Trombophilia And Thrombosis

Components of Hemostasis • Primary Hemostasis (Platelets &

vWF)

• Coagulation Cascade (Intrinsic & Extrinsic) • Inhibitors of Coagulation (Natural & Acquired) • Fibrinolytic System (Activators, Inhibitors & Degradation products)

Activated partial thromboplastin time (aPTT) Derives its name from use of a partial activated Component like the phospholipid cephalin and Negatively charged substance like kaolin for activation Expressed in seconds with normal range (27-40’’)

Prolonged: Heparin therapy Presence of anticoagulant (lupus like) Factor deficiency Massive blood transfusion. Liver disease High dose coumadin anticoagulation

Factor Inhibitors The mixing study The patient's serum is mixed with normal serum and the aPTT of this mixture is measured. A 50:50 mixture will correct a factor deficiency (only 30% activity is needed for a normal aPTT). In the presence of an inhibitor, a 50:50 mix will not correct the abnormal coagulation test. If inhibition found, additional tests with diluted patient serum and normal serum will be applied and level of inhibitor will be determined (Bethesda units) by the dilution activity Factor VIII inhibitors IgG mostly, Occur primarily in haemophilia A patients who have received blood component transfusions. They develop a severe coagulopathy that is very difficult to manage May occur in a variety of unrelated conditions with a coagulopathy that is variable and usually disappears spontaneously.

Inhibitors of coagulation and fibrinolysis

Half life (hrs)

Chromosome

Function

Protein C

4

2q13-14

Protease (FV&FVIII)

Protein S

42

3p11.1-11.2

APC-cofactor

Thrombo modulin

ND

20p11.2-cen

Receptor for Thrombin/Prot.C

Protein C receptor

ND

20q11.2

Receptor for prot.C/APC

Antithrombin

70

1q23-25

Protease inhibitor

TFPI

ND

2q31-32.1

Protease inhibitor

Heparin Cofactor II

60

22q11

Protease inhibitor

Activation by thrombin or FXa  APC inactivates FVa  FV-Leiden has Gln instead of Arg at 506, which confer APCR 

Protein C pathway

sEPCR

APC

sEPCR

FVIIIa

PC T

sEPCR

FVIIIa

FVa

T TM

PC EPCR

EPCR

APC FVa S

History • • • • • • •

1965 – Antithrombin (Egeberg) 1965 – dysfibrinogenemia (Beck) 1981 - Protein C (Griffin) 1984 - Protein S (Comp) 1993- APCR (Dahlback) 1994 – Factor V Leiden (Bertina) 1996 - PT G20210A mutation (Poort)

Large vessel - Death Medium vessel - Respiratory Failure Small vessel- asymptomatic repetition – pulmonary hypertension

Block

Embolus

Lysed / Organized

Extend

Thrombus

40 35 30

of % VTE among autopsie s

25 20 15 10 5 0

35% 26 % 9 .4%

VTE PE Fatal PE Accountsfor about 10% of deaths in hospitalised patients1 1.Lindblad B, et al. BMJ 1991;302:709–11 2. Dahl OE, Bergqvist D. Curr Opin Pulm Med 2002;8:394–7

Venous Thrombosis Makes News in Washington Surgeon General nominated VTE Task Force

: Inherited Common- )Factor V G1691A )Leiden Prothrombin G20210A               Increased levels of FVIII and               Fibrinogen RareAntithrombin deficiency  Protein C deficiency                Protein S deficiency                Very rare- Dysfibrinogenemia  Homozygous homocystinuria                  ? Future risk factors

:Acquired Trauma or surgery Immobilization Increasing age Malignant disorders Myeloproliferative disorders Previous thrombosis Pregnancy and puerperium Use of contraceptives or HRT Activated protein C resistance Mild to moderate hyperhomocystinemia Antiphospholipid syndrome

‫ב‪.‬א‪ .‬בת ‪ 46‬אושפזה עקב נפיחות וכאבים ברגל‪ .‬באמצעות פלבוגרפיה‬ ‫אובחנה פקקת (‪ )DVT‬והוחל טיפול בהפרין וקומדין‪ .‬במהלך האישפוז‬ ‫תלונות על קוצר נשימה‪ ,‬אובחן תסחיף ראתי‪ .‬אבחנה‪APS :‬‬ ‫כ‪ 10-‬חדשים לאחר מכן אושפזה לניתוח אלקטיבי‪ ,‬הופסק קומדין‪,‬‬ ‫יומיים לאחר הניתוח – קוצר נשימה ‪ -‬תסחיף ראתי‪.‬‬ ‫‪ 5‬שנים לאחר‪ ,‬תלונות על העדר תחושה‪ ,‬בבדיקת ‪ MRI‬נמצאו מוקדים‬ ‫במוח‪.‬‬ ‫‪- Laboratory findings‬‬

‫‪B.E‬‬

‫)‪71” (C. 27-38‬‬ ‫)”‪54” (C. 32‬‬ ‫)‪34 (C < 15‬‬ ‫)‪2.9 (C < 1.3‬‬ ‫‪1.8‬‬ ‫)‪2.14 (C < 1.25‬‬ ‫) ‪1.45 (C > 2‬‬ ‫‪normal‬‬

‫‪Coagulation‬‬ ‫‪aPTT‬‬ ‫‪aPTT mixed with plasma‬‬ ‫‪CAI‬‬ ‫‪RVVT‬‬ ‫‪RVVT confirm‬‬ ‫‪TTI‬‬ ‫‪APCR‬‬ ‫‪Factor V Leiden‬‬

‫‪75u/ml‬‬ ‫)‪(C < 15‬‬ ‫)‪417 u/ml (C < 200‬‬ ‫)‪190 u/ml (C < 50‬‬

‫‪Immunology‬‬ ‫‪anticardiolipin‬‬ ‫‪anti-nuclear ab.‬‬ ‫‪anti-DNA‬‬

 Endothelial

cell mediated: injury to EC, receptor induction, increased TF expression, induction of apoptosis  Protein C pathway related: aPL binds PC&S inhibition of PC activation, acquired APCR  Inhibition of heparin-AT complexes  Cross reaction with OX-LDL  Increase PAI-1  Platelet activation



Clinical criteria

1.Vascular thrombosis )one or more ATE or VTE) 2. Pregnancy morbidity a. one or more IUFD >10th week b. one or more premature birth, preeclampsia, placental insufficiency, abruption, IUGR c. 3 or more early )10th week) abortions,) >2 late) 

Laboratory criteria

1. Anti CL Ab )IgG/M), on two )6w) occasions 2. LAC on two )6w) occasions )aPTT, DRVVT) 3. Exclusion of other coagulopathies Definite aPLS is establish by at least one criterion of each category

Yield (%) 80 70 60 50 40 30 20 10 0

Selected Unselected until 1993

from 1993

Thrombophilia

Healthy subjects

Unselected patients

Selected patients

N

affected %

N

affected %

N

affected %

Protein C

15,070

0.2-0.4

2,028

3.7

880

5.2

Protein S

ND

2,028

2.3

752

7.4

Antithrombin

9,669

0.02

2,028

1.9

752

4.6

Factor V Leiden 16,150

4.8

1,142

18.8

162

40

2,192

0.05

11,932

2.7

2,884

7.1

551

16

1,811

0.06

PT G20210A

Thrombophilia

Healthy subjects

Unselected patients

Selected patients

N

affected %

N

affected %

N

% affected

FVIII

534

11.8

534

23.2

60

56.7

APCR

445

8.1

337

23.4

Hcy

1,153

6.1

856

11.7

Priority for testing High

Intermediate

Low

APCR

Protein C activity

Factor V Leiden

Free protein S antigen Thrombin time

PT G20210A

Antithrombin activity FIX activity

Homocysteine

Anticardiolipin Abs

Factor VIII Lupus anticoagulant

Fibrinogen

FXI activity C677T MTHFR

Risk of recurrence of thrombosis according to type of thrombophilia High

Intermediate Increased

None

Antithrombin

Protein C

FVIII

FVL

APL Abs

Protein S

Hcy

FII

Prothrombin F1+2 and soluble fibrin in normal pregnancy

SSarig )Fertility Sterility 2002(

Gris ( Thromb Haemost )1999

‫‪ ‬בן ‪ ,47‬איש עסקים‪ .‬זמן קצר לאחר הגעתו ארצה‪ ,‬לאחר טיסה‬ ‫של ‪ 18‬שעות מארה"ב‪ ,‬הרגיש כאבים בחזה‪ .‬אובחן כסובל‬ ‫מתסחיף ריאתי‪ .‬ברקע – יתר לחץ דם‪ ,‬מטופל קבוע בתרופות‬ ‫להורדת לחץ דם ואספירין‪ .‬בבירור קרישה‪ ,‬נוגדנים‬ ‫אנטיפוספוליפידים בטיטר נמוך‪ .‬יש לציין שחמש שנים לאחר‬ ‫האירוע ‪ ,‬שוב לקה בתסחיף ריאתי לאחר טיסה‪.‬‬

‫‪31‬‬

A) Cabin related  Cramped sitting position  More in economy class  83% Non-aisle seats  Lower air pressure, relative hypoxia  differ among airlines  Low humidity and dehydration

B) Passenger related Age over 40 Previous VTE Thrombophilia Hormonal Therapy Pregnancy Varicose veins Cancer Overweight

Coagulation activation in hypobaric chamber

Armand Trousseau (1801-1867)

“When you are undecided about the nature of the disease of the stomach, when you hesitate among a chronic gastritis, a simple ulcer, and a carcinoma, a phlegmatia alba dolens (thrombophlebitis) occurring in the leg or arm will put an end to your indecision and you will be able to assert positivelythat a cancer is present.



Endothelial damage • Shift to procoagulant endothelium • Invasion of cancer cells into vessel wall



Stasis of blood • Frequent immobilization, surgery • Compression of blood vessels by tumor



Changes in the blood constituents • Activation of clotting proteins and blood

cells

Tumor Cell Hemostatic Properties and Tumor Biology Tumor cell hemostatic properties Procoagulant Activities Tissue Factor

Fibrinolytic Activities

Mechanisms of malignancy

Coagulationdependent

PROLIFERATION ANGIOGENESIS

(t-PA, u-PA, u-PAR, PAI)

TC-derived Cytokines (IL-1, TNF, VEGF)

Cell Adhesion Molecules

Coagulationindependent

METASTASIS

Tissue Factor/FV IIa Factor Xa

Growth Invasion Metastasis

Thrombin Fibrin generation plays additional roles in Angiogene these processes

Tumor cell

FX TF

Prothrombin

FVIIa FXa

Fibrinogen Thrombin

VEGF

FIBRIN

Angiogenesis TF

Endothelial cells Rickles FR, and Falanga A. Thromb Res 2001

IL-8

Tumour Cell- Host Cell Interactions at The Vascular Site fibrin

Induction of endothelial procoagulant and adhesive properties

Localized clotting activation P P

TC P

P

TC

P P P

TC

Induction of monocyte procoagulant activity

PMN fibrin P TC

Endothelial Cells

TC = tumor cell P = platelet PMN = polymorphonuclear leukocyte

Prandoni, Falanga, Piccioli, Lancet Oncology, 2005

 The

bleeding diathesis of APL is most consistent with the diagnosis of DIC.  Primary fibrinolysis is hard to document in APL and probably does not exist.  Excessive fibrinolysis is probably secondary to thrombin generation.  ATRA can improve the coagulopathy in patients with APL.

Protein C pathway

sEPCR

APC

sEPCR

FVIIIa

PC T

sEPCR

FVIIIa

FVa

T TM

PC EPCR

EPCR

APC FVa S

Acquired activated protein C resistance is common in cancer patients and is associated with VTE

Patients FV Leiden APCR without FV Leiden

Cancer with VTE

Cancer without VTE

VTE without Cancer

Normal Controls

55

58

54

56

1 (2%)

4 (7%)

18 (33%)

2 (4%)

29 (54%)

9 (17%)

7 (19%)

0

Haim, Am J Med 2001

:Heparanase Heparanase activity was implicated in cellular invasion ,angiogenesis, inflammation and cancer metastasis

Heparanase up-regulation was documented in an increasing number of primary solid and hematological .human malignancies Heparanase up-regulation correlated with reduced postoperative survival of pancreatic, bladder, gastric, .cervical and colorectal cancer patients Similarly, heparanase up-regulation correlated with increased lymph node and distant metastases,

Hepa

Hepa Hepa

Heparan sulfate

Considerations in planning treatment of patients with thrombosis • • • •

Efficacy of treatment Rate of bleeding complications Rate of recurrence Complications due to recurrence

 PT

correlates initially with FVII thus not reflecting actual AC  Protein C fast drop creates initial hypercoagulability  Initiation of coumadin should be “covered” by heparin

INR - International Normalized Ratio ISI

INR = R R = PT (sec) patient / PT control example: PT coumadin treated patient - 32 sec, PT control - 12 sec R = 2.6 ISI = international standartization index

Intrinsic pathway

Extrinsic pathway

Antithrombin ATIII

ATIII

Pentasaccharide

ATII I

Xa

Xa

II Fibrinogen

IIa Fibrin clot

Adapted with permission from Turpie et al . N Engl J Med.2001;344:619

ORAL

PARENTERAL TFPI )tifacogin)

TF/VIIa

TTP889 X

IX )APC (drotrecogin alfa )sTM )ART-123

IXa VIIIa Rivaroxab an APIXABAN YM150 DU-176b

Va Xa

AT

Fondaparinux Idraparinux

II

Ximelagatran Dabigatran

DX-9065a IIa Fibrinogen

Fibrin

Adapted from Weitz & Bates, J Thromb Haemost2005