open access

Vol 49, No 1 (2018)
Case Report
Published online: 2018-03-30
Submitted: 2017-02-01
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False-negative coagulation factor activity results due to the presence of antiphospholipid antibodies in a case of autoimmune hemolytic anemia

Takeshi Sugimoto, Kazuhide Morimoto, Hiromi Hashimoto, Yukie Kaneda, Shinya Ohata, Yoshiro Yasutomo
DOI: 10.2478/ahp-2018-0007
·
Acta Haematol Pol 2018;49(1):37-41.

open access

Vol 49, No 1 (2018)
Case Report
Published online: 2018-03-30
Submitted: 2017-02-01

Abstract

An 88-year-old female was admitted with autoimmune hemolytic anemia (AIHA). Coagulation test revealed severe prolongation of activated partial thromboplastin time (APTT). APTT cross-mixing test with patient plasma and normal plasma demonstrated an inhibitory pattern. Several intrinsic coagulation factor activities, particularly factor IX, showed remarkable decreases, and the inhibitor titers for coagulation factors VIII and IX were elevated. Although AIHA with existing antiphospholipid (aPL) antibodies was diagnosed initially, purpura developed on extremities intermittently during the clinical course. Considering the possibility of coexisting acquired hemophilia, APTT cross-mixing test with patient’s plasma and equal amount of the recombinant factor VIII product instead of normal plasma was performed. The APTT value on equal mixing samples with patient plasma and recombinant factor VIII product was decreased to within the normal range, and coagulation factor IX activity was restored. These results indicate that the recombinant factor VIII product had a neutralizing effect on aPL antibodies. We concluded that recombinant factor VIII product may lead to the repair of incorrect results from the APTT-dependent diagnostic system in the presence of aPL antibodies.

Abstract

An 88-year-old female was admitted with autoimmune hemolytic anemia (AIHA). Coagulation test revealed severe prolongation of activated partial thromboplastin time (APTT). APTT cross-mixing test with patient plasma and normal plasma demonstrated an inhibitory pattern. Several intrinsic coagulation factor activities, particularly factor IX, showed remarkable decreases, and the inhibitor titers for coagulation factors VIII and IX were elevated. Although AIHA with existing antiphospholipid (aPL) antibodies was diagnosed initially, purpura developed on extremities intermittently during the clinical course. Considering the possibility of coexisting acquired hemophilia, APTT cross-mixing test with patient’s plasma and equal amount of the recombinant factor VIII product instead of normal plasma was performed. The APTT value on equal mixing samples with patient plasma and recombinant factor VIII product was decreased to within the normal range, and coagulation factor IX activity was restored. These results indicate that the recombinant factor VIII product had a neutralizing effect on aPL antibodies. We concluded that recombinant factor VIII product may lead to the repair of incorrect results from the APTT-dependent diagnostic system in the presence of aPL antibodies.

Get Citation

Keywords

antiphospholipid antibody; anticoagulant inhibitor; APTT cross-mixing test; acquired hemophilia

About this article
Title

False-negative coagulation factor activity results due to the presence of antiphospholipid antibodies in a case of autoimmune hemolytic anemia

Journal

Acta Haematologica Polonica

Issue

Vol 49, No 1 (2018)

Pages

37-41

Published online

2018-03-30

DOI

10.2478/ahp-2018-0007

Bibliographic record

Acta Haematol Pol 2018;49(1):37-41.

Keywords

antiphospholipid antibody
anticoagulant inhibitor
APTT cross-mixing test
acquired hemophilia

Authors

Takeshi Sugimoto
Kazuhide Morimoto
Hiromi Hashimoto
Yukie Kaneda
Shinya Ohata
Yoshiro Yasutomo

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