization, and a ratio for the mixing test interpretation. They strongly support the mixing step role in the diagnostic process. To investigate and compare the LA testing results and interpretations obtained following the ISTH-SSC guidelines or the available alternatives. Blood samples for LA testing from 462 consecutive patients were evaluated for screening, mixing and confirmatory tests. The analysis focused on the interpretation differences between using (1) the in-house cut-off values versus the manufacturer's cut-off values, (2) a normalized ratio calculated using PNP at each run versus the mean of the reference interval, (3) a normalized ratio versus the index of circulating anticoagulant to interpret the mixing step, and (4) a two-step versus three-step procedure. LA testing outcomes were comparable when using the in-house and manufacturer's cut-off values. More positive dilute Russell's viper venom (DRVV) time results were obtained with the normalized ratio based on PNP than with the mean of the reference interval. Overall, the mixing test results obtained with the normalized ratio and the index of circulating anticoagulant showed a good agreement. Among the 97 DRVV Screen test-positive samples, 33 and 89 were classified as LA-positive with the 3-step and the 2-step procedure, respectively. The cut-off value used and the way to normalize ratios had a limited impact. Conversely, it is important to understand the mixing test characteristics to maximize its diagnostic potential.
Sections du résumé
BACKGROUND
The ISTH-SSC guidelines for lupus anticoagulant (LA) testing recommend using in-house determined cut-off values, pooled normal plasma (PNP) for ratio normalization, and a ratio for the mixing test interpretation. They strongly support the mixing step role in the diagnostic process.
OBJECTIVES
To investigate and compare the LA testing results and interpretations obtained following the ISTH-SSC guidelines or the available alternatives.
PATIENTS/METHODS
Blood samples for LA testing from 462 consecutive patients were evaluated for screening, mixing and confirmatory tests. The analysis focused on the interpretation differences between using (1) the in-house cut-off values versus the manufacturer's cut-off values, (2) a normalized ratio calculated using PNP at each run versus the mean of the reference interval, (3) a normalized ratio versus the index of circulating anticoagulant to interpret the mixing step, and (4) a two-step versus three-step procedure.
RESULTS
LA testing outcomes were comparable when using the in-house and manufacturer's cut-off values. More positive dilute Russell's viper venom (DRVV) time results were obtained with the normalized ratio based on PNP than with the mean of the reference interval. Overall, the mixing test results obtained with the normalized ratio and the index of circulating anticoagulant showed a good agreement. Among the 97 DRVV Screen test-positive samples, 33 and 89 were classified as LA-positive with the 3-step and the 2-step procedure, respectively.
CONCLUSIONS
The cut-off value used and the way to normalize ratios had a limited impact. Conversely, it is important to understand the mixing test characteristics to maximize its diagnostic potential.
Identifiants
pubmed: 36827954
pii: S0049-3848(23)00048-8
doi: 10.1016/j.thromres.2023.02.009
pii:
doi:
Substances chimiques
Lupus Coagulation Inhibitor
0
Anticoagulants
0
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
38-45Informations de copyright
Copyright © 2023 Elsevier Ltd. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.