Factor V Leiden – Prothrombin Gene 20210A

Coagulation Medicine for Primary Practitioners

Michael SilveySilvey,, DO Clinical Assistant Professor of Pediatrics Children’s Mercy Hospital/UMKC School of Medicine

Disclosures

. I have nothing to disclose

• Review the basic physiology of the coagulation system

•Understand the proper evaluation of a patient with a possible bleeding disorder

•Accurately interpret specific coagulation laboratory studies

•Discuss clinical manifestations/complications of Hemophilia and other common bleeding disorders

•Discuss inherited thrombophilias

Coagulation System Review

* All numbers Fiscal 2012

X II VIII/vWF TF VIIa Xa Va IIa

TF-Bearing Cell VIIIa

TF VIIa VVVaVa IX Platelet IXa X II

Xa IXa VIIIa Va IIa Activated Platelet

Hoffman M et al. Blood Coagul Fibrinolysis. 1998;9(suppl 1):S61-S65.

Common Pathway

Clot

PT Pathway PTT Pathway

Prothrombin Thrombin

Fibrinogen Fibrin

©2013©2013 Children's Children's Mercy. Mercy. All Rights All Rights Reserved. Reserved. 09/13 09/13 The PT pathway PT Pathway •Only one factor Factor VII involved shorter time •Shorter time  one less letter XV

Prothrombin Thrombin

Fibrinogen Fibrin

The PTT Pathway

Factor XII PTT Pathway Factor XI

Factor IX •More factors more letters and longer time Factor VIII V •Remember by thinking the PTT starts at the top X of the clock! (12)

Prothrombin Thrombin

Fibrinogen Fibrin

. If PT is elevated Factor VII Deficiency is possible . If PTT i s el evat ed  dfiideficienc ies o fFf Fac tors XIIXIIXXII, XI, IX, and VIII . If both are elevated deficiencies of Factors X, V, Prothrombin (II), and Fibrinogen (I)

Evaluation of a Patient with a possible Bleeding Disorder

©2013©2013 Children's Children's Mercy. Mercy. All Rights All Rights Reserved. Reserved. 09/13 09/13 What causes abnormal bleeding? . Trauma . Factor Deficiencies . Antibodies/Inhibitors . Liver Failure . Thrombocytopenia . Vitamin K Deficiency

The bleeding work up

. The most sensitive initial test for a bleeding disorder is an accurate history . Can be difficult – Your idea of bleeding is not my idea . If the patient has a negative history, is asymptomaticand there is a negative family history, no other work up is usually necessary

. Has the patient has significant bleeding? . Is there a family history of bleeding? . What type of bleeding does the patient have?

Type of Bleeding

. Different symptoms may lead you down a different path of why the patient is bleeding – Mucosal bleeding  platelet dysfunction – Muscle/Joint Bleeds factor deficiencies

. Epistaxis . Gingival Bleeding . Menorrhagia . Bruising . Bleeding after dental procedures . Bleeding after surgeries

Have to be Specific!

. Epistaxis – How long? Which Nare? How did you try to stop it? How often? Any trauma? . Menorrhagia – How manyyy days? How man ypy pads/da y? How many heavy/light days? Family History of Menorrhagia?

. If patient has a positive bleeding history next need to do screening labs –CBC . thrombocytopenia –PT/PTT – Fibrinogen – PFA-100

PT/PTT

. Already discussed . Helps determine if there are any factor deficiencies . Can have elevated PT/PTT without having a bleeding disorder

. AKA “Closure Time” . Screening test for platelet dysfunction . Blood is passed through coated membranes with high shear stress . Once the membrane is occludedClosure time

PFAPFA--100100

. Membranes are coated with Collagen/Epi and Collagen/ADP . If first closure time is elevated, then sample is automatically run in the second cartridge

. If both are elevated, then screening test is positive for possible bleeding disorder . If the first is positive and second is normal, then you have “aspirin-induced platelet defect” – Better way of saying this is drug effect

PFAPFA--100100

. Affected by many things – Need to have a certain Hct and plt count – Affected by many drugs (ASA, NSAIDS, antibiotics, cardiac drugs)

. Prolonged PT or PTT – 1:1 Mixing study . Mix patient plasma with normal plasma 1:1 ratio . Run PT/PTT again immediately and after one hour . If PT/PTT normalizes, this indicates factor deficiency . If/PT/PTT remains elevated, something is inhibiting the reaction

Abnormal resultsresults--WhatWhat to do

. Abnormal PFA-100 – Both Col/Epi and Col/ADP are increased . Ensure patient has positive bleeding history . If so, refer to us – Col/Epi increased and Col/ADP normal . Most likely drug effect, make sure patient is not taking anything for at least one week prior to test— re-test if deemed necessary in 1-2 weeks

©2013©2013 Children's Children's Mercy. Mercy. All Rights All Rights Reserved. Reserved. 09/13 09/13 When Abnormal Tests are NOT Bleeding disorders . Elevated PTT – ENT wants to do T&A on a 4yo and ran screening labs prior to surgery – Normal CBC, normal PT, normal PFA-100, but PTT slightly prolonged at 41.1 – Called PCP to have it rechecked and was still elevated at 42.3 one week later

When Abnormal Tests are NOT Bleeding disorders . Elevated PTT – Mixing Study is needed – Results of Mixing Study shows persistent elevation to 40.5 – Patient has a non-specific inhibitor preventing the test from working

©2013©2013 Children's Children's Mercy. Mercy. All Rights All Rights Reserved. Reserved. 09/13 09/13 When Abnormal Tests are NOT Bleeding disorders . Non-specific inhibitors – Common in pediatric population – Usually after having a viral illness – No effect on in vivo coagulation – Can persist for a few weeks

Hemophilia

. Hemophilia A – Factor VIII deficiency – Most cases (~80-85%) . Hemophilia B – Factor IX deficiency . Hemophilia C – Factor XI deficiency

Hemophilia

. X-linked recessive – Except Hemophilia C (autosomal recessive) . Mothers are the carriers . Males usually affected – Can have symptomatic females . Increased PTT – Decreased Factor levels

. One normal gene and one affected gene . Daughter has 50:50 chance of being a carrier . Son has 50:50 chance of having hemophilia

Degrees of Hemophilia

. Mild Hemophilia (5-50%) – Very minor bleeding with trauma and sometimes does not need to have factor replacement . Moderate Hemophilia (1-5%) – Can have severe bleeding after minor trauma . Severe Hemophilia (<1%) – Severe Spontaneous Bleeding anywhere

©2013©2013 Children's Children's Mercy. Mercy. All Rights All Rights Reserved. Reserved. 09/13 09/13 Signs/Symptoms of Hemophilia . Bleeding after circumcision – Can be VERY severe . Difficult to control mouth bleeding . Frequently swollen joints . MltilMultiple Bru ises . Signs of child abuse

Hemarthrosis

. One of the Hallmarks of Hemophilia . Biggest Cause of Morbidity in Hemophiliacs . Acute Bleeding in Joint – Feels Warm – Swelling – Can feel like bubbles in the joint – Marked swelling causes pain – Decreased ROM – Does NOT have superficial bruising initially (very late finding)

Other Major Bleeding Symptoms . CNS Bleeds . Large Muscle Bleeds – Iliopsoas muscle . Leg flexed and internally rotated . Can bleed out into the muscle . Multiple Bruises . Airway compression secondary to bleeding

Hemophilia Treatment

. Factor Replacement . Done for both symptomatic and prophylaxis treatment

. Factor VIII Replacement – 1u/kg increases factor level by 2% . Factor IX Replacement – -1u/kg increases factor level by 1%

Factor Doses

. Major/Life Threatening bleedsreplace 100% – Head Trauma – Neck or Throat Bleeding – Severe muscle/joint bleeds – GI Bleeding . Minor Bleedsreplace 30-50% – Soft Tissue – Nose and Mouth Bleeds

. When giving factor, give the whole vial as to not waste factor . Factor is VERY expensive . If patient has had an injury, ALWAYS give the dose of factor first (ask questions later)

Prophylaxis TreatmentTreatment——WhyWhy?

. Examined giving boys regularly scheduled factor replacement vs. symptomatic care

. Primary outcome was the amount of joint cartilage damage in target joints as detected by radiology

. Receive factor 3-4x a week . 50% correction . All done at home . Usually start when they start moving and when they start having bleeding

Complications of Hemophilia

. Joint damage – Greatly reduced by using prophylaxis . Central line infections – May need central line due to age of child – Accessing line at home . Inhibitor formation

. Immune system develops antibodies against Factor – Up to 25% of Factor VIII deficiency and 2-3% of Factor IX deficiency . Mostly in Severe patients . Very difficult to control bleeding . Treatment is large doses of Factor

Von WillebrandDisease

©2013©2013 Children's Children's Mercy. Mercy. All Rights All Rights Reserved. Reserved. 09/13 09/13 Von WillebrandDisease ((vWDvWD)) . Most common bleeding disorder . Three Types of vWD . Mostly Autosomal dominant – Couple are autosomal recessive

Von Willebrand Factor

. Produced in the endothelial cells and platelets . Very large protein with different parts (multimers) . Acts as a carrier protein for Factor VIII – Without vWF ½ life of Factor VIII is 2hrs . Compared to 12hrs . Helps platelets adhere to damaged endothelium of blood vessels – Stabilizes thrombus and plays a role in fibrinogenesis

. Easy Bruising . Oral Bleeding – (esp after T&A removal and teeth extraction) . Heavy Menstrual Bleeding . Blee ding PiPeri andPd Pos tPt Part um . Bleeding after suturing

vWD diagnosis

. Can be very difficult . vWF is an acute phase reactant . Strict criteria to diagnose vWD – Ristocetin Cofactor Activity <30% AND 1st degree family relative . May take 3-4 lab draws

. CBC . PT, PTT . Factor VIII level . PFA . vWF antigen . Ristocetin Cofactor Activity . Ristocetin induced platelet aggregation

Types of vWD

. Type 1 – Not enough . Type 2 – Have enough, but doesn’t work right . Type 3 – Do not have any at all

. About 75% of cases . Autosomal Dominant . All multimers are present, but all are reduced in quantity . Mild-Moderate bleeding . Ristocetin cofactor activity is low

Type 2 vWD

. Type 2 subclasses – 2A, 2B, 2M, 2N . vWF qualitatively abnormal . Most are autosomal dominant – T2NiType 2N is autltosomal recessive . Type 2B has thrombocytopenia

. No detectable vWF . Autosomal recessive . Very Rare . Severe Bleeding . Can be misdiagnosed as severe Hemophilia A

von WillebrandDisease Treatment . Stimate (Synthetic Desmopressin) – Analog of Antidiuretic Hormone – Stimulates the release of VWF from endothelial cells – Can be give intranasal, Sub Q, or IV – Side effects include Headache, Facial Flushing, hyponatremia – Can cause tachyphylaxis – Stimate is superior to Generic Desmopressin . 15x more concentrated

©2013©2013 Children's Children's Mercy. Mercy. All Rights All Rights Reserved. Reserved. 09/13 09/13 von WillebrandDisease Treatment . Unfortunately some types of VWD will not respond to Stimate . May work well with Type I but can have limited response – Up to 20% do not respond . Does not work for Type 3

. DtkllftfT2Does not work well for most of Type 2 diseases

von WillebrandDisease Treatment . Factor VIII product rich in Von Willebrand Factor

– Humate P

– Alphanate

– Wilate

– Koate-DVI

– All plasma derived with viral inactivation steps in manufacture

. Cryoprecipitate

– Plasma derived—no viral inactivation

. Platelet Transfusion if no other measures are successful

Types of Inherited Thrombophilia

. Gene Mutations – Factor V Leiden – Prothrombin Gene 20210A . Congenital Deficiencies – Protein S Deficiency – Protein C Deficiency – Antithrombin Deficiency

. Point mutation in Factor V Gene . Located at the binding site of Activated Protein C . Protein C cannot bind and cleave activated Factor V . Factor V stays active

Prothrombin Gene 20210A

. Point mutation in the prothrombin Gene . Causes the formation of a longer poly-A tail at the end of the prothrombin mRNA . mRNA is more stable and not degraded . Leads to more prothrombin protein being translated and produced

. Activated protein C inactivates Factor V . Protein S potentiates the activity of Protein C . Deficiencies in either will lead to less cleavage of activated factor V

Antithrombin Deficiency

. Directly inactivates thrombin

©2013©2013 Children's Children's Mercy. Mercy. All Rights All Rights Reserved. Reserved. 09/13 09/13 Prevalence of Inherited Thrombophilias Disorder Prevalence (heterozygote) Risk of Thrombosis- OR (95% CI) FtFactor VLV Le iden 5% o f Caucas ians 3563.56 (2.57 – 4. 93) Prothrombin Gene 20210A 2-7% Europeans 2.63 (1.61 – 4.29) Protein C Deficiency 0.2% 7.75 (4.48 – 13.38) Protein S Deficiency 0.03-0.13% 5.77 ( 3.07 – 10.85) Antithrombin Deficiency 0.02% 8.73 (2.12 – 24.42) Combined deficiencies (≥2) 8.89 (3.43 – 23.06)

Van Ommen, Middeldorp. Semin Thromb Hemost 2011 Young, et al. Circulation 2008

Holzhauer S, et al. Blood 2012

Inherited Thrombophilia

. We do not routinely do thromboprophylaxis on patients with gene mutation . We do not routinely test family members (siblings, children, etc.) if a family member has an inherited thrombophilia

. Testing for inherited thrombophilias is common practice when a patient develops a DVT . Help determine the cause of the thrombosis

Possible Thromboprophylaxis

. Patient has developed infection which needs long term IV antibiotics so PICC line was placed . Developed DVT around PICC line catheter . Tested for genetic mutations and found to have Factor V leiden

. May consider starting patient on some sort of anticoagulation if the patient develops severe illness and needs to have a central line

Conclusions

. Coagulation Cascade can be complicated, but can be simplified so it can be understood

. An accurate history is the most important tool in discovering if a patient has a bleeding disorder

. Coagulation labs tests are helpful in diagnosing bleeding disorders, but they can be abnormal in patients with normal coagulation

. Bleeding complications of hemophilia have been significantly improved with the use of Factor Prophylaxis

. Inherited gene mutations in Factor V and Prothrombin are very common and can lead to increased risk of thrombosis, but the risk is low and we do not recommend testing asymptomatic patients/family members

. ACOP . Drs. Carpenter and Wicklund . Hem/Onc Division at Children’s Mercy Hospital . All of you who have stayed awake listening to me talk about coag

Questions?

. “All blee ding s tops eventually!”

Email: [email protected]