Using weighted harmonic mean for prediction of APTT in the mixing test

Background: The mixing test of activated partial thromboplastin time (APTT) is used for differentiating factor deficiency (FD), lupus anticoagulant (LAC), and acquired hemophilia A (AHA). However, the interpretation of the mixing test is not fully standardized. Objectives: The aim of this study was...

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Main Authors: Mitsuhiro Uchiba, Masao Matsuoka
Format: Article
Language:English
Published: Elsevier 2022-08-01
Series:Thrombosis Update
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2666572722000189
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author Mitsuhiro Uchiba
Masao Matsuoka
author_facet Mitsuhiro Uchiba
Masao Matsuoka
author_sort Mitsuhiro Uchiba
collection DOAJ
description Background: The mixing test of activated partial thromboplastin time (APTT) is used for differentiating factor deficiency (FD), lupus anticoagulant (LAC), and acquired hemophilia A (AHA). However, the interpretation of the mixing test is not fully standardized. Objectives: The aim of this study was to determine whether the weighted harmonic mean predicts the APTT in mixture of a mixing test samples and is useful for the differentiation of FD, LAC, and AHA. Patients/methods: We examined 27 FD, 26 LAC, and 18 AHA samples. Harmonic means of APTT were calculated from the clotting times with and without 2 h incubation. We defined the index of harmonic mean (IHM) as the ratio of the actual APTT to the predicted APTT calculated by the harmonic mean. We defined IHM of the measured immediate after mixing samples and of delayed (after 2 h of incubation) measured samples as IHMi and IHMd respectively. Results: Actual APTT and predicted APTT were correlated in the FD group. Both IHMi and IHMd in the FD group were equal or lower than 1.02, whereas those in the LAC group were higher than 1.02. In the AHA group, the IHMd was higher than 1.02, whereas half of the IHMi were equal or lower than 1.02. Time dependent inhibition evaluated by IHMd/IHMi was not observed in the LAC group, whereas it was observed in 77% of participants in the AHA group. Conclusions: The harmonic mean was potentially useful in predicting APTT in the mixing test, and the IHM calculated from the predicted APTT had differentiation potency for FD and LAC, and for FD and AHA. IHM was also available for partial differentiation of LAC to AHA.
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spelling doaj.art-aa8693cd15f54ee2aeed97401e6c78f12022-12-22T01:42:48ZengElsevierThrombosis Update2666-57272022-08-018100114Using weighted harmonic mean for prediction of APTT in the mixing testMitsuhiro Uchiba0Masao Matsuoka1Corresponding author.; Department of Blood Transfusion and Cell Therapy, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto, 860-8811, JapanDepartment of Blood Transfusion and Cell Therapy, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto, 860-8811, JapanBackground: The mixing test of activated partial thromboplastin time (APTT) is used for differentiating factor deficiency (FD), lupus anticoagulant (LAC), and acquired hemophilia A (AHA). However, the interpretation of the mixing test is not fully standardized. Objectives: The aim of this study was to determine whether the weighted harmonic mean predicts the APTT in mixture of a mixing test samples and is useful for the differentiation of FD, LAC, and AHA. Patients/methods: We examined 27 FD, 26 LAC, and 18 AHA samples. Harmonic means of APTT were calculated from the clotting times with and without 2 h incubation. We defined the index of harmonic mean (IHM) as the ratio of the actual APTT to the predicted APTT calculated by the harmonic mean. We defined IHM of the measured immediate after mixing samples and of delayed (after 2 h of incubation) measured samples as IHMi and IHMd respectively. Results: Actual APTT and predicted APTT were correlated in the FD group. Both IHMi and IHMd in the FD group were equal or lower than 1.02, whereas those in the LAC group were higher than 1.02. In the AHA group, the IHMd was higher than 1.02, whereas half of the IHMi were equal or lower than 1.02. Time dependent inhibition evaluated by IHMd/IHMi was not observed in the LAC group, whereas it was observed in 77% of participants in the AHA group. Conclusions: The harmonic mean was potentially useful in predicting APTT in the mixing test, and the IHM calculated from the predicted APTT had differentiation potency for FD and LAC, and for FD and AHA. IHM was also available for partial differentiation of LAC to AHA.http://www.sciencedirect.com/science/article/pii/S2666572722000189Coagulation factor deficiencyAcquired hemophiliaLupus anticoagulantAPTTMixing test
spellingShingle Mitsuhiro Uchiba
Masao Matsuoka
Using weighted harmonic mean for prediction of APTT in the mixing test
Thrombosis Update
Coagulation factor deficiency
Acquired hemophilia
Lupus anticoagulant
APTT
Mixing test
title Using weighted harmonic mean for prediction of APTT in the mixing test
title_full Using weighted harmonic mean for prediction of APTT in the mixing test
title_fullStr Using weighted harmonic mean for prediction of APTT in the mixing test
title_full_unstemmed Using weighted harmonic mean for prediction of APTT in the mixing test
title_short Using weighted harmonic mean for prediction of APTT in the mixing test
title_sort using weighted harmonic mean for prediction of aptt in the mixing test
topic Coagulation factor deficiency
Acquired hemophilia
Lupus anticoagulant
APTT
Mixing test
url http://www.sciencedirect.com/science/article/pii/S2666572722000189
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