Eligibility Criteria:
Normal Controls:
Inclusion Criteria
* Males and females age 21 years or older.
* Able and willing to provide written informed consent. Exclusion Criteria
* Abnormal results from assays used to establish clinical truth (retrospective exclusion).
* Hospitalization or doctor's visits within prior 30 days, except for routine checkup/physical examination.
* Use of antiplatelet therapy within the past 14 days, e.g. aspirin, clopidogrel, prasugrel, ticagrelor, cilostazol.
* Use of anticoagulant drugs within the past 14 days, e.g. heparin, bivalirudin, warfarin, rivaroxaban, and apixaban.
* Use of certain nonsteroidal anti-inflammatory drugs (NSAIDs) such as celecoxib, rofecoxib, etc. within the past 14 days.
* History of anemia.
* Known thrombocytopenia (platelet count \< 100,000/μL).
* Significant renal dysfunction or dialysis.
* History of platelet disorders e.g. von Willebrand factor deficiency, Glanzmann's thrombasthenia or Bernard-Soulier syndrome.
* History of hemophilia or bleeding disorders.
* History of bleeding, with Bleeding Score ≥ 5 (Tosetto J Thromb Haemost 2006). See Appendix A. Scores will be assigned based on health history according to the following categories:
* Epistaxis
* Cutaneous bleeding
* Bleeding from minor wounds
* Bleeding from oral cavity
* Gastrointestinal bleeding
* Bleeding from tooth extraction
* Surgical bleeding
* Menorrhagia
* Post-partum hemorrhage
* Muscle hematoma
* Hemarthrosis
* Central nervous system bleeding
* Females who are in the last trimester of pregnancy, or are breastfeeding.
* Known active gastrointestinal disease including peptic ulcers, gastro-esophageal reflux disease (GERD), and hyperacidity.
* Currently participating in a study involving an investigational drug or compound known to affect coagulation or hemostasis.
* Subjects with significant past medical history as determined by the Investigator that would pose safety concerns or interfere with the study goals.
Antiplatelet Therapy Subjects:
Inclusion Criteria
* Males and females age 21 years or older.
* Continuous daily ingestion of one of the following antiplatelet therapy regimens:
* 81 mg or higher aspirin
* 81 mg or higher aspirin plus 75 mg daily clopidogrel
* 81 mg or higher aspirin plus 10 mg daily prasugrel
* 81 mg aspirin plus 180 mg daily ticagrelor
* Able and willing to provide written informed consent. Exclusion Criteria
* Use of antiplatelet therapy besides aspirin (e.g. clopidogrel, prasugrel, ticagrelor, cilostazol, abciximab, eptifibatide) within the past 14 days.
* Use of anticoagulant drugs within the past 14 days, e.g. heparin, bivalirudin, warfarin, rivaroxaban, and apixaban.
* Use of certain nonsteroidal anti-inflammatory drugs (NSAIDs) such as celecoxib, rofecoxib, etc. within the past 14 days.
* Significant renal dysfunction or dialysis.
* Known thrombocytopenia (platelet count \< 100,000/μL).
* History of platelet disorders e.g. von Willebrand factor deficiency, Glanzmann thrombasthenia or Bernard-Soulier syndrome.
* History of hemophilia or bleeding disorders.
* Females who are in the last trimester of pregnancy, or are breastfeeding.
* Known active gastrointestinal disease including peptic ulcers, gastro-esophageal reflux disease (GERD), and hyperacidity.
* Currently participating in a study involving an investigational drug or compound known to affect coagulation or hemostasis.
* Subjects with significant past medical history as determined by the Investigator that would pose safety concerns or interfere with the study goals.
vWD Subjects: Inclusion Criteria
* Males and females age 21 years or older.
* Prior diagnosis of von Willebrand disease type 1, 2A, 2B, 2M, or 3
* History of bleeding, with Bleeding Score ≥ 5, which is 99% specific for vWD (Tosetto J Thromb Haemost 2006). See Appendix A. Scores will be assigned based on health history according to the following categories:
* Epistaxis
* Cutaneous bleeding
* Bleeding from minor wounds
* Bleeding from oral cavity
* Gastrointestinal bleeding
* Bleeding from tooth extraction
* Surgical bleeding
* Menorrhagia
* Post-partum hemorrhage
* Muscle hematoma
* Hemarthrosis
* Central nervous system bleeding
* Able and willing to provide written informed consent. Exclusion Criteria
* Prior diagnosis of von Willebrand disease type 2N
* Receiving desmopressin or vWF replacement therapy within the past 2 weeks.
* Use of antiplatelet therapy within the past 14 days.
* Use of anticoagulant drugs within the past 14 days, e.g. heparin, bivalirudin, warfarin, rivaroxaban, and apixaban.
* Use of certain nonsteroidal anti-inflammatory drugs (NSAIDs) such as celecoxib, rofecoxib, etc. within the past 14 days.
* Significant renal dysfunction or dialysis.
* Known thrombocytopenia (platelet count \< 100,000/μL).
* Females who are in the last trimester of pregnancy, or are breastfeeding.
* Currently participating in a study involving an investigational drug or compound known to affect coagulation or hemostasis.
* Subjects with significant past medical history as determined by the Investigator that would pose safety concerns or interfere with the study goals.
Glanzmann's Thrombasthenia Subjects:
Inclusion Criteria
* Males and females age 21 years or older.
* Prior diagnosis of Glanzmann's thrombasthenia
* History of bleeding.
* Able and willing to provide written informed consent. Exclusion Criteria
* Use of antiplatelet therapy within the past 14 days.
* Use of anticoagulant drugs within the past 14 days, e.g. heparin, bivalirudin, warfarin, rivaroxaban, and apixaban.
* Use of certain nonsteroidal anti-inflammatory drugs (NSAIDs) such as celecoxib, rofecoxib, etc. within the past 14 days.
* Significant renal dysfunction or dialysis.
* Known thrombocytopenia (platelet count \< 100,000/μL).
* Females who are in the last trimester of pregnancy, or are breastfeeding.
* Currently participating in a study involving an investigational drug or compound known to affect coagulation or hemostasis.
* Subjects with significant past medical history as determined by the Investigator that would pose safety concerns or interfere with the study goals.