Coagulation:- part 1 – Blood Coagulation process, Coagulation factors Assay, and factors deficiency

Sample

1. The plasma is needed, take 5 ml of venous blood and add sodium citrate as the anticoagulant.
2. Perform the assay immediately or as soon as possible.
3. For factors II, V, VII, and X,  place the citrated plasma on ice immediately, and the sample is stable for 2 hours.
   1. Freeze if it is delayed >2 hours.

Purpose of the test (Indications)

1. To measure the coagulation factor concentration in the blood.
2. To find the inherited or acquired bleeding disorders.
3. If there is a history of bruises or excessive bleeding.
4. If there are prolonged PT or PTT.
5. Acquired conditions like Vit. K deficiency or liver disease.
6. Maybe advised to monitor the treatment of a patient with factor deficiency.

Pathophysiology

1. Definition of blood coagulation:
   1. Blood coagulation is the process that consists of a series of biochemical reactions that will transform the blood coagulation factors into an insoluble gel through the conversion of soluble fibrinogen into fibrin.
2. Blood coagulation factors can be divided by physical properties:
   1. Contact proteins:
      1. Hageman factor (XII).
      2. Plasma thromboplastin component (XI).
      3. Prekallikeri (PK).
      4. High molecular weight kininogen (HMWK).
   2. Prothrombin protein:
      1. Prothrombin (II).
      2. Stable factor (VII).
      3. Christmas factor (IX).
      4. Stuart-Power factor (X).
   3. Fibrinogen group:
      1. Fibrinogen (I).
      2. Labile factor (V).
      3. Antihemophilic factor (VIII).
      4. Fibrin stabilizing factor (XIII).

3. Deficiency of these blood coagulation factors may be due to:
   1. Inherited genetic defects.
   2. Acquired.
   3. Drugs therapy.
4. Causes of acquired factor deficiency are:
   1. Snake venom.
   2. Liver diseases.
   3. Uremia.
   4. Vit. K deficiency.
   5. Anticoagulant ingestion of warfarin.
   6. Massive blood transfusion.
   7. Some of the cancers.
   8. Disseminated intravascular coagulopathy.
5. There is a balance between the factors leading to clotting and the factors causing dissolution.
6. The first reaction of the body to bleeding is constriction of the blood vessels.
   1. This will be effective in small blood vessel injuries but not in large blood vessels.

Process of blood coagulation:

1. In large blood vessel injuries, the clotting factors activate to plug the injured site.
2. The primary phase is initiated by platelets aggregation.
3. The secondary phase is the activation of clotting factors.
4. In phase three, factor X is activated by proteases (VIIa, IXa with XIIIa).
   1. V1Ia can activate 1X and X directly.
      

      blood clotting mechanism stages

 The blood clotting pathways are:

The intrinsic pathway where the factor XII and other proteins form a complex on the injured endothelium.

1. XII   XIIa    XI to  XIa complex form of VIII + XI + X
2. Activated X is formed.
3. Then the common pathway starts.
   

   Intrinsic pathway

   

   Intrinsic pathway cycle

The extrinsic pathway is a complex formation between the Tissue factor (factor III or thromboplastin) and factor VII.

1. Activated factor VIIa forms which stimulate factor X.
2. Alternately factor VIIa activates factor IX and X.
   

   Extrinsic pathway

   

   Extrinsic pathway cycle

Common pathway Xa     Prothrombin to Thrombin in the presence of factor V, calcium, and phospholipids on the surface of platelets.

1. Thrombin     Fibrinogen Fibrin is polymerized into the stable clot.
2. Thrombin also activates factor VIII to stimulate platelet aggregation and fibrin polymerization.
3. Prothrombin is a Vit K-dependent factor.
   

   Common pathway

   

   Common pathway

   

   Summary of the coagulation pathway

4. Plasmin degenerates the fibrin polymer into fragments that are taken up by the phagocytic cells.
5. Fibrinogen is considered an acute phase protein and is increased in many diseases.
6. Factor XII deficiency was observed as an increased risk of Myocardial infarction and venous thrombosis.
   1. Fibrinogen is also considered a coronary risk factor and stroke.
7. Determine the exact factor deficiency for the replacement therapy.

Normal values of clotting factors

Factors	Normal value Source 1	Normal value Source 2	Normal value Source 3
Fibrinogen	Adult = 200 to 400 mg/dL Newborn = 125 to 300 mg/dL		200 to 400 mg/dL
	Quantitation minimum hemostatic level  mg/dL		Plasma concentration  mg/dL
Factor II (Prothrombin)	10 to 15 mg/dL	80 to 120 % of normal	10 to 15
Factor III (Thromboplastin)
Factor IV (Ionized calcium)	4.60 to 5.08 mg/dL
Factor V (Labile Factor)	5 to 10 mg/dL	50 to 150% of normal	0.5 to 1.0
Factor VI	Not existing
Factor VII (Stable factor)	5 to 20 mg/dL	65 to 140% of normal	0.2
Factor VIII (Antihemophilic factor)	30 mg/dL	55 to 145% of normal	1.0 to 2.0
Factor IX (Christmas factor)	30 mg/dL	60 to 140% of normal	0.3 to 0.4
Factor X (Stuart factor)	8 to 10 mg/dL	45 to 155% of normal	0.6 to 0.8
Factor XI (Plasma thromboplastin)	25 mg/dL	65 to 135% of normal	0.4
Factor XII (Hageman factor)		50 to 150% of normal	2.9
Factor XIII (Fibrin-stabilizing factor)			2.5
Von Willebrand factor			1.0

• Reference values are different from various sources.

Fibrinogen

1. Fibrinogen level increased is seen in:

   1. Acute inflammatory reactions.
   2. Trauma.
   3. Coronary heart disease.
   4. Cigarette smoking.

2. Fibrinogen decreased level is seen in:

   1. Liver diseases like hepatitis and cirrhosis.
   2. DIC ( disseminated intravascular coagulopathy ).
   3. Fibrinolysis.

Prothrombin

1. The decreased level is seen in:
   1. Vit. K deficiency.
   2. Liver disease.
   3. Oral anticoagulants.
   4. Circulating inhibitor or lupus-like anticoagulants.
   5. Decreased synthesis.

Factor V deficiency:

1. Liver diseases.
2. Factor V inhibitor.
3. Myeloproliferative disorders.
4. DIC and fibrinolysis.
5. Mild decrease in the newborn.

Factor VII deficiency:

1. Liver diseases.
2. Kwashiorkor.
3. Normal newborn.
4. Treatment with coumarin-like drugs.

Factor VIII

1. Factor VIII increased in:
   1. Late normal pregnancy.
   2. Thromboembolic conditions.
   3. Liver diseases.
   4. Postoperative patients.
   5. Normal newborn.
   6. Rebound phenomenon after sudden stoppage of coumarin-like drugs.
2. Factor VIII deficiency:
   1. due to the presence of factor VIII inhibitors.
   2. DIC.
   3. Von Willebrand disease.
   4. Myeloproliferative disorders.

Factor IX deficiency:

1. Liver diseases and cirrhosis.
2. Nephrotic syndrome.
3. Anticoagulant antibody formation.
4. Normal newborn.
5. Drugs like Dicoumarol.
6. DIC.
7. Vit K Deficiency.

Factor X deficiency:

1. Vit K deficiency.
2. Liver Diseases.
3. Oral anticoagulants.
4. DIC.
5. Amyloidosis.
6. Normal newborn.

Factor XI deficiency:

1. Liver diseases.
2. Intestinal malabsorption leads to Vit K deficiency.
3. DIC.
4. Newborn.

Factor XII deficiency:

1. Nephrotic syndrome.
2. Liver diseases.
3. Chronic myelocytic leukemia.
4. Normal newborn.

Factor XIII deficiency:

1. Postoperative patients.
2. Liver diseases.
3. In persistent increased fibrinogen level.
4. Acute myeloid leukemia.
5. DIC.
6. Circulating anticoagulants.

Diseases leading to coagulation factor deficiency:

Disease	Factor deficiency
Disseminated intravascular coagulopathy	I, V, VIII                                                 (1, 5, 8)
Liver diseases	I, II, V, VII, IX, X, XI                             (1, 2, 5,7, 9. 10, 11)
Autoimmune diseases	VIII                                                        (8)
Congenital deficiency	I, II, V, VII, VIII, IX, X, XI, XII             (1, 2, 5, 7, 8, 9, 10, 11, 12)
Vit K deficiency	II, VII, IX, X, XI                                     (2, 7, 9, 11)
Heparin therapy	II                                                             (2)
Warfarin therapy	II, VII, IX, X, XI                                     (2, 7, 9, 10, 11)
Fibrinolysis	I, V, VIII                                                  (1, 5, 8)

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