Circulating Inhibitor in an Elderly Female That Impairs the Action of Human But Not Rabbit Brain Thromboplastin
Abstract number: P1911
Messmore1,2 HL, Adess1,2 M, Fabbrini2 N, Choudhury1,2 A, Bhoopalam1,2 N, Diaz1 M, Iqbal1 A, Balbale2 S, Love2 B, Zarr2 C, Schlimm2 S, Bird2 ML
A 71 year old female with dementia (ischemic strokes in the past), no history of overt bleeding, a history of abnormal coagulation tests for over 10 years, iron deficiency anemia (on oral aspirin chronically), diabetes mellitus (adult onset), and no other significant problems was found to have a markedly prolonged prothrombin time (PT) with a normal activated partial thromboplastin time (APTT). Coagulation testing revealed the following results:
PT: 110 seconds, 80.3 seconds, 77.1 seconds (Ref Range 9.011.8 seconds)
APTT: 29.5 seconds, 29 seconds, 29 seconds (Ref Range 2234 seconds)
Thrombin Time: 17.9 seconds (Ref Range 1221 seconds)
Fibrinogen: 598 mg/dL (Ref Range 200400 mg/dL)
Inhibitor Screen: Positive (Immediate Acting)
Lupus Anticoagulant Screening Profile: Negative
Factor Assays V, VII, VIII, IX, X, II were all normal
ANA, anti-DS DNA, Immunoglobulin Assays and Blood Viscosity were normal
Additional studies revealed a prothrombin time with rabbit brain thromboplastin (Dade® Thromboplastin C Plus®) of 13.2 seconds as compared with a prothrombin time of 79.4 seconds with recombinant human tissue factor thromboplastin (Dade® Innovin®).
The patient's serum was inhibitory to Innovin® but not to Thromboplastin C Plus® as determined by mixing her serum 1 : 1 with normal human plasma. The inhibition was immediate. Recombinant Factor VIIa (NovoSeven®) added to her plasma partially corrected the abnormal prothrombin time when supplemented at therapeutic concentrations in vitro.
Conclusion: Inhibitor of human tissue factor by both patient serum and plasma.
To cite this abstract use the following format:
Journal of Thrombosis and Haemostasis 2005; Volume 3, Supplement 1: abstract number
|Session name:||XXIst ISTH Congress|
|Subject:||Poster Session Thursday|
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