PB1132 - Comparison of thrombophilia assay results for the ISTH/SSC Plasma Standard from different EQA providers – data from the EQATH group

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

IJ

Ian Jennings

Programme manager
UK NEQAS BC
Sheffield, England, United Kingdom

Co-Author(s)

Piet Meijer, PhD

Director
ECAT Foundation
Voorschoten, Zuid-Holland, Netherlands
JO

John Olson

Professor Emeritus
UT Health San Antonio
San Antonio, Texas, United States
RM

Richard A. Marlar

Professor, Department of Pathology
University of New Mexico
Albuquerque, New Mexico, United States
SA

Sandya Arunachalam

Scientist
RCPAQAP
St Leonards, New South Wales, Australia
NZ

Nicole Zantek

Medical Director
University of Minnesota
Minneapolis, Minnesota, United States
IW

Isobel Walker

Director
UK NEQAS BC
Sheffield, England, United Kingdom
Christopher Mark Peter Reilly-Stitt, MSc

Deputy Programme Manager
UK NEQAS BC
Sheffield, England, United Kingdom
ED

Elysse Dean

Scientist
RCPAQAP
St Leonards, New South Wales, Australia
Chantal Bon, PhD

Medical Biologist
ProBioQual Association
Lyon, Auvergne, France
RM

Roland Meley

Medical Biologist
ProBioQual Association
Lyon, Auvergne, France
Martine J. van Essen - Hollestelle, PhD

Scientist
ECAT Foundation
Voorschoten, Zuid-Holland, Netherlands
MK

Mareen Kutsch

MTLA
LMU Klinik der Universität München
Munchen, Bayern, Germany
MS

Michael Spannagl

Head of reference institution
LMU Klinik der Universität München
Munchen, Bayern, Germany
DU

David Unold

Associate Clinical Professor
UC Davis School of Medicine
Sacramento, California, United States
ES

Eric Salazar

Associate Professor
UT Health San Antonio
San Antonio, Texas, United States
KS

Kristi Smock

Department of Pathology and ARUP Laboratories
University of Utah
Salt Lake City, Utah, United States
EP

Elizabeth Plumhoff

MT(ASCP)
North American Specialized Coagulation Laboratory Association (NASCOLA)
Rochester, Minnesota, United States

Background: The EQATH group comprises providers of External Quality Assessment (EQA) in Thrombosis and Haemostasis, collaborating to improve EQA provision in this field. To explore the feasibility of pooling data for analysis of tests performed by very few centres worldwide an exercise was carried out using the ISTH SSC plasma standard for thrombophilia screening assays.

Aims: To assess data from centres in different EQA programmes testing the same sample.

Methods: 6 EQA providers took part in this exercise (see author list for affiliations). All providers distributed the SSC plasma standard as a ‘blinded’ sample to participants for thrombophilia screening tests; exercises were carried out between November 2020 – December 2021. Data were collected by each provider, anonymised, and pooled for analysis. Results were analysed as overall results from each EQA provider, and by kit/method-specific comparisons of data from all providers pooled together. For each parameter, median results and range were determined.

Results: Over 1250 sets of data were returned. Table 1 details the overall median results for all centres, and for comparison shows the relative assigned value for the SSC plasma standard (lot #5). The medians were within 4% of the assigned values for each parameter except for protein C activity by clot-based assay (EQATH median 8% higher). Overall median results obtained for each EQA provider data were very similar. Method specific differences were not evident with the exception of Werfen/HemosIL and Siemens free protein S assay results (median 99.0 vs 91.1 IU/dL, p< 0.001), Werfen/HemosIL and Siemens protein S activity results (median 80.0 vs 74.4 IU/dL, p< 0.0005) and Stago and Siemens protein S activity results (median 78.0 vs 74.4 IU/dL, p< 0.01).

Conclusion(s): A joint exercise amongst EQA providers allowed for pooled analysis of data and demonstrated consistent results between programmes. Further exercises for less widely performed assays are planned.