Diagnosis of coagulation disorders

Femela M

Consultant, Pathologist, Kauvery Hospital, Radial Road, Chennai, Tamil Nadu

Introduction

Hemostasis

Hemostasis is the physiological process that stops bleeding, involving a complex interplay of platelets, blood vessels, and coagulation factors.

Formation of hemostatic plug

Primary hemostatic plug	Secondary hemostatic plug
Platelet adhesion: Platelets adhere to endothelium with the help of glycoprotein Ib/IX on platelets and vWF (von Willebrand factor) on endothelium	Coagulation factors normally circulate in plasma in their inactive forms.
Platelet aggregation: Platelets aggregate to each other with the help of glycoprotein IIb/IIIa on platelets	The factors and the other components are assembled on a negatively charged phospholipid surface provided by activated platelets.

Coagulation factors

All factors are synthesized by liver, except factor VIII which is synthesized from endothelium

Coagulation cascade

Facts

Thrombin is called the ‘Master regulator of the coagulation pathway’
Factor Va is called the ‘Fundamental protease of the coagulation system’
K dependent factors are: II, VII, IX, X and anticoagulant proteins – Proteins C, S, Z

Bleeding and coagulation disorders

Disorders of platelets

Quantitative: Thrombocytopenia
Qualitative: Platelet function defect

Disorders of coagulation

Deficiency of coagulation or anticoagulant factors

Excessive fibrinolysis

Disseminated intravascular coagulation
Primary fibrinolysis

Vascular defects

Hypersensitivity vasculitis
Vitamin C deficiency
Amyloidosis
Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease)
Ehlers Danlos disease

Coagulation disorders

Diagnosing coagulation disorders involves a systematic approach integrating clinical evaluation with laboratory testing to determine abnormalities in hemostasis.
Coagulation disorders can be congenital or acquired, and they affect the body’s ability to form blood clots effectively, which may result in bleeding or thrombotic complications.

Vitamin K deficiency or warfarin	Hypofibrinogenemia/Afibrinogenemia
Disseminated intravascular coagulation	Factor V deficiency
Hemophilia	Factor X deficiency
Von Willebrand disease	Glanzmann's thrombasthenia
Liver failure	Bernard–Soulier syndrome
Uremia	Factor XI deficiency
Antiphospholipid antibody syndrome	C1INH deficiency

Interpretation

Clinical differences between disorders of platelets/vessels and coagulation

Characteristics	Platelet/vessel disorders	Coagulation disorders
Petechiae	Common	Rare
Hematomas	Rare	Common
Ecchymoses	Characteristic: small and multiple	Common: large and solitary
Hemarthrosis	Rare	Characteristic
Sex of patient	F >> M	M >> F
Family history	Rare (except vWD)	Common

Normal values

PT (Prothrombin time) = 11 to 13.5 seconds
aPTT (activated Partial Thromboplastin time) = 26 to 40 seconds
TT (Thrombin time) = 15 to 19 seconds (or) within 2 seconds of the control
Plasma fibrinogen = 1.8 to 3.6 g/l
Platelet count = 1.5 to 4.1 lakh / mm³

Interpretation

S. No	PT	aPTT	TT	Fibrinogen	Platelet Count	Condition
1	N	N	N	N	N	1. Normal hemostasis 2. Disorder of platelet function 3. Factor XIII deficiency 4. Disorder of vascular hemostasis 5. Mild/masked coagulation factor deficiency 6. Mild von Willebrand disease 7. Disorder of fibrinolysis

S. No	PT	aPTT	TT	Fibrinogen	Platelet Count	Condition
2	Long	N	N	N	N	1. Factor VII deficiency 2. Early oral anticoagulation 3. Lupus anticoagulant 4. Mild II, V, or X deficiency’s

S. No	PT	aPTT	TT	Fibrinogen	Platelet Count	Condition
3	N	Long	N	N	N	1. Factor VIII, IX, XI, XII, prekallikrein, HMWK deficiency 2. Von Willebrand disease 3. Circulating anticoagulant eg. Lupus 4. Mild II, V, or X deficiency

S. No	PT	aPTT	TT	Fibrinogen	Platelet Count	Condition
4	Long	Long	N	N	N	1. Vitamin K deficiency 2. Oral anticoagulants 3. Factor V, X, or II deficiency 4. Multiple factor deficiency eg. Liver failure 5. Combined V + VIII deficiency

S. No	PT	aPTT	TT	Fibrinogen	Platelet Count	Condition
5	Long	Long	Long	Normal or abnormal	N	1. Heparin 2. Liver disease 3. Fibrinogen deficiency / disorder 4. Inhibition of fibrin polymerization 5. Hyperfibrinolysis

S. No	PT	aPTT	TT	Fibrinogen	Platelet Count	Condition
6	N	N	N	N	N	Thrombocytopenia

S. No	PT	aPTT	TT	Fibrinogen	Platelet Count	Condition
7	Long	Long	N	Normal or abnormal	Low	1. Massive transfusion 2. Liver disease

S. No	PT	aPTT	TT	Fibrinogen	Platelet Count	Condition
7	Long	Long	Long	Low	Low	1. Disseminated intravascular coagulation 2. Acute liver disease

Case Scenarios

Case 1

A newborn baby was brought to the neonatologist with H/O. delay in umbilical cord separation

Sl. No.	Parameter	Value	Reference range	Unit
1	PT	11	11 to 13.5	Seconds
2	INR	1.0	0.8 to 1.2
3	aPTT	34	26 to 40 seconds	Seconds
4	TT	16	15 to 19 seconds	Seconds
5	Plasma Fibrinogen	2.9	1.8 to 3.6	g/l
6	Platelet count	3.1	1.5 to 4.1	Lakhs / mm3

Diagnosis

Factor XIII deficiency

Discussion

Rare bleeding disorder
Factor XIII, a protein crucial for stabilizing blood clots
Manifest as either a congenital (inherited) or acquired condition
Symptoms can range from mild to severe and include delayed umbilical cord separation, easy bruising, nosebleeds, heavy menstrual bleeding, and in severe cases, life-threatening intracranial hemorrhages

Case 2

A 69 old male, a k/c/o. coronary artery disease.
Recently underwent stent placement
On T. Acitrom

Sl. No.	Parameter	Value	Reference range	Unit
1	PT	24	11 to 13.5	Seconds
2	INR	2.1	0.8 to 1.2
3	aPTT	31	26 to 40 seconds	Seconds
4	TT	16	15 to 19 seconds	Seconds
5	Plasma Fibrinogen	2.3	1.8 to 3.6	g/l
6	Platelet count	1.8	1.5 to 4.1	Lakhs / mm3

Treatment

Prolonged PT, correlates with drug therapy and is within therapeutic range

Case 3

months old male presents to the OPD with hematoma on the back
H/O. bleeding after vaccination present
Maternal uncle has similar clinical history

Sl. No.	Parameter	Value	Reference range	Unit
1	PT	12	11 to 13.5	Seconds
2	INR	1.1	0.8 to 1.2
3	aPTT	56	26 to 40 seconds	Seconds
4	TT	15	15 to 19 seconds	Seconds
5	Plasma Fibrinogen	2.0	1.8 to 3.6	g/l
6	Platelet count	3.9	1.5 to 4.1	Lakhs / mm3

Mixing study: aPTT prolongation is corrected

Diagnosis

Hemophilia

Hemophilia

Hemophilia is a rare genetic bleeding disorder that prevents blood from clotting properly
This happens due to a deficiency or defect in factor VIII
X-linked recessive disorder; hence manifests in males and females are carriers.

There are two major types of inherited hemophilia:

Hemophilia A (classic hemophilia): Caused by a lack of or reduced amount of clotting factor VIII
Hemophilia B (Christmas disease): Caused by a lack or decrease of clotting factor IX

Case 4

40/M presents with deep vein thrombosis in the left leg
No comorbidities
Similar history presents in father.

Sl. No.	Parameter	Value	Reference range	Unit
1	PT	21	11 to 13.5	Seconds
2	aPTT	58	26 to 40 seconds	Seconds
3	TT	16	15 to 19 seconds	Seconds
4	Plasma Fibrinogen	2.7	1.8 to 3.6	g/l
5	Platelet count	3.4	1.5 to 4.1	Lakhs / mm3

Further evaluation confirmed

Activated protein C resistance and
Leiden mutation

Prolonged PT as well as aPTT, resistance to activated protein C and the DNA test confirm factor V Leiden mutation

Case 5

A 72-year-old male presents to the Emergency Department with following complaints

Unconscious
Icterus +
Ascites +

Clinical diagnosis: Hepatic encephalopathy

Sl. No.	Parameter	Value	Reference range	Unit
1	PT	22	11 to 13.5	Seconds
2	aPTT	49	26 to 40 seconds	Seconds
3	TT	35	15 to 19 seconds	Seconds
4	Plasma Fibrinogen	2.3	1.8 to 3.6	g/l
5	Platelet count	4.1	1.5 to 4.1	Lakhs / mm3

Treatment

Prolonged PT, aPTT as well as TT, compatible with liver disease

Advances in diagnosis of coagulation disorders

Equipments used for diagnosing coagulation disorders

1. Coagulation analyzer tests

Prothrombin time (PT)
Activated partial thromboplastin time (aPTT)
Thrombin time
Fibrinogen estimation

2. Immunoassay analyzer

D-dimer test

3. Point of care devices for coagulation tests

4. Factor assay: (Estimation of coagulation factor levels in plasma), Mixing study

5. Thromboelastography: Helps assess bleeding and thrombotic risks and also monitor the effect of antithrombotic therapies.

References

Hoffbrand’s Essential Hematology, 9^th
Essential Guide to Blood Coagulation by Jovan P. Antovic, Margareta Blombäck, 2013
Coagulation Disorders: Quality in Laboratory Diagnosis (Diagnostic Standards of Care) by Laposata, Michael
Coagulation Disorders – Innovative Developments in Diagnostic and Therapeutic Approaches by Cees Th. Smit Sibinga
Clinical Laboratory Hematology by Mc Kenzie.

Kauverian Bookshelf

Applied Medical Statistics

Diagnosis of coagulation disorders