Hemostasis in Patients With Idiopathic Thrombocytopenic Purpura

Study Overview
=================
Brief Summary
-----------------
The investigators are trying to investigate the coagulation status of idiopathic (immune) thrombocytopenic purpura patients by measuring the platelet count, coagulation battery, von Willebrand factor level, thromboelastography.

Detailed Description
-----------------
In patients with chronic coagulation disorder, laboratory model and clinical data have shown evidence for a rebalanced hemostasis. Previous study showed that the platelet count may not predict the risk of bleeding since the platelet count is not an indicator of platelet function. Thromboelastography may be the choice of investigation when platelet function is in question especially in patients with idiopathic (immune) thrombocytopenic purpura (ITP). Previous study have shown that maximum clot formation is the most important thromboelastography parameter in predicting bleeding in ITP patients that makes thromboelastography superior to other hemostatic tests. The investigators are trying to evaluate the rebalanced hemostasis in patients with ITP by comparing the value of platelet count, von Willebrand factor antigen level, and thromboelastography parameters.

Official Title
-----------------
Hemostasis in Patients With Idiopathic Thrombocytopenic Purpura

Conditions
-----------------
Idiopathic Thrombocytopenic Purpura

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Those who visits the outpatients clinic of Samsung Medical Center with a diagnosis of idiopathic (immune) thrombocytopenic purpura (ITP)between March, 2012 and February, 2013. Those with age between 20 and 70 yrs old Exclusion Criteria: Those with other causes of thrombocytopenia other than ITP

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| chronic ITP group<br>ITP patients with elevated level of vWF, ITP patients with preserved MA of thromboelastography | |
| acute ITP group<br>ITP patients with normal level of vWF, ITP patients with decreased MA of thromboelastography | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| maximum clot formation | thromboelastography parameters performed within 3 hours of blood sampling | within 3 hour of blood sampling | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| platelet count | platelet count | within 1 hours of blood sampling | 
| Coagulation battery results | prothrombin time (%, second, INR) activated partial thromboplastin time (sec) fibrinogen level (mg/dL) | within 1 hour after blood sampling | 
| von Willebrand factor antigen | von Willebrand factor antigen level | within 3 hours of blood sample | 
| clotting time | clotting time of Thromboelastography | within 3 hours of blood sampling | 
| alpha angle | alpha angle of thromboelastography parameter | within 3 hours of blood sample | 
| A10, A15, A20, A25 | amplitude 10, 15, 20, 25 minutes (mm) of thromboelastography parameter | within 3 hours of blood sampling | 
| LY 60 | maximum amplitude at 60 minutes of thromboelastography parameter | within 3 hours of blood sampling | 
| CLI | clot lysis index of thromboelastography parameter | within 3 hours of blood sampling | 
| Maximum lysis | Maximum lysis of thromboelastography parameter | within 3 hours of blood sampling | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
rebalanced hemostasis, idiopathic thrombocytopenic purpura, coagulation status