Bleeding DisordersVascular and Platelet Disorders

Ahmad Shihada Silmi Msc,FIBMS

IUG Medical Technology Dept

Bleeding Disorder Terms

Petechiae-pinpoint size/pinhead size hemorrhagic spots in skin Purpura-hemorrhage under the skin, varying in color and duration Ecchymosis-purplish patch caused by extravasation of blood into skin,

larger than petechiae Epistaxis-nosebleed Menorrhagia-excessive menses Hematuria-blood in urine Hemarthrosis-bleeding into joint Hematemesis-vomiting blood Hemoptysis-spitting blood Melena-blood in stool (occult blood)

Bleeding disorders

Vascular abnormalities

Platelet disordersClotting factorabnormalities

DIC

Vessel Defects Causing Bleeding

Begins with bleeding episode in presence of normal lab tests for coagulation function

Types divided into hereditary and acquired Symptoms are usually of the superficial ones. Usually these diseases are diagnosed by exclusion.

After ruling out PLT disorders, coagulation or fibrinolytic disorders in a patient who has bleeding symptoms.

Vascular Diseases

PLT count and screening tests for coagulation factors are usually normal.

PLT function tests such as bleeding time and other PLT function tests are also normal, but BT may be prolonged in some vascular diseases.

They are very rare, and while bleeding is a common symptom, hemostasis tests are NOT necessary for diagnosis.

Inherited vascular disorders

Hereditary Connective Tissue Defects

Defect affects ability to support vessel walls Examples

– Ehlers-Danlos Syndrome Lack of structural tissue support (collagen disorders) Skin elasticity and fragility. Hypermobility of joints Evidenced by bleeding/bruising Recurrent joint problems & scarring of the face. The most serious is deficient of type III collagen (blood

vessel type). Which leads to Acute & sever Internal bleeding & sudden death.

Hereditary Connective Tissue Defects

Pseudoxanthoma Elasticum– Autosomal recessive trait– Lack of skin elasticity– Some connective tissue calcified– Bleeding and bruising evident

Hereditary Vessel Disease

Hereditary Haemorrhagic telangiectasia (HHT) Inherited as autosomal dominant trait Defect of angiogenesis Involves bleeding from abnormally dilated vessels

“telangiectasias” Vessels involved do not contract normally and collapse easily Patient has pinpoint lesions (tiny areas of bleeding) Lesions occur on face, hands and feet May develop at all ages Blood loss may cause anemia Diagnosis based on physical appearance

Hereditary Vessel Disease

Kasabach-Merritt syndrome (Hemangioma)

Benign tumour of vascular tissue Grow rapidly to giant proportion. Threaten the function of neighbouring tissues. Mechanical injury may result in sever bleeding. May trigger a localized DIC with thrombocytopeia &

consumption coagulopathy, thereby worsening bleeding.

Tumor composed of many blood vessels (blood-filled)

Hereditary Vessel Disease

HHT or also called Cavernous Hemangioma Lesion may swell and bleed Tumor site may form clots, hemolyzed RBCs and

vessel obstruction Present at birth Treatment is by surgical removal, if possible,or

localized radiotherapy with injection of fibrinolytic inhibitors.

Are seen quite often.

Are characterized by bruising and petechiae

Acquired Vascular Disorders

Acquired Connective Tissue Defects

Vitamin C Deficiency (Scurvy) Caused deficient Vitamin C Vitamin C required for vessel collagen integrity Acts as “cement” holding endothelial cells together Lack of Vitamin C prevents proper collagen formation Result: bleed and vessel fragility Symptoms include gum bleeding, petechiae and

bleeding into tissues and muscles Treated with Vitamin C

Acquired Connective Tissue Defects

Senile PurpuraOccurs in elderly populationUsually benignCollagen degradation/loss affects vessel

integrityBruising on arms/handsNo treatment/therapy available

Due to abnormal proteins in the vascular system

Paraproteins are monoclonal Ig produced by a single clone of plasma cells.

Also called M component.

These paraproteins occur in MM, WM, and lymphoproliferative disorders.

Purpura due to Paraproteins

Symptoms: purpura, bleeding and thrombosis. The defect is related to multifactors:

– Qualitative PLT defects.– Acquired inhibitors.– Deficiency in coagulation factors.– Paraproteins binds Ca, Ca either will not be

available for coagulation or the Ca bounded paraproteins will interfere with coagulation.

– Thrombocytopenia.

Purpura due to Paraproteins

Cont’d

Bleeding symptoms include:– Epistaxis– Petechiae,– Purpura, and– Retinal bleeding.

Purpura due to Paraproteins

Cont’d

Amyloidosis Occur as primary disease or is associated

with paraproteinemias. Deposition of amyloid on skin and

vascular walls. Leads to fragility of vessel walls.

Purpura due to Paraproteins

Other Vascular Disorders

Self-produced “autoantibodies” damage to vessels Caused by drugs resulting in purpura Caused by allergic/immune disturbance

Evidenced by swelling, ulcers, purpura and lesions and other symptoms

Affects children Other allergic purpura-Hemoch-Schonlein variety

Accompanied by joint and abdominal pain Avoidance of allergen aids recovery

Other Vascular Disorders

Infectious purpura Observe petechiae and purpura Results from

Inflammatory response to agent Autoimmune/autoantibody response Bacterial products or toxins Injury caused by agent

Low platelets observed and DIC Cure is to treat infection

Bleeding disorders

Vascular abnormalities

***Platelet disorders

Clotting factorabnormalities

DIC

Platelet Disorders Classification:

Thrombocytosis

Thrombocytopathy

Thrombocytopenia

PLT Reference Range = 150 - 450 x109/L

Qualitative PLT Disorders

Quantitative PLT Disorders

Thrombocytosis

Thrombocytosis resulting from myeloproliferation– essential thrombocythemia– polycythemia vera– chronic myelogenous leukemia– myeloid metaplasia

Secondary (reactive) thrombocytosis– systemic inflammation– malignancy– iron deficiency– hemorrhage– postsplenectomy

Thrombocytopenia

Reduced platelet count.

The most common cause of excess or abnormal bleeding.

As anemia is a symptom of a disease as we have seen in Hematology #1, thrombocytopenia is also a symptom of a disease!

Do not forget to assure that the case you have is a real thrombocytopenia

and not PseudothrombocytopeniaPlatelet

clumping, or aggregation

Platelet Satelltism

Pseudothrombocytopenia

Platelet countSymptoms

50-100 X109/LProlonged bleeding following trauma

< 50X109/LEasy bruising

Purpura following minor trauma

< 20 X109/LSpontaneous bleeding

Petechiae

May suffer spontaneous internal and intracranial bleeding

Thrombocytopenia

Hemostatic Level

Hemostatic Platelet count level is more than 50 x109/L.

This means that normal hemostasis may occur ≥ 50 x109/L

Classification: platelet disorders

Thrombocytopenia

Causes

Impaired or DecreasedProduction

Distribution/Dilution Disorders

Increased Destruction

Megakaryocyte aplasia

BM Replacement

Ineffective poiesis

Immune Non-Immune

General characteristics of platelet disorders

characterized by variable mucocutaneous bleeding manifestations.

excessive hemorrhage may follow surgical procedures or trauma.

Platelet counts and morphology are normal. prolonged bleeding time, Abnormal Platelet aggregation and secretion

studies

Thrombocytopenia

Usually mucosal bleeding Epistaxis, menorrhagia, and GI bleeding is

common Trauma does not usually cause bleeding

Thrombocytopenia

Three mechanisms of Thrombocytopenia– Decreased production

Usually chemotherapy, myelophthisic disease, or BM effects of alcohol or thiazides

– Splenic Sequesteration Rare Results from malignancy, portal hypertension, or

increased Splenic RBC destruction ( hereditary spherocytosis, autoimmune hemolytic anemia)

– Increased Destruction

Thrombocytopenia

Immune thrombocytopenia– Multiple causes including drugs, lymphoma, leukemia,

collagen vascular disease– Drugs Include

Digitoxin, sulfonamindes, phenytoin, heparin, ASA, cocaine, Quinine, quinidine, glycoprotein IIb-IIa antagonists

– After stopping drugs platelet counts usually improve over 3 to 7 days

– Prednisone (1mg/kg) with rapid taper can shorten course

Thrombocytopenia

HIT– Important Immunologic Thrombocytopenia– Usually within 5-7 days of Initiation of Heparin

Therapy but late onset cases are 14-40 days– Occurrence 1-5% with unfractionated heparin

and less than 1% with low molecular-weight heparin

– Thrombotic complications in up to 50% of HIT with loss of limb in 20% and mortality up to 30%

ITP

Diagnosis of exclusion Associated with IgG anti-platelet antibody Platelet count falls to less that 20,000

ITP

Acute Form– Most common in children 2 to 6 years– Viral Prodrome common in the 3 weeks prior– Self Limited and > 90% remission rate– Supportive Treatment– Steroids are not helpful

ITP

Chronic Form– Adult disease primarily– Women more often than men– Insidious onset with no prodrome– Symptoms include: easy bruising, prolonged

menses, mucosal bleeding– Bleeding complications are unpredictable– Mortality is 1%– Spontaneous remission is rare

ITP

Chronic Form– Hospitalization common because of a complex

differential diagnosis– Multiple treatments– Platelet transfusions are used only for life

threatening bleeding– Life threatening bleeding is treated with IV

Immune globulin (1g/kg)

TTPHUS

Exist on a continuum and are likely the same disease

Diagnosed by a common pentad– Microangiopathic Hemolytic Anemia: Schistocytes

membranes are sheared passing through microthrombi– Thrombocytopenia: More sever in TTP– Fever– Renal Abnormalities: More prominent in HUS: include Renal

insufficiency, azotemia, proteinuria, hematuria, and renal failure

– Neurologic Abnormalities: hallmark of TTP 1/3 of HUS: Sx of HA, confusion, CN palsies, seizure,coma

TTPHUS

Labs– PT, PTT, and fibrinogen are within reference

range– Helmet Cells (Shistocytes) are common

TTPHUS

HUS– Most common in infants and children 6mo - 4

years– Often associated with a prodromal diarrhea– Strongest association to E. coli O157:H7 but also

associated with SSYC as well as multiple virus– Prognosis

Mortality 5-15% Younger patients do better

TTPHUS

HUS– Treatment

Mostly supportive Plasma exchange reserved for sever cases Treat hyperkalemia Avoid antibiotics with Ecoli

– May actually increase verotoxin production.– May be helpful with cases of Shigella dysenteriae

TTPHUS

TTP– More common in adults– Untreated mortality rate of 80% 1 to 3 months

after diagnosis– Aggressive plasma exchange has dropped the

mortality to 17%– Splenectomy, immune globulin, vincristine all play

a role in therapy

TTPHUS

AVOID PLATELET TRANSFUSION– May lead to additional microthrombi in circulation– Transfuse only with life threatening bleeding

Dilutional Thrombocytopenia

PRBC are platelet poor Monitor platelet count with every 10 u PRBC (for each 8-10 units of PRBC, 2 units of FFP

& 5 units of platelet concentrate are given) Transfuse when count below 50,000 Get them upstairs before you transfuse 10

units PRBC

Bleeding Clinical Correlation - PLT Numbers

PLT CountSpontaneous BleedPost Trauma Bleed

>50K/lNoRare

30 – 50K/lRareOccasional

10 – 30K/lOccasionalAlways

10K/lFrequentAlways

BT prolongation proportional to PLT count IF no complicating factors.

Significant Lab Data in Defects of Primary Hemostasis

TestVascular DisorderThrombocytopeniaPLT Dysfunction

PLT CountNDN

PTNNN

APTTNNN

BTN or ABNABNN or ABN

Hereditary Platelet Function DefectsHereditary Platelet Function Defects

Petechiaetypical of platelet abnormality

Do not blanch with pressure Not palpable

Bernard-Soulier Syndrome

First described in 1948 by Jean Bernard and Jean-Pierre Soulier; French hematologists

Bernard J, Soulier JP: Sur une nouvelle variete de dystrophie thrombocytaire hemarroagipare congenitale. Sem Hop Paris 24:3217, 1948

AR; characterized by moderate to severe thrombocytopenia, giant platelets, and perfuse/spontaneous bleeding

Basis for the disease is deficiency or dysfunction of the GP Ib-V-IX complex

Bernard-Soulier Syndrome

Decreased GP Ib-V-IX leads to decreased platelet Decreased GP Ib-V-IX leads to decreased platelet adhesion to the subendothelium via decreased binding of adhesion to the subendothelium via decreased binding of vWFvWF

Approximately 20,000 copies of GP Ib-V-IX per plateletApproximately 20,000 copies of GP Ib-V-IX per platelet GP 1b: heterodimer with an alpha and beta subunitGP 1b: heterodimer with an alpha and beta subunit The gene for GP Ib alpha is located on chromosome 17; The gene for GP Ib alpha is located on chromosome 17;

GP Ib beta: chromosome 22; GPIX and V: chromosome 3GP Ib beta: chromosome 22; GPIX and V: chromosome 3 Most mutations are missense or frameshifts resulting in Most mutations are missense or frameshifts resulting in

premature stop codonspremature stop codons Most mutations involve GP Ib expression (rare GP IX Most mutations involve GP Ib expression (rare GP IX

mutations have been described; no mutations in GP V)mutations have been described; no mutations in GP V)

Diagnosis

Prolonged bleeding time, thrombocytopenia Prolonged bleeding time, thrombocytopenia (plt>20 K), peripheral smear shows large (plt>20 K), peripheral smear shows large platelets (mean diameter >3.5 microns)platelets (mean diameter >3.5 microns)

Diagnosis

Platelet aggregation studies show normal aggregation in response to all agonists except Ristocetin (opposite pattern than thrombasthenia)

Flow cytometry: decreased expression of mAbs to CD 42b (GPIb), CD42a(GPIX), CD42d(GPV)

Platelet Aggregometer

Light focused on sample cuvette contained PRP

PRP stirred and recorder identified baseline – 0% transmittance

Agonist added Transmitted light changes

proportionally in response to degree PLT shape changes

Change in light transmission continuously monitored and recorded

As PLT aggregates form, recorder moves towards 100% transmittance

Abnormalities– Diminished or absent shape

change– Diminished aggregation

Graphic accessed URL http://evolvels.elsevier.com/section/default.asp?id=1138_ccalvo7_0001, 2008.

Platelet-rich plasma in an optical aggregometer. Platelet count is approximately 200 × 109/L, and platelets are maintained in suspension by a magnetic stir bar turning at 1000 rpm. (Courtesy of Kathy Jacobs, Chronolog, Inc., Havertown, Penn.)

Differentiation between vWD & BSD

Measuring the platelet aggregation response to ristocetin following the addition of PPP.

A normal aggregation response suggests the plasma defect, which is typical of vWD.

The persistence of defective response suggests the presence of a platelet defect which is typical of BSD.

Glanzmann’s ThrombastheniaGlanzmann’s Thrombasthenia

Eduard Glanzmann (1887-1959), Swiss Eduard Glanzmann (1887-1959), Swiss pediatricianpediatrician

Reported a case of a bleeding disorder starting Reported a case of a bleeding disorder starting immediately after birthimmediately after birth

W. E. Glanzmann:W. E. Glanzmann:Hereditäre hämorrhägische Hereditäre hämorrhägische Thrombasthenie. Ein Beitrag zur Pathologie Thrombasthenie. Ein Beitrag zur Pathologie der Blutplättchen.der Blutplättchen.Jahrbuch für Kinderheilkunde, 1918; 88: 1-Jahrbuch für Kinderheilkunde, 1918; 88: 1-42, 113-14142, 113-141. .

Glanzmann’sGlanzmann’s

IIbIIIa most abundant platelet surface receptor IIbIIIa most abundant platelet surface receptor (80,000 per platelet)(80,000 per platelet)

IIbIIIa complex is a Ca++ dependent heterodimerIIbIIIa complex is a Ca++ dependent heterodimer Genes for both subunits are found on Genes for both subunits are found on

Chromosome 17Chromosome 17 Disease is caused by mutations (substitution, Disease is caused by mutations (substitution,

insertion, deletion, splicing abnormalities) in insertion, deletion, splicing abnormalities) in genes encoding for IIb or IIIa resulting in genes encoding for IIb or IIIa resulting in qualitative or quantitative abnormalities of the qualitative or quantitative abnormalities of the proteinsproteins

Glanzmann’sGlanzmann’s

Fundamental defect of thrombasthenic Fundamental defect of thrombasthenic patients is the inability of the platelets to patients is the inability of the platelets to aggregateaggregate

Other problems: platelets do not spread Other problems: platelets do not spread normally on the subendothelial matrix (due to normally on the subendothelial matrix (due to lack of IIbIIIa – vWF/fibronectin interaction)lack of IIbIIIa – vWF/fibronectin interaction)

Also, alpha granule fibrinogen is decreased Also, alpha granule fibrinogen is decreased to absentto absent

Glanzmann’sGlanzmann’s

AR inheritance Patients present with wide spectrum of disease Like thrombocytopenic bleeding: skin, mucous

membrane (petichiae, echymoses), recurrent epistaxis, GI hemorrhage, menorrhagia, and immediate bleeding after trauma/surgery

ICH, joint, muscle bleeding uncommon

Glanzmann’s patients are stratified into three groups based on complex expression:– Type I less than 5 percent GPIIbIIIa, absent alpha

granule fibrinogen

Usually as a result of IIb gene mutation– Type II >20 percent, fibrinogen present– Type III >50 percent; “variant” thrombasthenia;

qualitative disorder

Diagnosis

Platelet count and morphology are normal Bleeding time prolonged The hallmark of the disease is severely

reduced or absent platelet aggregation in response to multiple agonists ie ADP, thrombin, or collagen (except Ristocetin)

Flow cytometry: decreased mAb expression of CD41 (GPIIb) and CD61 (GPIIIa)

Platelet Aggregation Studies

Platelet-rich plasma (PRP) is prepared from citrated whole blood by centrifugation

Inactive platelets impart a characteristic turbidity to PRP

When platelets aggregate after injection of an agonist, the turbidity falls, and light transmission through the sample increases proportionally

The change in light transmission can be recorded on an aggregometer

Agonists

Different concentrations of each agonist are used

ADP: biphasic pattern: First wave: low concentration, reversible Second wave: high concentration, irreversible

Other agonists

Epinephrine: triphasic (resting platelets, primary aggregation, secondary aggregation)

Other agonists

Collagen, arachidonic acid, Calcium ionophore, PAF are potent agonists and induce a single wave of irreversible aggregation

Ristocetin (antibiotic): aggregation can be reproduced with metabolically inert, formalin-fixed platelets

Defective risto-induced aggregation is characteristic of Bernard-Soulier

Problems with platelet aggregation Problems with platelet aggregation studiesstudies

Numerous variables affect aggregation:Anticoagulant (sodium citrate best)Plt count in PRPPlt size distributionTime of dayTemporal relation to meals and physical

activity

Storage Pool Defects

Classified by type of granular deficiency or secretion defect.

Dense body deficiency, alpha granule deficiency (gray platelet syndrome), mixed deficiency, Factor V Quebec

Defects in secondary aggregationDeficiency of contents of one of granulesInheritance is variable (heterogeneous group)Bleeding is usually mild to moderate but can

be exacerbated by aspirinClinical: easy bruising, menorrhagia, and

excessive postpartum or postoperative bleeding

Dense body deficiency

decreased dense bodies (ADP, ATP, calcium, pyrophosphate, 5HT)

Normal platelet contains 3-6, 300 micron dense bodies

Described in inherited disorders ie Hermansky-Pudlak syndrome, Wiskott-Aldrich syndrome, Chediak-Higashi syndrome, and Thrombocytopenia with absent radius (TAR) syndrome

Wiskott-Aldrich

X-linked, genetic defect in WASp (protein responsible for actin cytoskeleton formation in hematopoetic cells)

characterized by thrombocytopenia (with platelet storage pool defect), eczema, and recurrent infections

Hermansky-Pudlak

Described in 1959 by Hermansky and Pudlak AR, tyrosinase-positive oculocutaneous albinism,

ceroid-like deposition in lysosomes of the RES and marrow

Highest prevalence in Puerto Rico May be associated with pulmonary fibrosis, and

recurrent infections quantitative deficiency of dense granules leading

to mild-moderate bleeding diathesis

Chediak-Higashi

described by Beguez Cesar in 1943, Steinbrinck in 1948, Chédiak in 1952, and Higashi in 1954

AR; abnormal microtubule formation and giant lysozomal granules are present in phagocytes and melanocytes

No degranulation/chemotaxis = recurrent bacterial infections

Partial oculocutaneous albinism Dense-body granules decreased/absent

Thrombocytopenia with absent radius (TAR)

First described in 1951 AR, characterized by absent radii,

thrombocytopenia (with storage pool defect), and other abnormalities of the skeletal, GI, cardiovascular system

Etiology unclear Hemorrhage is the major cause of mortality PX is good if survive the two years

Typical Lab Findings– Usually normal platelet

count– Morphology is variable– Platelet aggregation

shows primary wave but absence of secondary wave when stimulated with ADP, epinephrine, arrachidonic acid

– Platelet aggregation with thrombin is usually normal (overrides need for granule release)

– Ristocetin agglutination is normal

Diagnosis – Measure the whole platelet

ATP/ADP ratioNormal: 2.5:1ADP storage pool deficiency

increased >3:1– Often associated with disorders

affecting granules in other cellsChediak-Higashi SyndromeHermansky-Pudlak SyndromeWiskott-Aldrich Syndrome

– Platelets are small with decreased number of both alpha and dense granules

Diagnosis

Platelet aggregation studies may show diminished response to low concentration collagen

ADP and epinephrine show diminished second wave response

Ristocetin shows normal aggregation EM: lack of dense bodies Increased ATP:ADP ratio within platelets

Alpha granule deficiency

Alpha storage pool deficiency, Gray Platelet Syndrome

First described by Raccuglia in 1971 Normal platelets contain approximately 50

granules (PF4, beta-thromboglobulin, PDGF, fibrinogen, vWF, Factor V, fibronectin)

Patients lack granules, present with lifelong, mild to moderate mucocutaneous bleeding

Diagnosis

Prolonged bleeding time, mild thrombocytopenia

A granular, large “gray” platelets on peripheral smear

Aggregation studies: decreased to absent response to collagen

Summary

Morphology and role of the platelet in primary hemostasis

Adhesion: GP1b-V-IX; Bernard-Soulier; aggregates with everything but Ristocetin

Activation (Secretion): dense body deficiency (associated syndromes), alpha granule deficiency

Aggregation: GPIIb-IIIa; Glanzmann’s; no aggregation except for Ristocetin

Differential diagnosisTable. The clinical distinction between disorders of vessels and platelets and disorders of blood coagulation

Fingdings Disorders of platelet or vessels

Disorders of coagulation

Petechiae Characteristic Rare

Deep dissecting hematomas

Rare Characteristic

Superficial ecchymoses Characteristic; usually small and multiple

Common; uaually large and solitary

Hemarthrosis Rare Characteristic

Delayed bleeding Rare Common

Bleeding from superficial cuts and scratches

Persistent; often profuse

Minimal

Sex of patient Relatively more common in females

80-90% of hereditary forms occur only in males

Positive family history Rare Common

Clinical Cases

Nail bed - Hematoma

•Red

•Blue/Gr

•Brown

Contusion - Hematoma

Laceration - Trauma

Petechiae & Echymoses -Plt

Petechiae & Echymoses -Plt

Bleeding-Coagulation disorder

•Deep bleeding

•Haematoma

•Joint bleeds

•Haemophilia

Jaundice

Leptospirosis - Weil’s disease:

Sub Conjuctival HaemorrhageLow PLT

Dengue – Hemorrhagic fever Plt

Bleeding disorders

Vascular abnormalities

Platelet disordersClotting factorabnormalities

DIC

Hereditary Type

The genetic defect can either be the failure of synthesis of one of the proteins or the production of a malfunctioning or abnormal molecule.

Quantitative vs Qualitative But in both of these genetic defects they will

result in slowing down and ineffective production of fibrin.

LAB Screening Tests

Lab screening tests are based on the length of time that it takes a clot to form in plasma.

So screening tests does not differentiate between qualitative or quantitative defects!

CRM + Vs CRM-

CRM is the abbreviation of Cross-Reacting Material Any protein has a functional activity and an immunologic

characteristics. Abnormal protein is functionally ineffective, but is

recognized immunologically.Is called CRM +

No protein (deficient) has no function and also will not be recognized immunologically.

Is called CRM -

Types of Bleeding Disorders

Hemophilia A (factor VIII deficiency)

Hemophilia B (factor IX deficiency)

von Willebrand Disease (vWD)

Other

Coagulation Platelet

Petechiae, Purpura Hematoma, Joint bl.

What is Hemophilia?

Hemophilia is an inherited bleeding disorder in which there is a deficiency or lack of factor VIII (hemophilia A) or factor IX (hemophilia B)

Hemophilia A and BHemophilia A Hemophilia B

Coagulation factor deficiency Factor VIII Factor IX

Inheritance X-linked X-linkedrecessive recessive

Incidence 1/10,000 males 1/50,000 males

Severity Related to factor level<1% - Severe - spontaneous bleeding

1-5% - Moderate - bleeding with mild injury 5-25% - Mild - bleeding with surgery or trauma

Complications Soft tissue bleeding

Inheritance of Hemophilia

Hemophilia A and B are X-linked recessive disorders

Hemophilia is typically expressed in males and carried by females

Severity level is consistent between family members

~30 % of cases of hemophilia are new mutations

Genetics of Hemophilia A

The gene F8 is located in the X chromosome, at Xq28, near telomeric region.

It consists of 26 exons, and 25 introns. The F8 gene spans 186 Kb. Mature RNA is 8.8 Kb. The F8 protein is 2351 amino acid. The leader sequence is 19 a.a. So the real protein= 2351-19= 2332 aa.

Genetics of Hemophilia A

Half of hemophilia A patients have no detectable factor VIII;

about 5% have normal levels of dysfunctional factor VIII as protein and are termed CRM+

whereas the rest (45%) have plasma factor VIII Ag protein reduced to an extent roughly comparable to the level of factor VIII:C activity and are designated CRM-.

Detection of Hemophilia

Family history Symptoms

– Bruising– Bleeding with circumcision– Muscle, joint, or soft tissue bleeding

Hemostatic challenges– Surgery– Dental work– Trauma, accidents

Laboratory testing

Screening Tests in Secondary Hemostasis Defects

PT is prolonged or (test extrinsic pathway) APTT is prolonged or (test intrinsic pathway) Both are prolonged. Platelets are normal in count and function. TT (thrombin time): prolonged in disorders of

fibrinogen. If any test is abnormal of these screening tests,

additional testing may resolve the disorder>>>>

Additional Testing

Specific Factor Assays. Fibrinogen Level D-Dimer FDP’s Antithrombin Level The list continues to expand………….

Degrees of Severity of Hemophilia

Normal factor VIII or IX level = 50-150%

Mild hemophilia– factor VIII or IX level = 6-50%

Moderate hemophilia– factor VIII or IX level = 1-5%

Severe hemophilia– factor VIII or IX level = >1%

Hemophilia Prevalence

Hemophilia A; 1 in 5000 population – coagulation factor VIII deficiency

Hemophilia B; 1 in 30000 population – coagulation factor IX deficiency

Hemophilia A is six-fold more prevalent than hemophilia B.

Types of Bleeds

Joint bleeding - hemarthrosis

Muscle hemorrhage

Soft tissue

Life threatening-bleeding

Other

Hemarthrosis

Joint or Muscle Bleeding

Symptoms– Tingling or bubbling sensation– Stiffness– Warmth– Pain– Unusual limb position

Life-Threatening Bleeding

Head / Intracranial– Nausea, vomiting, headache, drowsiness, confusion, visual

changes, loss of consciousness

Neck and Throat– Pain, swelling, difficulty breathing/swallowing

Abdominal / GI– Pain, tenderness, swelling, blood in the stools

Iliopsoas Muscle– Back pain, abdominal pain, thigh tingling/numbness, decreased

hip range of motion

Other Bleeding Episodes

Mouth bleeding

Nose bleeding

Scrapes and/or minor cuts

Menorrhagia

Complications of Bleeding

Flexion contractures

Joint arthritis / arthropathy

Chronic pain

Muscle atrophy

Compartment syndrome

Neurologic impairment

Hemophilia “General Consideration”

There is a strong correlation between residual clotting factor level and severity of bleeding symptoms.

Spontaneous bleeding is only seen in severe disease.

Affected males with severe disease are generally diagnosed by the age of one year.

Even where there is no prior family history of hemophilia, sporadic cases caused by new mutations, which are responsible for 1/3 of cases.

In males with mild hemophilia, it is not unusual for the disorder to not be diagnosed until middle age, possibly following prolonged bleeding at surgery.

Treatment of Hemophilia

Replacement of missing clotting protein– On demand– Prophylaxis

DDAVP / Stimate Antifibrinolytic Agents

– Amicar Supportive measures

– Icing– Immobilization– Rest

Factor VIII Concentrate

Intravenous infusion– IV push– Continuous infusion

Dose varies depending on type of bleeding– Ranges from 20-50+ units/kg. body weight

Half-life 8-12 hours Each unit infused raises serum factor VIII

level by 2 %

Factor IX Concentrate

Intravenous infusion– IV push– Continuous infusion

Dose varies depending on type of bleeding – Ranges from 20-100+ units/kg. body weight

Half-life 12-24 hours Each unit infused raises serum factor IX level

by 1%

History of Clotting Factor Concentrates

Prior to 1950: whole blood

1952: Hemophilia A distinguished from B

1950-1960: FFP and Cryoprecipitate

Early 1970s: Commercial plasma-derived factor concentrates

Mid-late 1970’s: Home infusion practices

1981: First AIDS death in the Hemophilia community

History of Clotting Factor Concentrates (cont’d)

Mid-1983: Factor concentrates heat treated for hepatitis

1985: All products heat treated for viral inactivation

1987: Monoclonal factor concentrates

1992: Recombinant factor VIII

1994: Recombinant factor IX-albumin free

2001: 2nd generation recombinant factor VIII

Infusions of Factor Concentrates

Verify product with physician order. Dose may be +/- 10% ordered. Do not waste factor even if the dose is not exactly

what is ordered. Reconstitute factor per package insert. Infusion rate per package insert or pharmacy

instructions. Document lot number, expiration date, time of

infusion, and exact dose given in units.

Prophylaxis

Scheduled infusions of factor concentrates to prevent most bleeding

Frequency: 2 to 3 times weekly to keep trough factor VIII or IX levels at 2-3%

Types– primary prophylaxis– secondary prophylaxis

Use of IVAD necessary in some patients

DDAVP (Desmopressin acetate)

Synthetic vasopressinMethod of action -

– release of stores from endothelial cells raising factor VIII and vWD serum levels

Administration -– Intravenous– Subcutaneously– Nasally (Stimate)

Side effects

Stimate

How supplied– 1.5 mg./ ml (NOT to be confused with DDAVP nasal spray

for nocturnal enuresis) – 2.5 ml bottle - delivers 25 doses of 150 mcg.

Dosing– Every 24-48 hours prn– >50 kg. body weight - 1 spray (150 mcg.)– >50 kg. body weight - 2 sprays (300 mcg.)

Amicar(epsilon amino caproic acid)

AntifibrinolyticUses

– Mucocutaneous bleeding

Dosing: 50 - 100 mg./kg. q. 6 hoursSide effectsContraindications

– Hematuria

Complications of Treatment

Inhibitors/Antibody developmentHepatitis AHepatitis BHepatitis CHIV

Inhibitors

Definition – IgG antibody to infused factor VIII or IX

concentrates, which occurs after exposure to the extraneous VIII or IX protein.

Prevalence– 20-30% of patients with severe hemophilia A– 1-4% of patients with severe hemophilia B

Hepatitis

Hepatitis A- small risk of transmission– Vaccination recommended

Hepatitis B - no transmissions since 1985– Vaccination recommended

Hepatitis C - no transmissions since 1990– ~90% of patients receiving factor concentrates prior to 1985

are HCV antibody positive

Human Immunodeficiency Virus

No transmissions of HIV through factor concentrates since 1985 due to viral inactivation procedures

HIV seropositive rate -– 69.6% of patients with severe hemophilia A receiving

factor concentrates prior to 1985

– 48.6% of patients with severe hemophilia B receiving factor concentrates prior to 1985

Nursing Considerations

Factor replacement to be given on time Laboratory monitoring Increase metabolic states will increase factor

requirements Factor coverage for invasive procedures Document - infusions, response to treatment Avoid NSAIDS Utilize Hemophilia Center staff for questions /

problems

Psychosocial Issues

GuiltChallenge of hospitalizationsControl issuesFinancial / insurance challengesFeeling different / unable to do certain

activities Counseling needs

Hemophilia Treatment Center Team Members

Patient / Family

Hematologist

Nurse

Social Worker

Physical Therapist

Orthopedist

Primary Care

Infectious Disease

Genetics

Pharmacy

Dental

Hepatology

Role of Hemophilia Treatment Centers

State-of-the-art medical treatment for persons with hemophilia through the life span

Education Research Outreach Model of comprehensive care for chronic

disease

von Willebrand’s Disease

Outline

vWF– Structure– Location– Function

vWD– History– Clinical manifestations – Categories– Diagnosis– Treatment

vWD

Family of bleeding disorders Caused by a deficiency or an abnormality of

von Willebrand Factor

vWF

VWF gene : short arm of chromosome 12– VWF gene is expressed in endothelial cells and

megakaryocytes vWF is produced as a propeptide which is extensively modified to

produce mature vWF– Two vWF monomers bind through disulfide bonds to form

dimers– Multiple dimers combine to form vWF multimers

vWF Production

Vascular endothelial cells Megakaryocytes Most vWF is secreted Some vWF is stored

– Weibel-Palade bodies in endothelial cells

– Alpha granules of platelets

Constitutive and stimulus-induced pathways

Release stimuli (EC)– Thrombin– Histamine– Fibrin– C5b-9 (complement

membrane attack complex)

Release stimuli (platelets)– Thrombin– ADP– Collagen

vWF Function

Adhesion– Mediates the adhesion

of platelets to sites of vascular injury (subendothelium)

Links exposed collagen to platelets

– Mediates platelet to platelet interaction

Binds GPIb and GPIIb-IIIa on activated platelets

Stabilizes the hemostatic plug against shear forces

vW Factor Functions in Hemostasis

Carrier protein for Factor VIII (FVIII)– Protects FVIII from proteolytic degradation– Localizes FVIII to the site of vascular injury– Hemophilia A: absence of FVIII

vWD History

1931: Erik von Willebrand described novel bleeding disorder– Hereditary

pseudohemophilia– Prolonged BT and

normal platelet count– Mucosal bleeding – Both sexes affected

1950s: Prolonged BT associated with reduced FVIII

1970s: Discovery of vWF 1980s: vWF gene cloned

Frequency

Most frequent inherited bleeding disorder– Estimated that 1% of the population has vWD– Very wide range of clinical manifestations– Clinically significant vWD : 125 persons per million

population– Severe disease is found in approximately 0.5-5

persons per million population Autosomal inheritance pattern

– Males and females are affected equally

vWD Classification

Disease is due to either a quantitative deficiency of vWF or to functional deficiencies of vWF– Due to vWF role as carrier protein for FVIII,

inadequate amount of vWF or improperly functioning vWF can lead to a resultant decrease in the available amount of FVIII

vWD Classification

3 major subclasses– Type I: Partial quantitative deficiency of vWF

Mild-moderate disease 70%

– Type II: Qualitative deficiency of vWF Mild to moderate disease 25%

– Type III: Total or near total deficiency of vWF Severe disease 5%

Additional subclass– Acquired vWD

Clinical Manifestations

Most with the disease have few or no symptoms

For most with symptoms, it is a mild manageable bleeding disorder with clinically severe hemorrhage only with trauma or surgery

Types II and III: Bleeding episodes may be severe and potentially life threatening

Disease may be more pronounced in females because of menorrhagia

Bleeding often exacerbated by the ingestion of aspirin

Severity of symptoms tends to decrease with age due to increasing amounts of vWF

Clinical Manifestations

Epistaxis 60% Easy bruising / hematomas 40% Menorrhagia 35% Gingival bleeding 35% GI bleeding 10% Dental extractions 50% Trauma/wounds 35% Post-partum 25% Post-operative 20%

vWD Type I

Mild to moderate disease Mild quantitative deficiency of vWF

– vWF is functionally normal Usually autosomal dominant

– Penetrance may vary dramatically in a single family

vWD Type 2

Usually autosomal dominant

Type 2A – Lack high and

intermediate molecular weight multimers

Type 2B– Multimers bind platelets

excessively Increased clearance

of platelets from the circulation

– Lack high molecular weight multimers

Type 2C– Recessive – High molecular weight vWF

multimers is reduced – Individual multimers are

qualitatively abnormal Type 2M

– Decreased vWF activity– vWF antigen, FVIII, and

multimer analysis are found to be within reference range

Type 2N– Markedly decreased affinity

of vWF for FVIII Results in FVIII levels

reduced to usually around 5% of the reference range.

vWD Type III

Recessive disorder vWF protein is virtually undetectable

– Absence of vWF causes a secondary deficiency of FVIII and a subsequent severe combined defect in blood clotting and platelet adhesion

Acquired vWD

First described in 1970's fewer than 300 cases reported Usually encountered in adults with no personal or family

bleeding history Laboratory work-up most consistent with Type II vWD Mechanisms

– Autoantibodies to vWF– Absorption of HMW vWF multimers to tumors and activated

cells– Increased proteolysis of vWF– Defective synthesis and release of vWF from cellular

compartments Myeloproliferative disorders, lymphoproliferative disorders,

monoclonal gammopathies, CVD, and following certain infections

vWD Screening

PT aPTT (Bleeding time)

vWD: aPTT and PT

aPTT– Mildly prolonged in approximately 50% of patients

with vWD Normal PTT does not rule out vWD

– Prolongation is secondary to low levels of FVIII PT

– Usually within reference ranges Prolongations of both the PT and the aPTT signal a

problem with acquisition of a proper specimen or a disorder other than or in addition to vWD

vWD and Bleeding Time

Historically, bleeding time is a test used to help diagnose vWD– Lacks sensitivity and specificity– Subject to wide variation– Not currently recommended for making the

diagnosis of vWD

vWD Diagnostic Difficulties

vWF levels vary greatly– Physiologic stress– Estrogens– Vasopressin– Growth hormone– Adrenergic stimuli

vWF levels may be normal intermittently in patients with vWD– Measurements should be repeated to confirm abnormal

results– Repeating tests at intervals of more than 2 weeks is

advisable to confirm or definitively exclude the diagnosis, optimally at a time remote from hemorrhagic events, pregnancy, infections, and strenuous exercise

vWF levels vary with blood type

vWD Diagnosis

Ristocetin– Good for evaluating vWF function, – Results are difficult to standardize – Method

Induces vWF binding to GP1b on platelets Ristocetin co-factor activity: measures agglutination of

metabolically inactive platelets RIPA: metabolically active platelets Aggregometer is used to measure the rate of aggregation

vWF Antigen– Quantitative immunoassay or an ELISA using an antibody to

vWF Discrepancy between the vWF:Ag value and RCoF activity

suggests a qualitative defect – Should be further investigated by characterization of the vWF

multimeric distribution

Additional Assays

Multimer analysis PFA-100 closure time

– Screens platelet function in whole blood

– Prolonged in vWD, except Type 2N

FVIII activity assay

vWD Treatment

DDAVP Cryoprecipitate FVIII concentrate

vWD and DDAVP

Treatment of choice for vWD type I– Synthetic analogue of the antidiuretic hormone

vasopressin– Maximal rise of vWF and FVIII is observed in 30-60

minutes– Typical maximal rise is 2- to 4-fold for vWF and 3- to 6-

fold for FVIII– Hemostatic levels of both factors are usually maintained

for at least 6 hours– Effective for some forms of Type 2 vWD

May cause thrombocytopenia in Type 2b– Ineffective for vWD Type 3

Factor VIII Concentrates

Alphanate and Humate P Concentrates are purified to reduce the risk of

blood-borne disease Contain a near-normal complement of high

molecular weight vWF multimers

vWD Treatment

Platelet transfusions– May be helpful with vWD refractory to other therapies

Cryoprecipitate– Fraction of human plasma– Contains both FVIII and vWF– Medical and Scientific Advisory council of the National

Hemophilia Foundation no longer recommends this treatment method due to its associated risks of infection

FFP– An additional drawback of fresh frozen plasma is the large

infusion volume required

Disseminated Intravascular Coagulation

DIC

An acquired syndrome characterized by systemic intravascular coagulation

Coagulation is always the initial event.

Most morbidity and mortality depends on extent of intravascular thrombosis

Multiple causes

6

ThrombosisThrombosis

FibrinFibrin

Red Blood CellRed Blood Cell

PlateletPlatelet

WWW. Coumadin.com

DIC

An acquired syndrome characterized by systemic intravascular coagulation

Coagulation is always the initial event

SYSTEMIC ACTIVATION OF COAGULATION

Intravascular deposition of

fibrin

Depletion of platelets and coagulation

factors

Thrombosis of small and

midsize vesselsBleeding

Organ failure DEATHDEATH

Pathophysiology of DIC

Activation of Blood Coagulation Suppression of Physiologic Anticoagulant

Pathways Impaired Fibrinolysis Cytokines

Pathophysiology of DIC

Activation of Blood Coagulation– Tissue factor/factor VIIa mediated thrombin generation

via the extrinsic pathway complex activates factor IX and X

– TF endothelial cells monocytes Extravascular:

– lung– kidney– epithelial cells

Pathophysiology of DIC

Suppression of Physiologic Anticoagulant Pathways– reduced antithrombin III levels – reduced activity of the protein C-protein S system– Insufficient regulation of tissue factor activity by

tissue factor pathway inhibitor (TFPI)inhibits TF/FVIIa/Fxa complex activity

Pathophysiology of DIC

Impaired Fibrinolysis– relatively suppressed at time of maximal activation

of coagulation due to increased plasminogen activator inhibitor type 1

Pathophysiology of DIC - Cytokines

Cytokines– IL-6, and IL-1 mediates coagulation activation in DIC– TNF-

mediates dysregulation of physiologic anticoagulant pathways and fibrinolysis

modulates IL-6 activity– IL-10 may modulate the activation of coagulation

CoagulationInflamation

Diagnosis of DIC

Presence of disease associated with DIC Appropriate clinical setting

– Clinical evidence of thrombosis, hemorrhage or both.

Laboratory studies– no single test is accurate– serial test are more helpful than single test

Conditions Associated With DIC

Malignancy– Leukemia– Metastatic disease

Cardiovascular– Post cardiac arrest– Acute MI– Prosthetic devices

Hypothermia/Hyperthermia

Pulmonary– ARDS/RDS– Pulmonary

embolism

Severe acidosis Severe anoxia Collagen vascular

disease Anaphylaxis

Conditions Associated With DIC

Infectious/Septicemia– Bacterial

Gm - / Gm +

– Viral CMV Varicella Hepatitis

– Fungal

Intravascular hemolysis Acute Liver Disease

Tissue Injury– trauma– extensive surgery– tissue necrosis– head trauma

Obstetric– Amniotic fluid emboli– Placental abruption– Eclampsia– Missed abortion

Clinical Manifestations of DIC

ORGAN ISCHEMIC HEMOR.Skin Pur. Fulminans

GangreneAcral cyanosis

PetechiaeEchymosisOozing

CNS Delirium/ComaInfarcts

Intracranialbleeding

Renal Oliguria/AzotemiaCortical Necrosis

Hematuria

Cardiovascular MyocardialDysfxn

Pulmonary Dyspnea/HypoxiaInfarct

Hemorrhagiclung

GIEndocrine

Ulcers, InfarctsAdrenal infarcts

Massivehemorrhage.

Ischemic Findingsare earliest!

Bleeding is the most obvious

clinical finding

Clinical Manifestations of DIC

Microscopic findings in DIC

Fragments Schistocytes Paucity of platelets

Laboratory Tests Used in DIC

D-dimer* Antithrombin III* F. 1+2* Fibrinopeptide A* Platelet factor 4* Fibrin Degradation

Prod Platelet count Protamine test

Thrombin time Fibrinogen Prothrombin time Activated PTT Protamine test Reptilase time Coagulation factor levels

*Most reliable test

Laboratory diagnosis

Thrombocytopenia– plat count >100,000 or rapidly declining

Prolonged clotting times (PT, APTT) Presence of Fibrin degradation products or positive

D-dimer Low levels of coagulation inhibitors

– AT III, protein C

Low levels of coagulation factors– Factors V,VIII,X,XIII

Fibrinogen levels not useful diagnostically

Differential Diagnosis

Severe liver failure Vitamin K deficiency Liver disease Thrombotic thrombocytopenic purpura Congenital abnormalities of fibrinogen HELLP syndrome

Treatment of DIC

Stop the triggering process .– The only proven treatment!

Supportive therapy No specific treatments

– Plasma and platelet substitution therapy– Anticoagulants– Physiologic coagulation inhibitors

Plasma therapy

Indications– Active bleeding– Patient requiring invasive procedures– Patient at high risk for bleeding complications

Prophylactic therapy has no proven benefit. Cons: Fresh frozen plasma(FFP):

– provides clotting factors, fibrinogen, inhibitors, and platelets in balanced amounts.

– Usual dose is 10-15 ml/kg

Platelet therapy

Indications– Active bleeding– Patient requiring invasive procedures– Patient at high risk for bleeding complications

Platelets– approximate dose 1 unit/10kg

Blood

Replaced as needed to maintain adequate oxygen delivery.– Blood loss due to bleeding– RBC destruction (hemolysis)

Coagulation Inhibitor Therapy

Antithrombin III Protein C concentrate Tissue Factor Pathway Inhibitor (TFPI) Heparin

The major inhibitor of the coagulation cascade– Levels are decreased in DIC.– Anticoagulant and antiinflammatory properties

Therapeutic goal is to achieve supranormal levels of ATIII (>125-150%).

– Experimental data indicated a beneficial effect in preventing or attenuating DIC in septic shock

reduced DIC scores, DIC duration, and some improvement in organ function

– Clinical trials have shown laboratory evidence of attenuation of DIC and trends toward improved outcomes.

– A clear benefit has not been established in clinical trials.

Antithrombin III

Protein C Concentrates

Inhibits Factor Va, VIIa and PAI-1 in conjunction with thrombomodulin.

Protein S is a cofactor Therapeutic use in DIC is experimental and is based on

studies that show:– Patients with congenital deficiency are prone to thromboembolic

disease.– Protein C levels are low in DIC due to sepsis.– Levels correlate with outcome.– Clinical trials show significantly decreased morbidity and

mortality in DIC due to sepsis.

Tissue Factor Pathway Inhibitor

Tissue factor is expressed on endothelial cells and macrophages

TFPI complexes with TF, Factor VIIa,and Factor Xa to inhibit generation of thrombin from prothrombin

TF inhibition may also have antiinflammatory effects Clinical studies using recombinant TFPI are

promising.

Heparin

Use is very controversial. Data is mixed. May be indicated in patients with clinical

evidence of fibrin deposition or significant thrombosis.

Generally contraindicated in patients with significant bleeding and CNS insults.

Dosing and route of administration varies. Requires normal levels of ATIII.

Antifibrinolytic Therapy

Rarely indicated in DIC– Fibrinolysis is needed to clear thrombi from the micro

circulation.– Use can lead to fatal disseminated thrombosis.

May be indicated for life threatening bleeding under the following conditions:

– bleeding has not responded to other therapies and:– laboratory evidence of overwhelming fibrinolysis.– evidence that the intravascular coagulation has ceased.

Agents: tranexamic acid, EACA

Summary

DIC is a syndrome characterized systemic intravascular coagulation.

Coagulation is the initial event and the extent of intravascular thrombosis has the greatest impact on morbidity and mortality.

Important link between inflammation and coagulation. Morbidity and mortality remain high. The only proven treatment is reversal or control

of the underlying cause.