22 Questions
What is the product of the liver that has 5 glycosylated loops (kringles) bound to a lysine residue?
Plasminogen
What is the primary inhibitor of free plasmin?
Alpha-1 Antiplasmin
What is the last phase of normal clotting process when the patient tries to have wound or tissue injury?
Clot dissolution
What is the normal value of euglobulin clot lysis?
Lysis more than 2 hrs.
What is the role of factor 13 in the clotting process?
Stabilizing the fibrin clot
What is the result of excessive digestion of fibrin by plasmin?
Bleeding manifestation
What is the function of TAFI?
To hydrolyze lysine residues
What is the effect of the absence of activators in plasminogen?
Thrombus formation
What is the principle of D-Dimer test?
Immuno Assay
What is the role of plasmin in the clotting process?
Digesting the fibrin clot
What is the result of Plasminogen chromogenic substrate Assay?
Intensity of yellow color is directly proportional to plasminogen coagulation
What is the result of too much activation of plasminogen?
Bleeding manifestation
What is the activator used in Plasminogen chromogenic substrate Assay?
Streptokinase
What is the role of TPA (tissue plasminogen activators) in the clotting process?
Activating plasminogen
What is the half-life of TPA?
3 minutes
What is the primary function of PAI-1?
To inhibit plasminogen activators
What is the normal value of TPA in the blood?
5 mg/dl
What is the result of excessive plasminogen activation in cancer cells?
Primary fibrinolysis
What is the main difference between primary and secondary fibrinolysis?
Primary fibrinolysis is characterized by excessive plasminogen activation, while secondary fibrinolysis is characterized by inappropriate fibrin formation
What is the function of thrombin-thrombomodulin in fibrinolysis?
It activates TAFI
What is the result of a deficiency in PAI-1?
Increased plasminogen activation
What is the normal whole blood clotting time?
More than 48 hours
Study Notes
Tissue Plasminogen Activators (TPA)
- Has 2 glycosylated loops
- Half-life: 3 minutes
- Normal value: 5 mg/dL
- Produced by endothelial cells
- Binds to plasminogen activator inhibitor (PAI-1)
Urokinase Plasminogen Activator (UPA)
- Produced by urinary epithelial cells, monocytes, and macrophages
- Half-life: 7-15 minutes
- Normal value: 2-4 mg/mL
- Major activator produced by kidney
Fibrinolysis Inhibitors
- Alpha-2 antiplasmin: primary inhibitor of free plasmin
- Competes with plasminogen for lysine residue binding site
- Binds and inactivates plasmin
- Alpha-2 macroglobulin
- Thrombospondin
- Plasminogen activator inhibitor 1 (PAI-1)
- Principal inhibitor
- Allows binding of plasminogen
- Main activity: inhibits plasminogen activators (TPA and UPA)
- Produced by endothelial cells, megakaryocytes, smooth muscle cells, fibroblasts, monocytes, adipocytes, and hepatocytes
- PAI-2
Fibrinogen and Fibrin
- Fibrinogen: has 2 D-domains and 1 E-domain
- Fibrin: represents the original structure of fibrinogen
- Fibrin monomer: resulted from the action of thrombin on fibrinogen
- D-Dimer: fragments of fibrin that are produced during fibrinolysis
Tests for Fibrinolysis
- Whole blood clotting time
- Normal value: lysis more than 48 hours
- Abnormal: lysis less than 48 hours
- Euglobulin clot lysis
- Euglobulin: portion of plasma with fibrinogen, plasminogen, and plasmin activators
- Procedure: plasma + HAc (pptn) → dissolve in buffer + thrombin (to digest)
- Normal value: lysis more than 2 hours
- Abnormal: lysis less than 2 hours
- Protamine sulfate test for fibrin monomer
- Ethanol gelation test for fibrin monomer
- D-Dimer test
- Specific for DIC
- Positive for D-dimer means positive in DIC
- Principle: immunoassay (test for D-dimer)
- Plasminogen chromogenic substrate assay
- Principle: measures plasminogen activity
- Result: intensity of yellow color directly proportional to plasminogen concentration
- Normal value: 5-13.5 mg/dL
This quiz covers the processes of fibrinolysis and clotting in hematology, including the roles of plasmine, fibrinogen, and lysine residues.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
