C Caron1, R Meley2, V Le Cam Duchez3, M F Aillaud4, C Lavenu-Bombled5, F Dutrillaux6, C Flaujac7, A Ryman8, C Ternisien9, D Lasne10, H Galinat11, C Pouplard12. 1. Laboratoire d'Hématologie-Hémostase, CHU Lille, Lille, France. 2. Laboratoire d'Hématologie-Hémostase, CHU Saint-Etienne, Saint-Etienne, France. 3. Laboratoire d'Hématologie-Hémostase, CHU Rouen, Rouen, France. 4. Laboratoire d'Hématologie-Hémostase, CHU Marseille, Marseille, France. 5. Laboratoire d'Hématologie-Hémostase, CHU Le Kremlin-Bicêtre, Le Kremlin-Bicêtre, France. 6. Laboratoire d'Hématologie-Hémostase, CHU Dijon, Dijon, France. 7. Laboratoire d'Hématologie-Hémostase, CHU Paris Cochin, Paris, France. 8. Laboratoire d'Hématologie-Hémostase, CHU Bordeaux, Bordeaux, France. 9. Laboratoire d'Hématologie-Hémostase, CHU Nantes, Nantes, France. 10. Laboratoire d'Hématologie-Hémostase, CHU Paris-Necker, Paris, France. 11. Laboratoire d'Hématologie-Hémostase, CHU Brest, Brest, France. 12. Laboratoire d'Hématologie-Hémostase, CHU Tours, Tours, France.
Abstract
INTRODUCTION: Factor XIII (FXIII) deficiency is a rare hemorrhagic disorder whose early diagnosis is crucial for appropriate treatment and prophylactic supplementation in cases of severe deficiency. International guidelines recommend a quantitative FXIII activity assay as first-line screening test. FXIII antigen measurement may be performed to establish the subtype of FXIII deficiency (FXIIID) when activity is decreased. METHODS: The aim of this multicenter study was to evaluate the analytical and diagnostic levels of performance of a new latex immunoassay, K-Assay® FXIII reagent from Stago, for first-line measurement of FXIII antigen. Results were compared to those obtained with the Berichrom® FXIII chromogenic assay for measurement of FXIII activity. Of the 147 patient plasma samples, 138 were selected for analysis. RESULTS: The accuracy was very good, with intercenter reproducibility close to 7%. Five groups were defined on FXIII activity level (<5% (n = 5), 5%-30% (n = 23), 30%-60% (n = 17), 60%-120% (n = 69), above 120% (n = 24)), without statistical differences between activity and antigen levels (P value >0.05). Correlation of the K-Assay® with the Berichrom® FXIII activity results was excellent (r = 0.919). Good agreement was established by the Bland and Altman method, with a bias of +9.4% on all samples, and of -1.4% for FXIII levels lower than 30%. One patient with afibrinogenemia showed low levels of Berichrom® FXIII activity but normal antigen level and clot solubility as expected. CONCLUSIONS: The measurement of FXIII antigen using the K-Assay® is a reliable first-line tool for detection of FXIII deficiency when an activity assay is not available.
INTRODUCTION: Factor XIII (FXIII) deficiency is a rare hemorrhagic disorder whose early diagnosis is crucial for appropriate treatment and prophylactic supplementation in cases of severe deficiency. International guidelines recommend a quantitative FXIII activity assay as first-line screening test. FXIII antigen measurement may be performed to establish the subtype of FXIII deficiency (FXIIID) when activity is decreased. METHODS: The aim of this multicenter study was to evaluate the analytical and diagnostic levels of performance of a new latex immunoassay, K-Assay® FXIII reagent from Stago, for first-line measurement of FXIII antigen. Results were compared to those obtained with the Berichrom® FXIII chromogenic assay for measurement of FXIII activity. Of the 147 patient plasma samples, 138 were selected for analysis. RESULTS: The accuracy was very good, with intercenter reproducibility close to 7%. Five groups were defined on FXIII activity level (<5% (n = 5), 5%-30% (n = 23), 30%-60% (n = 17), 60%-120% (n = 69), above 120% (n = 24)), without statistical differences between activity and antigen levels (P value >0.05). Correlation of the K-Assay® with the Berichrom® FXIII activity results was excellent (r = 0.919). Good agreement was established by the Bland and Altman method, with a bias of +9.4% on all samples, and of -1.4% for FXIII levels lower than 30%. One patient with afibrinogenemia showed low levels of Berichrom® FXIII activity but normal antigen level and clot solubility as expected. CONCLUSIONS: The measurement of FXIII antigen using the K-Assay® is a reliable first-line tool for detection of FXIII deficiency when an activity assay is not available.
Authors: Martina Leitner; Christian Büchold; Ralf Pasternack; Nikolaus B Binder; Gary W Moore Journal: Int J Mol Sci Date: 2021-01-20 Impact factor: 5.923