Protein C, Protein S and anti-thrombine deficiency

1. Welcome
TOPIC PRESENTATION
ON
THROMBOPHILIA

2. Presented by
Dr. Md. Nazmul Hassan
Resident, Year 3
Paediatric gastroenterology & Nutrition

3. Introduction
• Thrombophilia (sometimes hypercoagulability or a
prothrombotic state) is an abnormality of blood coagulation
that increases the risk of thrombosis (blood clots in blood
vessels)
• The first major form of thrombophilia, antithrombin
deficiency, was identified in 1965, while the most common
abnormalities (factor V leiden mutation) were described in
the 1990s.

4. Thrombophilia
Congenital
1. Factor V leiden
mutation
2. Prothrombin mutation
3. Deficiency of protein
C, S & anti-thrombin-III
4. Factor VIII mutation
5. Familial
dysfibriginemia
Acquired
1. Anti-phospholipid
syndrome
2. Myelo-proliferative
disorder
3. Nephrotic syndrome
4. Sickle cell disease
5. PNH etc.
Unclear

5. Overview
• Introduction
• Epidemiology
• Patho-physiology
• Classification & Function
• Clinical presentation
• Evaluation and diagnosis
• Management

6. Protein C deficiency

7. Protein C deficiency
• Protein C is a vitamin K dependent anticoagulation protein,
synthesized in the liver having molecular weight of about 62
KD and consist of two chains connected by disulfide bridge.
• Inherited protein C deficiency is an autosomal dominant
disorder & most are heterozygous.

8. Epidemiology
The incidence of inherited protein C deficiency varies depending
on the population:
• Healthy individuals in the general population – Approximately
0.2 to 0.5 percent.
• Individuals with venous thromboembolism (VTE) –
Approximately 2 to 5 percent.

9. • Protein C circulates in human plasma at an average
concentration of 4 mcg/mL.
• In healthy adults with 95 percent of the values ranging
between 70 - 140 percent of normal.
• There is no significant sex difference.

10. After birth, levels of protein C take some time to reach normal
adult levels.
• 7-18 % of normal
Preterm infants
• 20-40% of normalTerm infants

11. Pathophysiology

12. Blood coagulation pathway

13. Protein C activation
Protein C circulates as a zymogen and exerts its anticoagulant function after activation to
activated protein C (aPC), a serine protease
when thrombin bind with the endothelial cell receptor thrombomodulin ln
vascular endothelium
Synthesis of gamma-carboxyglutamic acid (Gla) in protein C
Gla binds with Calcium leading to structural changes facilitates Phospholipid
bindings important for functional activation
Vitamin K

14. Protein C activation

15. Function of protein C
Anti Inflammatory
effect

16. Classification of Protein C
Inherited Protein C
deficiency
Type I deficiency
Reduced level due to
mutation (missense
or nonsense )
Type II deficiency
Reduced function
with normal level
Type I deficiency is more common than Type II deficiency

17. Causes of reduced protein C level
A. Genetic mutation Causes of increase Protein C level
B. Acquired causes:
I. DIC
II. Liver disease
III. Acute insults to liver like RHF with
hepatic congestion
IV. Infection- Meningococcemia, Malaria
V. Uremia (less activity)
VI. Cancer or cancer chemotherapy-
asparaginase
VII. Drugs: Vitamin K antagonist
(warfarin)
VIII. Vitamin K deficiency- Severe
malnutrition, antibiotic use
IX. Autoantibodies
I. Nephrotic syndrome
II. Hyperlipidaemia
III. Normal aging
These conditions transiently reduce protein C levels, typically modest, and these patients
generally should not be considered to have protein C deficiency for diagnostic or therapeutic
purposes except patient with purpura fulminans and DIC in acute meningococcemia

18. Clinical manifestation

19. 1. Venous thromboembolism:
The risk of thrombosis with heterozygous protein C deficiency is
increased approximately 07- fold.
Individuals with protein C deficiency can develop venous
thromboembolism (VTE) at any site. Most commonly in: thrombosis in the
deep veins of the leg (DVT), mesenteric veins, and pulmonary embolism (PE)
are the.
Other sites include: Cerebral veins, Portal vein, Superficial or other unusual
sites.
Other risk factors are:
1. Family history of VTE
2. Factor V leiden mutation
3. Prolong immobility
4. Surgery
5. Oral contraceptive use
6. H/O recurrent VTE

20. 2. Neonatal purpura fulminans:
Purpura fulminans in newborns is a rare, life-threatening condition
characterized by disseminated intravascular coagulation (DIC), extensive
venous and arterial thrombosis, and hemorrhagic skin necrosis.
3. Arterial thrombosis/ stroke
4. Fetal loss in pregnancy:
Pregnancy increases the risk of VTE due to a number of physiologic
and anatomic changes, and prophylactic anticoagulation during pregnancy
and the postpartum period to reduce the risk of VTE is appropriate for certain
individuals with protein C deficiency

21. Protein S deficiency

22. • Protein S is a 71-kDa vitamin K dependent glycoprotein but it is
not a zymogen (serine protease enzyme) like protein C.
• It is primarily synthesize in Hepatocytes, but it can be
produced from endothelial cells and megakaryocytes.
• It is named for Seattle, Washington where it was originally
discovered.
• Inherited protein S deficiency is an autosomal dominant
disorder & most are heterozygous.

23. Epidemiology
 Protein S deficiency is inherited as an autosomal-dominant
manner and has a prevalence of 1:33,000.
 According to Multiple Environmental and Genetic Assessment
of risk factors for venous thrombosis in patient with VTE the
approximately 48 of 5317 (0.9 percent).
 Earlier studies had reported frequencies of protein S
deficiency in the range of 2 to 8 percent among individuals
with VTE.

24. • The average plasma concentration of total protein S in adults
is 23 mcg/mL.
• Total protein S levels change with age, but free protein S
levels are more constant.
• Total protein S levels in healthy newborns at term are 15-30%
of that in adults, while C4b-binding protein is markedly
reduced to less than 20 %.
• Protein S levels increase with advancing age and protein S
levels in men were approximately 10-20% higher than in
women.
• Serum lipids may affect (increase) protein S levels.

25. Mature γ-carboxylated
protein S
Free form
30-40% of total S
Has only cofactor activity for protein C
Bound to complement
component (C4b-BP)

26. Pathophysiology

27. Protein S activation
when thrombin bind with the endothelial cell receptor
thrombomodulin ln vascular endothelium
Synthesis of gamma-carboxyglutamic acid (Gla) in
protein S
Vitamin K

28. Function of protein-S
• It also directly
inhibit prothrombin
activation via
interactions with
other coagulation
factors.

29. Classification of Protein S deficiency
Inherited Protein S
deficiency
Type I deficiency
Reduced level due to
mutation (missense or
nonsense )
Type II deficiency
Reduced function with
normal total & free
Protein S level
Type III deficiency
Total S normal
Selectively reduced
free protein S &
protein Function

30. Causes of reduced protein S level
A. Genetic mutation
B. Acquired causes:
I. DIC
II. Liver disease
III. Infection- During VZV infection recovery (transient due to
autoantibody formation against Protein S in renal and
spermatic vein thrombosis)
IV. Cancer or cancer chemotherapy: L-asparaginase
V. Drugs: Vitamin K antagonist (warfarin), OCP
VI. Pregnancy
VII. HIV infection
VIII. Nephrotic syndrome ( ↑ Total protein but reduced
function)

31. Clinical manifestation

32. 1. Venous thromboembolism:
Most common site are: thrombosis in the deep veins of the
leg (DVT) and pulmonary embolism (PE).
Other sites include: Cerebral veins, Mesenteric vein, Axillary vein, Calf vein,
Intra-cardiac vein.
In a 2013 meta-analysis of studies involving patients with portal vein
thrombosis (PVT) or hepatic vein thrombosis (Budd-Chiari syndrome [BCS]),
inherited protein S deficiency was found in 3%.
Other risk factors are:
1. Family history of VTE
2. Prolong immobility
3. Surgery
4. Oral contraceptive use
5. Chemotherapy

33. 2. Neonatal purpura fulminans:
Purpura fulminans in newborns is a rare, life-threatening condition
characterized by disseminated intravascular coagulation (DIC), extensive
venous and arterial thrombosis, and hemorrhagic skin necrosis.
3. Arterial thrombosis/ stroke: 2-3%
4. Obstetrical complications:
Miscarriage
5. Warfarin induced skin necrosis

34. Antithrombin III deficiency

35. • Antithrombin III (Heparin cofactor-I protease) is a nonvitamin K-
dependent natural anticoagulant.
• AT deficiency is autosomal dominant with variable penetrance.
• Antithrombin III activity is markedly potentiated by heparin (1000
fold) due to a conformational change leading to enhanced exposure
of the reactive center in AT induced by heparin binding.
• AT-III is an alpha-2-globulin with a molecular weight of 58,000 to
65,000 daltons that is synthesized primarily by the liver.

36. Epidemiology
 The estimated prevalence in the general population is thought
to be in the range of 0.2 to 0.6% (1 in 5000 to 1 in 500
individuals).
 Deficiency is equally common in both sexes.
 In individuals with VTE the prevalence is estimated to be
approximately 1 to 7%.

37. • The reference range of antithrombin-III varies by age, as
follows:
Newborn: 60%-90%
Children and adults: 80%-120%
• Plasma concentration: 0.15-0.2 mg/mL
• The half-life of AT is approximately 2.8 to 4.8 days.
• Healthy newborns have approximately 50 % AT activity, this
reaches adult levels by approximately six months of age.

38. Pathophysiology

39. Antithrombin III activation
• Activated Antithrombin III is a major inhibitor of thrombin and
factor Xa, with smaller effects on factor IX, XI & XII.
• Binds to the endothelial cell surface in the presence of injury.
• Forms a subendothelial cell matrix that neutralizes thrombin
by complexin with it.
• Serves as a cofactor for exogenous heparin.

40. Function of Antithrombin III

41. Classification of Antithrombin III deficiency
Inherited Antithrombin III
deficiency
Type I
deficiency
Type II
deficiency
Reactive site
defect (type II
RS)
Heparin binding
site defect (type
II HBS)
Pleiotropic
effect mutations
(type II PE)

43. Causes of Antithrombin III deficiency
A. Genetic mutation or other alteration (deletion)
B. Acquired causes:
I. DIC
II. Liver disease (primarily cirrhosis)
III. Acute thrombosis (transiently)
IV. ECMO and haemodialysis
V. Cancer or cancer chemotherapy: L-asparaginase
VI. Nephrotic syndrome

44. Clinical manifestation

45. 1. Venous thromboembolism
The most common sites are:
the deep veins of the leg,
the iliofemoral veins and
the mesenteric veins
Other site includes (Less frequently):
the vena cava and the renal, retinal, cerebral, or hepatic
veins (Budd-Chiari syndrome)
Patients with AT deficiency appear to be at particularly high risk
of thrombosis during pregnancy.
2. Arterial thrombosis/stroke
3. Renal insufficiency due to fibrin thrombi in kidneys
4. Heparin resistance

46. Diagnostic evaluation

47. Protein C deficiency Protein S deficiency Antithrombin III deficiency
1. Recurrent venous
thrombosis
2. Thrombosis in an unusual
vascular bed (eg, portal,
hepatic, mesenteric,
cerebral)
3. Thrombosis at a young
age (eg, <50 years),
4. Strong family history of
venous VTE, and/or
5. Warfarin-induced skin
necrosis.
1. Strong family history of
VTE
2. Known familial protein S
deficiency
3. First VTE event before
age 50
4. VTE in an unusual site
such as portal,
mesenteric, or cerebral
vein
5. Recurrent VTE
1. Suspected inherited
thrombophilia (eg, based
on family history or
atypical presentation)
2. Children with
thromboembolism in the
absence of a central
venous catheter
3. Suspected heparin
resistance
4. Asparaginase therapy or
extracorporeal
membrane oxygenation
Indication for testing

48. Investigation
1. Detection of plasma level of protein C, Protein S &
Antithrombin III.
Deficiency
Protein C
deficiency
< 65-70% than
normal (50%)
Protein S
deficiency
No ideal cut off
value
Like Protein C
Antithrombin III
deficiency
< 80% of normal
(80-120%)

49. Timing of testing
• Acute thrombosis, acute inflammatory condition, liver
disease, pregnancy, and any comorbid illness that causes an
acute phase response can lower the level of free protein S,
resulting in erroneous diagnosis of protein S deficiency.
• Vitamin K antagonists (Warfarin) can cause reduced protein S
levels, it is preferable to perform testing at least two weeks
after the last dose of the VKA. If it is not possible to
discontinue the VKA for clinical reasons, it may be possible to
transition the patient to heparin or low molecular weight
(LMW) heparin prior to testing.

50. Treatment

51. • VTE patient with inherited thrombophilia: Anticoagulation therapy
with either:
Low molecular weight heparin
Warfarin
Direct oral anticoagulant (DOAC) [edoxaban,
rivaroxaban, dabigatran]
Combination of both heparin & warfarin during
first several days of warfarin administration.
Duration: Usually 03-06 months but Indefinite anticoagulation is
recommended for patients with an unprovoked thromboembolic
event, or if there is a strong family history of VTE. Other factors more
likely recurrent thrombosis, life-threatening thrombosis, thrombosis
at an unusual site, or more than one inherited prothrombotic defect.
If severe form of deficiency presents, then
1. Protein C concentrate (Ceprotin)
2. FFP

52. • Individuals with protein C, S & Antithrombin III deficiency may
need judicious use of prophylactic anticoagulation in certain
settings, especially if they have a strong family history of
thrombophilia or other VTE risk factors

54. Dose of warfarin therapy
1. 2 mg daily for the first three days followed by gradually
increasing increments of an additional 2 to 3 mg until
therapeutic anticoagulation is achieved.
2. According to Age and INR:
INR Dose Therapeutic range
Initially started with 0.2mg/kg, then 2-3 (mean 2.5)
1.1-1.4 ↑ 20%
1.5-1.9 ↑ 10%
2-3 No change, same dose
3.1-3.5 ↓ 10%
> 3.5 Hold until <3.5 & restart
at 20% ↓ dose

55. F/Up and contraindication
If acute condition:
Low molecular weight heparin should started for at least 5 day
followed by warfarin when INR > 2.0 at least consecutive two days.
F/UP:
1. Meticulously f/up with PT with INR and Platelet count.
2. F/UP with INR: Every weekly, if given indefinate period of life long
then, 03 monthly.
Contraindication:
 Aspirin, Ibuprofen, herbal medicine.
 Warfarin should be stopped 5 days before any major surgery &
started 12-24 hours post –operatively.

56. Rx of complication
1. Warfarin induced skin necrosis:
•Discontinue warfarin.
•Administer vitamin K intravenously.
•Administer unfractionated heparin
•Administer a source of protein C such as protein C
concentrate (eg, Ceprotin, not available in all centers) or
Fresh Frozen Plasma (FFP)
2. Neonatal purpura falminants:
Protein C concentrate (ceprotin of FFP)