Approach to a Case of Coagulation Disorder

APPROACH TO A CASE OF COAGULATION DISORDER

Injury to vessel wall

Exposure to tissue factor on Endothelial cell

TF + VII

TF + VIIaXI XIa

IX IXa

X Xa

Extrinsic Pathway

Intrinsic Pathway

Ca / PL

Ca / PL

Ca / PLVIII VIIIa

Ca / PL

CommonPathway

X Xa

Prothrombin Thrombin

Fibrinogen Fibrin Monomer + Fibrinopeptides

Fibrin PolymerStable FibrinXIII

Ca

Ca / PL

Coagulation Factor1) Factor - I Fibrinogen :-

Level is high 200-400mg/dl

Consist of 3 pair of polypeptide chain

Cleaved by thrombin leaving monomer

2) Factor-II Prothrombin :-

Prothrombin converted to Thrombin by enzyme complex Xa-V-phospholipid-Ca.

3) Factor - III (Thromboplastin) :-

Require for activation of Factor VII in Extrinsic pathway.

4) Factor IV - Calcium,

5) Factor V (Proaccelerin) :-

- Act as a co-factor in conversion of Prothrombin to Thrombin by Prothrombinase complex.

6) Factor VI :-

Activated form of Factor V.

7) Factor VII (Stable factor) :-

Initiate Extrinsic pathway.

8) Factor VIII ( Anti-Haemophilic factor ) :-

- Complex of 2 compound :

a) F VIIIc :- Low Mol. Wt.,

- Pro-coagulant Activity,

b) Von-Willebrand Factor :-

- High Mol. Wt.,

9) Factor IX (Christmas Factor) :-

- Vit. K depending Glycoprotein.

- Activated by F XIa or by F VIIa -

tissue factor complex

10) Factor X (Stuart Prower factor) :-

- Vit. K dependant protein,

- Activated by both, Extrinsic & Intrinsic pathway.

11) Factor XI (Plasma Thromboplastin Antecedent) :-

- Activated by F XIIa in +nce of HMW kininogen,

12) Factor XII (Hageman Factor) :-

- Activated when comes in contact with Collagen,

Glass, Celite,

13) Factor XIII (Fibrin Stabilizing Factor) :-

- Stabilize Fibrin clot by formong intermolecular cross linkage bet. Glutamine & Lysine residue

Primary tests

• Bleeding Time :-

1) Duke’s Method :- Normal range 1 - 5 min.

2) Ivy’s Method :- Normal range 2 - 7 min.

- Sensitive method

3) Standardized Template Method :

- Normal range 2.5 - 9.5 min.

• Coagulation Time :-

1) Dale & Laidlaw’s Method (Capillary Tube Method) :-

• Normal range 4 - 8 mins,

• Insensitive & Nonspecific,

• Clot Retraction Test :-

– Volume of Serum (Blood clotted at 37O C) measured &

expressed as % of Whole blood,

– Normal range 45 - 65 %,

Primary tests

Prothrombin Time

• Principle :-

when the mixture of plasma and tissue

extract (thromboplastin ) are recalcified fibrin

form at normal rate if the factor involved in

extrinsic and common pathway are present in

normal amount.

• Normal Range :- 11-17 sec

Prolonged PT :-

1. Administration of oral anticoagulant drug.

2. Obstructive liver disease.

3. Vit-k deficiency

4. DIC

Prothrombin Time

Activated Partial Thromboplastin Time

• Principle :-

When mixture of plasma ,phospholipid and plate substitute are calcified fibrin form at normal rate only if factor involved in intrinsic and common pathway are present in normal amount.

• Normal Range :- 30- 40 sec

Prolonged aPTT :-1. DIC

2. Liver disease

3. Massive transfusion with stored blood

4. Circulating anticoagulant

5. Administration of heparin.

Activated Partial Thromboplastin Time

Thrombin time

• Thrombin added to plasma & clotting time

measure.

• Affected by

i) Concentration and reaction of fibrinogen.

ii) Presence OF Inhibitory substance.

• RANGE :- 15 – 19 sec

Prolonged in

1. Hypofibrinogenemia found in DIC

2. Raised concentration of FDP found in

DIC or liver disease.

3. Dysfibrinogenemia inherited or acquired

4. hypofibrinogenemia

Thrombin time

Classification of Coagulation Disorder

Inherited coagulation disorder

Acquired coagulation disorder

Inherited Coagulation Disorder

X- linked recessive :- Hemophilia - A Hemophilia - B

Autosomal dominant :- Von-willebrand disease Dysfibrinogenemia

Autosomal recessive :- Factor XI deficiency Prothrombin deficiency Factor v deficiency Factor vii deficiency Factor x deficiency Factor xiideficiency Factor xiii deficiency Afibrinogenemia

Acquired Coagulation Disorder

1. Vitamin k deficiency

2. Liver disease

3. Disseminated intravascular coagulation

4. Anticoagulant drug

5. Acute primary fibrinolysis

6. Massive transfusion of store blood

7. Circulating inhibitor of coagulation

Hemophilia - A

Occur in 1:10000 individual Caused by hereditary deficiency of or

dysfuction of factor viii X- linked recessive The abnormal gene located on x chromosome The disease manifest in only in male. Female are carrier but do not manifest the

disease.

Clinical feature

Fa viii /fa ix level (U/dl)

c/f Hemophilia-A

Hemophilia

B

<1 severe spontaneous

bleeding

70% 50%

1-5 Moderate bleeding with minimal trauma or surgery

15% 30%

6-40 Mild bleeding with mild trauma or surgery

15% 20%

Clinical Features :- Haemarthrosis

- commonly affected joint are knee ankle,

hip & elbow. Subcutaneous & intramuscular hematoma. Gastrointestinal ,genitourinary bleeding Hemorrhage from mouth ,gum ,lip & tongue Traumatic bleeding.

Hemophilia - A

Lab Diagnosis of Hemophilia - A

• PS examination show +nce or -nce of features of anemia.

• BM reflects response to Blood loss,

• Platelet count usually Normal or Elevated,

• aPTT prolonged,

• F VIIIc assays,– Done by :-

• 2 stage method,• One stage method,• Micromethod,

• F VIII Ag assay :-– Highly Specific but, Complicated,– Immunoradiometric method & ELISA technique,

Lab Diagnosis of Hemophilia - A

Hemophilia-B

• Also known as Christmas disease,

• Incidence in 1:60000 population,

• X - linked recessive,

• Less common than hemophilia A,

• Deficiency of factor IX,

• Sign / symptom similar to hemophilia A,

• Specific factor assay necessary to distinguish between Haemophilia A & B

Von-Willebrand Disease

• Van Willebrand factor – synthesized by :-

1) Endothelial cell

2) Megakaryocytes

– Mediate adhesion of platelet to Subendothelium by binding to platelet glycoprotein receptor GpIb & Subendothelium.

– Forms non-covalent complex with F VIII in circulation & prevent degradation and rapid removal of F VIII from circulation.

• Types of bleeding– Mucocutaneous bleeding

– Epistaxis, Menorrhagia, Ecchymoses &

hematomas, gingival &

– GI bleeding

– Soft tissue bleeding (after trauma/injury)

– Dental extraction, wounds, post-operatively,

post-partum

– Results from defect in secondary hemostasis

• Type 1: partial quantitative deficiency of VWF• Of patients with VWD, 73% have Type 1 • Type 2: qualitative deficiency of VWF (21% of VWD patients)• Type 2 variants• VWD Type 2A (synthesis or stability defect)• Decreased platelet dependent function due to loss of large,

functional polymeric forms • high molecular weight multimers [HMWM])• VWD Type 2B (gain of function defect)• Increased affinity for platelet GPIb• VWD Type 2M (“multimer”)• Qualitative defects with decreased platelet dependent function

not caused by• loss of HMWM• VWD Type 2N (FVIII binding defect)• Decreased affinity for FVIII • Type 3: total deficiency of VWF (6% of VWD patients)

Lab Diagnosis in VWD

• Bleeding time - May be Normal in many pts.,• aPTT is prolonged,• F VIIIc assay - Specific,• VWF Immunoassay :

– VWF Ag - measured by Laurell Immunoelectrophoresis method,

– Other Methods - Radioimmunoassay & ELISA,

• Ristocetin Co-factor activity :-– Quantitative Technique for estimating Functional

property of VWF in plasma,

– Most Sensitive & Specific assay,

• Ristocetin Induced Platelet Aggregation :-– Qualitative test,

– Ristocetin + Pts Platelet rich palsma = Aggregation response observed,

Lab Diagnosis in VWD

Disorder of fibrinogen

Quantitative Qualitative

1) Complete absence -afibrinogenemia 1)

2) Low level -Hypofibrinogenemia

Abnormal fibrinogen molecule -Dysfibrinogenemia

Afibrinogenemia

• Autosomal recessive disorder

• Complete absence of fibrinogen in plasma.

• In neonatal period there may be bleeding from umbilical cord.

• Intracranial hemorrhage are common cause of death.

Hypofibrinogenemia

• Autosomal recessive or dominant.• Fibrinogen concentration in plasma less than

100mg/dl.• The condition may be asymptomatic or may

manifest as mild bleeding disorder.•

Dysfibrinogenemia

• Impair fibrin polymerisation

• Impair formation of fibrin clot by interfering in formation of fibrin monomer.

Lab Diagnosis of Afibrinogenemia / Hypofibrinogenemia

• PT, • aPTT, Increased• Thrombin Time,

• Fibrinogen estimation Total absence or

Trace amount

Factor XIII Deficiency

• Inherited as Autosomal Recessive Trait,

• Bleeding occur shortly after birth from Umbilical cord,

• Most life threatening event - Spontaneous Intracranial

Hemorrhage (25 % cases),

• Soft tissue haemorrhages, Hemarthrosis, Hematoma may

occur.

Lab Diagnosis

• PT• aPTT, Normal• Bleeding time,• Platelet count

• Urea Solubility Test (Clot Solubility Test) :- – Clot formed In -nce of F XIII dissolve in urea within min,

– Most useful screening test for F XIII deficiency,

• Quantitative Measurement of F XIIIa • Immunological based assay by ELISA.

Prothrombin Deficiency

• Autosomal Recessive

• Spontaneous hemorrhages - Uncommon,

• Post-traumatic bleeding - MC complaint,

• Bleeding from Umbilical Stump - Common in

infants,

• Specific factor assay used for diagnosis.

Factor V Deficiency

• Autosomal Recessive,• Uncommon,• Epistaxis, Menorrhagia, GIT bleeding,• Inherited form - distinguished from comb. def. of

F V & VII,• Diagnosed by specific assay,

Factor VII deficiency

• Autosomal Recessive,

• F VII level not completely correlate with severity of symptom,

• Pts with level 5 - 10 U / dl,

• Mild symptoms such as epistaxis, GI bleed

• Diagnosis suspected in prolonged PT & normal aPTT,

• Diagnosis by specific Factor assay,

Factor X Deficiency

• Autosomal Recessive,

• Clinical features resembles those of F VII def.,

• Prolongation of PT & aPTT,

• Diagnosed by specific assay

Factor XI Deficiency

• Autosomal Dominant,

• Spontaneous bleeding - Rare,

• Bleeding after Trauma or Surgical procedure,

• aPTT prolonged,

• Diagnosed by Specific assay.

Acquired Coagulation Disorders

Vitamin-K Deficiency

• Fat soluble vitamin

• Required for gamma carboxylation of glutamic acid residues of four vitamin- k dependant factors ii, vii, ix, x

• Post translational modification is essential for binding of these coagulation factor to phospholipid in the presence of calcium.

1. Cause of vitamin k deficiency

2. Haemorrhagic disease of new born.

3. Poor dietary intake.

4. Malabsorption syndrome

5. Obstructive jaundice

DIC

• Characterised by

• 1) Widespread systemic activation coagulation with formation of microthrombi in blood vessels.

• 2)Bleeding diasthesis secondary to depletion of coagulation factor and platelet.

Cause of DIC

1. Obstetric complication

- Abruptio plasenta

septic abortion

IUD

Amniotic fluid embolism

2)Infection

viral-herpes,rubela

bagterial-septicemia

protozoal-malaria

Pathophysiology of DIC

3)neoplasm

prostatic carsinoma

breast carsinoma

lung carsinoma

4)disorder of hemopoietic system

Acut promyelocytic leukaemia

Intravascular hemolysis

5)vascular disorder

Collagen vascular disorder

6)Massive tissue injury

Burn

7)Miscellaneous

Head trauma

snake bite

Clinical featureAcute DIC

Sudden onset of spontaneous bleeding

from multiple site.

Skin - petechiae,ecchymosis

Gastrointestinal bleeding

Hematuria

Epistaxis

Oozing from venepuncture site

Intracranial hemorrhages

Chronic DIC

Manifest usually as venous thrombosis

Laboratory feature

1)P.S. Examination

Fragmented red cells (schistocytes,helmet cells)

Thrombocytopenia

2)coagulation profile

PT

APTT

TT

Level of fibrinogen decreases

Test for fibrinolysis

1)Fibrin degradation product

Acquired Inhibitor Of coagulation

1)Specific

Impair the coagulation by inactivating specific coagulation factor

2)Nonspecific

Interfering with coagulation reaction

Specific

These are antibodies inhibit the activity of specific coagulation factor .

Antibodies against F VII, FIX,FV, FVII,Fbrinogen,von willibrand factor,prothrombin

NonspecificNonspecific

Lupus anticoagulant :-

• Antiphospholipid antibodies that inhibit

coagulation reactions requiring phospholipid.

• These are IgG,IgM

• Interfere with binding of prothrombin and

F Xa to phospholipid

• Prevent the formation of prothrombinase

complex.

These occur in

SLE

Autoimmuno disease

Viral infection (HIV)

Lymphoproliferativ disorder

Drug

C/F

1) Recurrent arterial and venous thrombosis

2)Recurrent spontaneous abortion

3)Intrauterine foetal death

Lab Diagnosis of Lupus Anticoagulant

• ISTH criteria :-– Prolongation of at least one Phospholipid dependant

coagulation test, (e.g. aPTT, Dilute PT, Dilute Russell’s Viper venom time, Kaolin clotting time),

– failure to correct prolonged coagulation time by mixing pts & normal plasma,

– Confirmation of Lupus Anticoagulant by demonstrating correction of prolonged CT by addition excess Phospholipids,

– Exclusion of alternative coagulopathies using specific assay

Other Acquired Coagulative Disorders

• Renal Disease :-– Nephrotic Syndrome:-

• Excessive urinary loss of coagulation factor IX & Antithrombin III,

– Uremia :-

• Haemostatic abn. - defective Platelet function &

- Impairement of Fibrin monomer

polymerisation.

• Amylodosis :-– Deposits in tissue binds F X & causes sec. def.

• Massive Transfusion of Stored blood :-

– Transfusion Pt’s blood volume within 24 hr.

– Usually Deficient in Platelets & coagulation

factors V & VII,

– Dilution of Platelets & coagulation factor.

Other Acquired Coagulative Disorders

Clinical diff between vascular & coagulatio disorder

Parameter Vascular disorder Coagulation disorder

Commonly affected sex

Female Male

Family history Offen negative Offen positive

Petechiae bleeding gum epistaxsis

Common Rare

Deep hematoma & haemarthrosis

Not seen Common

Delayed bleeding Not seen Characteristic

Previous h/o bleeding Not present Present early childhood

Suspected Bleeding Disorder (Repeated bleeding episodes, bleeding from > 1 site, Spontaneous bleeding,)

See nature of Bleeding disorder (Whether Hereditary orAcquired, and Vascular/platelet or coagulation)

Perform screening test (PS, BT, PT, aPTT)

Perform Specific test depending result of screening tests

Specific Diagnosis

aPTT prolonged + PT prolonged

Common Pathway

Thrombin TimeFibrinogen Level

NormalAbnormal

• Common Drugs,• Liver Disease,• Vit. K Deficiency

• Heparin, • Liver disease,• DIC

Reptilase TimeAbnormal Normal

Other Causes Heparin

Acquired Coagulation Disorders