PB0081 - Evaluation of a new Stago system sthemO dRVV screen and confirm on sthemO 301 coagulation analyzer for lupus anticoagulant detection

Sunday, June 23, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Co-Author(s)

SL

Sylvain Lamoine

Research ingineer
CHU Clermont-Ferrand, Service d'hématologie biologique
Clermont-Ferrand, Auvergne, France
SG

Stéphanie Guerin

Technician
CHU Clermont Ferrand, Service d’Hématologie Biologique
Clermont-Ferrand, Auvergne, France
MT

Maxence Tillier

Technician
CHU Clermont Ferrand, Service d’Hématologie Biologique
Clermont-Ferrand, Auvergne, France
AT

Alexandre Trapani

Technician
CHU Clermont-Ferrand, Service d’Hématologie Biologique
Clermont-Ferrand, Auvergne, France
AT

Adeline Trayaud

Technician
CHU Clermont-Ferrand, Service d’Hématologie Biologique
Clermont-Ferrand, Auvergne, France
RD

Romain Duriez

Laboratory coordinator
Cerba Xpert
Lille, Nord-Pas-de-Calais, France
FL

Françoise Leboulaire

Project manager
Cerba Xpert
Lille, Nord-Pas-de-Calais, France
Joffrey Feriel, PharmD

Scientific manager
Diagnostica Stago
Asnières sur Seine, Ile-de-France, France

Presenting Author(s)

Aurélien Lebreton, MD,PhD

MD
Service d’hématologie, CHU Clermont-Ferrand, Hôpital Estaing, France
Clermont Ferrand, Auvergne, France

Background: Lupus anticoagulant (LA) is one of the laboratory criteria for the identification of APS (AntiPhospholipid Syndrome). Its main characteristic is its ability to prolong phospholipid-dependent clotting time. According to ISTH recommendations, two tests should be performed, a dRVVT (dilute Russel Viper Venom Time) and a sensitive aPTT. The combination of these two tests has been proven to have high detection rates of LA.

Aims: The aim of the study was to determine the reference intervals and cut-off ratios for the sthemO dRVV screen and confirm and to validate their performances for LA detection.

Methods: 120 healthy subjects were used for the reference intervals determination (2.5 – 97.5 percentiles). Cut-off values were determined using the 99th percentile according to ISTH guidelines. The population for method comparison consisted in lupus patients, AntiPhospholipid Syndrome, autoimmune disease and anticoagulant treatments. Quality controls (QCs) have been measured before and after each run.

Results: All QCs were within their expected ranges. The Reference Intervals obtained for sthemO dRVV screen M, screen L and confirm were respectively [31.3 – 45.8 sec], [32.4 – 48.5 sec] and [32.4 – 40.1 sec]. With a cut-off value of 1.20, the overall agreement reach 96% and 92% for the sthemO dRVV screen M and the sthemO dRVV screen L when compared to its predicate (Table1).
The sthemO Pool Norm showed an agreement of 98% when compared to its predicate reagent CRYOcheck™ (Table2) using sthemO dRVV screen M, screen L and confirm.

Conclusion(s): We defined the Reference Intervals for each reagent as well as cut-off values defined at 1.20 for the screen ratio and the normalized ratio. The sthemO dRVV screen and confirm with sthemO Pool Norm on sthemO 301 are validated for their intended purpose. The sthemO Pool Norm is equivalent to its predicate CRYOcheck™.