Related Experiment Video

Updated: Jul 3, 2026

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
13:08

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay

Published on: September 9, 2012

[High-titer idiopathic acquired factor V inhibitor patient showing decreased activities of multiple coagulation

Ikuo Shimizu1, Naoaki Ichikawa, Mihoko Yotsumoto

  • 1Department of Hematology, Nagano Red Cross Hospital.

[Rinsho Ketsueki] the Japanese Journal of Clinical Hematology
|July 24, 2008
PubMed

Insights

A high-titer acquired factor V inhibitor caused oral bleeding and coagulation abnormalities in a 72-year-old male. Prednisolone treatment resolved symptoms, highlighting the inhibitor's impact on coagulation tests.

Area of Science:

  • Hematology
  • Immunology

Background:

  • Acquired factor inhibitors are rare autoimmune disorders.
  • Factor V inhibitors can cause severe bleeding complications.

Observation:

  • A 72-year-old male presented with oral bleeding and significantly prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT).
  • Laboratory tests revealed severely reduced Factor V (FV) activity (<3%) and a high-titer FV inhibitor (240 BU/ml).
  • Decreased activity of Factors II and X was also noted, with a mixing test showing no correction of PT.

Findings:

  • The patient had an acquired factor V inhibitor leading to bleeding and laboratory abnormalities.
  • Treatment with prednisolone effectively resolved the oral bleeding and corrected the coagulation parameters.
  • The high-titer FV inhibitor significantly impacted coagulation assay results.

Implications:

  • This case underscores the diagnostic challenges posed by high-titer acquired factor inhibitors.
  • Effective management with immunosuppressive therapy can lead to favorable outcomes.
  • Understanding inhibitor behavior is crucial for accurate laboratory interpretation and patient care.

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