Fletcher Factor Deficiency, Source of Variations of the Activated Partial Thromboplastin Time Test

1981 ◽  
Vol 75 (4) ◽  
pp. 626-628 ◽  
Author(s):  
Kenneth Entes ◽  
Frank M. Laduca ◽  
Kamal D. Tourbaf
Keyword(s):  
Partial Thromboplastin Time ◽  
Activated Partial Thromboplastin Time ◽  
Factor Deficiency ◽  
Time Test ◽  
Fletcher Factor

Long-term safety outcomes of prekallikrein (Fletcher factor) deficiency: A systematic literature review of case reports

2020 ◽  
Vol 41 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Antonio Girolami ◽  
Catherine Rolland ◽  
Dan Sexton ◽  
Moshe Vardi ◽  
Jonathan A. Bernstein
Keyword(s):  
Lupus Erythematosus ◽  
Partial Thromboplastin Time ◽  
Case Reports ◽  
Activated Partial Thromboplastin Time ◽  
Plasma Kallikrein ◽  
Time Data ◽  
Factor Deficiency ◽  
Fletcher Factor ◽  
The Impact

Background: Hereditary prekallikrein (Fletcher factor) deficiency is a rare condition characterized by a prolonged activated partial thromboplastin time. Inhibitors of plasma kallikrein have recently been approved for prophylaxis of hereditary angioedema and are under investigation for use in other indications. Objective: We attempted to conservatively assess the impact of long-term inhibition of this pathway by reviewing reported comorbidities in patients with hereditary prekallikrein deficiency. Methods: We searched several medical literature databases for publications that reported data from patients with hereditary prekallikrein deficiency (<10% of normal and/or shortening of activated partial thromboplastin time on increased incubation time). Data reporting of cardiovascular, bleeding, and autoimmune-related diseases were extracted. Results: Of 1966 publications screened, 45 publications (which represented 53 patients with prekallikrein deficiency) were included. Among 53 identified patients with prekallikrein deficiency, 25 were explicitly defined as asymptomatic, with no comorbidities mentioned in another three cases. Another 16 of the 53 patients were described as having undergone surgery or dental extractions with no complications. Cardiovascular comorbidities were reported in 19 patients, mainly hypertension (9 patients) and cerebrovascular ischemia or stroke (5 patients). Excessive bleeding episodes after surgery were reported in four patients. Autoimmune-related diseases were reported for three patients (two with Graves disease and one with systemic lupus erythematosus). Conclusion: This review identified patients with hereditary prekallikrein deficiency who reported a spectrum of health outcomes from asymptomatic to infrequent reports of cardiovascular, bleeding, and autoimmune comorbidities. The majority of the reports did not indicate any association between prekallikrein deficiency and comorbidities; however, additional observation is required to confirm the long-term safety of plasma kallikrein inhibition.

Long-term safety outcomes of prekillikrein (Fletcher factor) deficiency: A systematic literature review of case reports

2019 ◽  
Author(s):  
Antonio Girolami ◽  
Catherine Rolland ◽  
Dan Sexton ◽  
Moshe Vardi ◽  
Jonathan A. Bernstein
Keyword(s):  
Lupus Erythematosus ◽  
Partial Thromboplastin Time ◽  
Case Reports ◽  
Activated Partial Thromboplastin Time ◽  
Plasma Kallikrein ◽  
Excessive Bleeding ◽  
Factor Deficiency ◽  
Fletcher Factor ◽  
The Impact

Background: Hereditary prekallikrein (Fletcher factor) deficiency is a rare condition characterized by a prolonged activated partial thromboplastin time. Inhibitors of plasma kallikrein have recently been approved for prophylaxis of hereditary angioedema and are under investigation for use in other indications.Objective: We attempted to conservatively assess the impact of long-term inhibition of this pathway by reviewing reportedcomorbidities in patients with hereditary prekallikrein deficiency.Methods: We searched several medical literature databases for publications that reported data from patients with hereditaryprekallikrein deficiency (<10% of normal and/or shortening of activated partial thromboplastin time on increased incubationtime). Data reporting of cardiovascular, bleeding, and autoimmune-related diseases were extracted.Results: Of 1966 publications screened, 45 publications (which represented 53 patients with prekallikrein deficiency) wereincluded. Among 53 identified patients with prekallikrein deficiency, 25 were explicitly defined as asymptomatic, with no comorbidities mentioned in another three cases. Another 16 of the 53 patients were described as having undergone surgery or dental extractions with no complications. Cardiovascular comorbidities were reported in 19 patients, mainly hypertension (9 patients) and cerebrovascular ischemia or stroke (5 patients). Excessive bleeding episodes after surgery were reported in four patients. Autoimmune-related diseases were reported for three patients (two with Graves disease and onewith systemic lupus erythematosus).Conclusion: This review identified patients with hereditary prekallikrein deficiency who reported a spectrum of health outcomes from asymptomatic to infrequent reports of cardiovascular, bleeding, and autoimmune comorbidities. The majority of the reports did not indicate any association between prekallikrein deficiency and comorbidities; however, additional observation is required to confirm the long-term safety of plasma kallikrein inhibition.

Time test

1998 ◽  
Vol 79 (3) ◽  
pp. 227-231
Author(s):  
L. N. Tarasova ◽  
E. Yu. Savinykh ◽  
G. K. Platonov ◽  
L. L.N. Tonin ◽  
O. I. Rechkin
Keyword(s):  
Partial Thromboplastin Time ◽  
Raw Materials ◽  
Test Tube ◽  
Activated Partial Thromboplastin Time ◽  
Therapy Control ◽  
The World ◽  
Time Test

The data on standardization of the activated partial thromboplastin time test all over the world and in Russia are given. The method is used as a screening one and it is of importance for revealing disorders in the first coagulation phase (hemophilia diagnosis) and heparinotherapy control. Two lyophilized forms of partial thromboplastin made of cadaverine raw materials are developed. Their specificity in revealing hemophilia, therapy control by heparin fit for a year is confirmed. The diagnosticum of one of them is a basis of the kit for determining the activated partial thromboplastin time. The possibility of its use not only in performing the test by test tube methods but as well by semiautomatic and automatic machines.

scholarly journals A Multicenter Evaluation of an Activated Partial Thromboplastin Time Test, Cepho-Test

1977 ◽  
Author(s):  
D. Collen ◽  
H.C. Godal ◽  
P.M. Mannucci ◽  
I.M. Nilsson ◽  
C. Gilhuus-Moe ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Partial Thromboplastin Time ◽  
High Sensitivity ◽  
Mean Value ◽  
Activated Partial Thromboplastin Time ◽  
Satisfactory Precision ◽  
Time Test ◽  
The Mean ◽  
Aptt Reagent ◽  
Control Plasma

To compare the sensitivity and precision of the Activated Partial Thromboplastin Time (APTT) test Cephotest to that of APTT methods in current use, Cepho-test and current APTT method (Leuven and Milan: Locally modified Thrombofax/kaolin procedures; Malmoe: Automated APTT; Oslo: APTT of human brain/kaolin) were performed in parallel (20 tests) on lyophilized standard plasmas of 4 levels of factors VIII. The mean value (1 standard deviation) of Cephotest on Control Plasma Normal was 36.3 (2.21) s in Leuven, 31.7 (1.13) s in Oslo, 35.0 (1.36) s in Milan and 35.0 (1.16) s in Malmoe. The corresponding values of the local APTT methods were 50.2 (I.58) s, 34.5 (1.27) s, 51.9 (1.17) s and 38.8 (1.23) s, respectively. In Oslo, Milan and Malmoe, the sensitivity of Cephotest was superior to that of the local APTT reagent at all levels of factor VIII. In Leuven, the local APTT method had a higher ratio than Cephotest. There was no statistical significant differences between the standard deviation of Cephotest and the local APTT methods. The study indicates that Cephotest has a high sensitivity, satisfactory precision and is subjected to only minor interlaboratory variations.

One-step chromogenic equivalent of activated partial thromboplastin time evaluated for clinical application

1991 ◽  
Vol 37 (7) ◽  
pp. 1235-1244 ◽  
Author(s):  
Gabriëlle E Ponjee ◽  
Huib L Vader ◽  
Net J de Wild ◽  
Ger W T Janssen ◽  
Fedde van der Graaf
Keyword(s):  
Partial Thromboplastin Time ◽  
Clinical Laboratory ◽  
Intrinsic Factor ◽  
Activated Partial Thromboplastin Time ◽  
Factor Vii ◽  
Factor Deficiency ◽  
One Step ◽  
The One

Abstract We evaluated the clinical usefulness of a recently developed semi-automated one-step chromogenic equivalent of activated partial thromboplastin time (APTT; Behring). This simple test is easily adaptable for automation. Generally, the results with this chromogenic one-step APTT were at least as precise as those obtained with comparative coagulometric methods. The chromogenic one-step APTT showed, both in vitro and in vivo, adequate sensitivity to congenital intrinsic factor deficiency but no sensitivity to Factor VII deficiency. Unlike a two-step coagulometric APTT (Dade), the one-step chromogenic APTT seemed sensitive to activation products of the contact system, which are present in immunoadsorbed factor-deficient plasma. The in vitro sensitivity of the chromogenic APTT to heparin was comparable with that of a coagulometric APTT, but the sensitivity to heparin in patients' samples differed slightly. The chromogenic APTT is relatively insensitive to anomalies in the fibrinogen-fibrin conversion. Finally, we observed discrepancies between the chromogenic and coagulometric APTT results for plasma of patients with disseminated intravascular coagulation. We conclude that this one-step chromogenic APTT warrants further evaluation for possible use as a routine test for the clinical laboratory.

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