(F) Lesson 9: Vascular and Platelet Disorders Flashcards by Shen Gabriel

Vascular Disorders

Vascular disorders can be classified into either primary or secondary:

There is a disease association
There is no known disease associated

Secondary
Primary

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

Manifests with thin-walled vessels due to a lack of supporting tissues surrounding the vessels (e.g. smooth muscle deficiency, discontinued endothelial lining, etc.)
There is dilation of the vessels commonly seen in the lips and eyes
There is also the breakage of vessels in the nostrils

Hereditary Hemorrhagic Telangiectasia

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

Identify the Medical Terms:
1. Thin-walled vessels
2. Nosebleed

Telangiectasia
Epistaxis

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

What is the other name for Hereditary Hemorrhagic Telangiectasia?

Rendu-Osler-Weber Syndrome

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

When one is experiencing epistaxis (nosebleeding), there is a possible problem with hemostasis if:
1. The bleed requires ____ before it can be stopped
2. The duration is more than ____ minutes

Mechanical Pressure
10 minutes

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

TOF: Epistaxis (nosebleeding) can only be seen in issues with the vessels

False (it also manifests with platelet problems)

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

If there is a deficiency with this control protein, the complement activity cannot be fully controlled leading to increased release of anaphylatoxins

Increased anaphylatoxins induce increased vascular permeability because these initiate an inflammatory response leading to bleeding

C1 Inhibitor

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

This is a form of bleeding diathesis/disorder
A vascular tumor presents as a tuft of capillaries which causes pooling of the platelets
Since it attracts platelets, thrombocytopenia occurs

Hemangioma-Thrombocytopenia Syndrome

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

What is the other name for Hemangioma-Thrombocytopenia Syndrome?

Kasabach-Merritt Syndrome

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

Can be an autosomal dominant/recessive/X-linked trait
Manifests with hyper-extensible skin, hyper-mobile joints, joint laxity, fragile tissue, and bleeding tendencies

Ehlers-Danlos Syndrome

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

The problem lies with the abnormal formation of collagen leading to the inability to support the skin and blood vessels
A lack of collagen decreases the number of available surfaces the platelets can bind to
Patients have a tendency to bruise easily as well as experience prolonged bleeding

Ehlers-Danlos Syndrome

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

Patients present with excessively long extremities and digits (not proportional to the torso)
There is a problem with the connective tissue (e.g. collagen, elastic fibers, and other supporting membranes)
Weakened blood vessels can balloon and lead to an aneurysm especially in the aorta

Marfan Syndrome

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

A connective tissue problem which manifests with weakened and soft bones

Osteogenic Imperfecta

How well did you know this?

Not at all

Perfectly

Hereditary Vascular Disorders

There is a deficiency/defect with elastic fiber formation in the patient
It presents with striations in the skin and eyes

Pseudoxanthoma Elasticum

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

This presents with a skin rash and edema due to drugs, food, insect bites, and vaccinations
Manifests as arthralgia, nephritis, abdominal pain, and purpuric skin lesions
The body produces IgA immune complexes which stick to blood vessels to induce inflammation leading to its destruction

Henoch-Schonlein Purpura

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

What is the other name for Henoch-Schonlein Purpura?

Anaphylactoid/Allergic Purpura

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

There is a coating of the platelet membranes leading to platelet adhesion and clot formation on the platelet surface
Certain proteins can be deposited on the vessel walls which induce inflammatory responses (recruitment of phagocytes) that damage the vessels

Paraproteinemia and Amyloidosis

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

Familiarize yourself with the proteins and conditions involved in Paraproteinemia and Amyloidosis

Myeloma proteins
- IgA and IgG myeloma
- Waldenstrom’s macroglobulinemia

Amyloid fibrous proteins
- Aggregated fibrils
- Purpura, hemorrhage, and thrombosis
- Abnormal platelet function

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

Common in elderly men than women
There is a lack of collagen support for small vessels (increased capillary fragility) and a loss of subcutaneous fats and elastic fibers
Manifests with 1-10mm diameter dark blotches that do not blanch upon applying pressure

Senile Purpura

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

In Senile Pupura, what are the expected lab results of the patients’ sample?

Normal with no other chemical bleeding manifestations

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

There is decreased synthesis of collagen leading to weak capillary walls which presents with purpuric lesions
Manifests with bleeding gums, gingivitis, loss of teeth, pinpoint (petechial) hemorrhages on the hair follicles, fatigue, depression, increased susceptibility to infections, muscle weakness, joint bleeding, body aches, and many more

Scurvy (Vitamin C Deficiency)

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

Vitamin C is one of the vitamins that we (can/cannot) naturally synthesize in our bodies

Cannot (hence, it is an essential vitamin)

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

Refers to pinpoint hemorrhages on the hair follicle

Corkscrew Bleeding

How well did you know this?

Not at all

Perfectly

Acquired Vascular Disorders

There is medication-induced vasculitis but still with functionally adequate platelets
Antibodies may develop against the vessel wall after taking the medication (formation of immune complexes) leading to increased vascular permeability

Drug-induced Vascular Purpura

How well did you know this?

Not at all

Perfectly

# Acquired Vascular Disorders Familiarize yourself with the drugs involved in Drug-induced Vascular Purpura

1. Aspirin 2. Warfarin 3. Barbiturates 4. Diuretics 5. Digoxin 6. Methyldopa 7. Antibiotics 8. Sulfonamides 9. Iodides

# Vascular Disorders According to the list, what are the 2 purpuras of unknown origin?

1. Purpura Simplex 2. Psychogenic Purpura

# Platelet Disorders (Quantitative: Thrombocytosis) - Refers to the normal response of the body to produce more platelets due to blood loss and surgery (e.g. splenectomy) - IDA, inflammation and their diseases, stress, and exercise are common stimulants of this disorder

Reactive Thrombocytosis

# Platelet Disorders (Quantitative: Thrombocytosis) In Reactive Thrombocytosis: 1. TOF: When IDA normalizes, platelet count also returns back to normal 2. TOF: When we release APRs during inflammation, it tends to decrease platelets because it may reflect as an APR as well

1. True 2. False (increase)

# Platelet Disorders (Quantitative: Thrombocytosis) During blood loss, platelets will naturally decrease but due to this stimulant in the liver and bone marrow to release more, the platelet count will suddenly increase. What is this phenomenon called?

Rebound Thrombocytosis

# Platelet Disorders (Quantitative: Myeloproliferative Disorders) - The uncontrolled production of blood cells because of a genetic abnormality in an enzyme that stimulates the BM to produce cells - The hyper-viscosity of the blood due to the increased RBC count can clog the vessels leading to platelet activation, thrombosis, and bleeding

Polycythemia Vera

# Platelet Disorders (Quantitative: Myeloproliferative Disorders) In Polycythemia Vera, what enzyme carries a genetic abnormality?

Tyrosine Kinase

# Platelet Disorders (Quantitative: Myeloproliferative Disorders) This type of cancer is due to the overactivity of BM cells

Chronic Myelogenous Leukemia (CML)

# Platelet Disorders (Quantitative: Myeloproliferative Disorders) - Platelets and megakaryocytes are stimulated to release PDGF (alpha granules) which induces fibrous tissue formation (scar tissue replaces normal BM cells) - Commonly associated with tear-drop cells in the PBS and can also be a form of cancer

Myelofibrosis with Myeloid Metaplasia

# Platelet Disorders (Quantitative: Myeloproliferative Disorders) - A condition wherein the platelet count reaches over 1,000 x 10^9/L (max. of 400-450) - It may lead to thrombosis (increased TXA2) and hemorrhage (lack of EPI response and decreased synthesis of ADP within the platelet)

Essential or Primary Thrombocythemia

# Platelet Disorders (Quantitative: Myeloproliferative Disorders) 1. (Increased/Decreased) TXA2 activates the platelet aggregation process 2. Epinephrine and ADP are platelet aggregators, so a/an (increase/decrease) in these impairs the aggregation process

1. Increased 2. Decrease

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Congenital - A genetic disorder where WBCs contain Dohle-like bodies accompanied by giant platelets leading to a decreased response to activating/aggregating agents - There is a mutation in the MYH9 gene which encodes non-muscle myosin heavy chains

May-Hegglin Anomaly

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Congenital - There is a decrease in dense granule content resulting in decreased function - Megakaryocytes with abnormal ultrastructures increase in number

May-Hegglin Anomaly

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Congenital What gene is mutated in a May-Hegglin Anomaly?

MYH9 gene

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Congenital Is it a May-Hegglin Anomaly or Not? Dohle bodies are seen accompanied by normal-looking platelets caused by trauma, injury, or infection

Not a May-Hegglin Anomaly

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Congenital These are blue spindles shown on the PBS after staining the slide with Wright’s stain

Pseudo-Dohle Bodies

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Congenital - A genetic mutation or deletion of 200kbs in the RBM8A gene (1q21.1) - Presents with bony abnormalities, cardiac lesions, and leukemoid reactions (high immature WBC count)

Thrombocytopenia-Absent Radius (TAR) Syndrome

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Congenital 1. What gene is mutated or deleted in TAR syndrome? 2. What area of the chromosome can it be found on? 3. How many kbps are deleted?

1. RBM8A 2. 1q21.1 3. 200kbps

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Congenital - There is hypoplasia of the radial bones of the forearms with absent, short, or malformed ulnae - Platelet counts decrease by 10,000-30,000/µL in infancy

Thrombocytopenia-Absent Radius (TAR) Syndrome

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Neonatal - Presents with a platelet count of < 150,000/µL depending on the period of life - Is present 1-5% of the time at birth; 75% of cases are already present on or within 72 hours of life

Neonatal Thrombocytopenia

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Neonatal Familiarize yourself with the causes of Neonatal Thrombocytopenia once it is already present during the fetal stage

1. Congenital infections (TORCH and HIV) 2. Trisomy and triploidy (aneuploidy) 3. May be alloimmune or autoimmune 4. HDN, Wiskott-Aldrich Syndrome, and drugs (chlorothiazide diuretics and tolbutamide)

# Platelet Disorders (Quantitative: Thrombocytopenia) Impaired or Decreased Production: Acquired 1. ____ prevents folic acid absorption which is important for DNA synthesis leading to decreased platelet count 2. If you have ____ anemia due to lack of folate, there is an observed decrease in blood cell count

1. Ethanol 2. Megaloblastic anemia

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune - Refers to when antibodies produced due to viral infections/live attenuated vaccines also cross react with the platelets leading to their destruction - Can be acute or chronic

Immune Thrombocytopenic Purpura (ITP)

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune (Acute or Chronic) - Presents with bruising, petechiae, and mucosal bleeding (epistaxis) - Is commonly seen in children and may be self-limiting but remissions are possible in 80% of the cases

Acute

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune (Acute or Chronic) - Presents with mucocutaneous bleeding, menorrhagia for females, recurrent epistaxis, and easy bruising - Is commonly seen in later ages such as 20 to 40 years old

Chronic

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune Familiarize yourself with the platelet components targetted by the autoantibodies produced in Immune Thrombocytopenic Purpura (ITP)

- GP IIB and IIIA - GP IA and IIA - IgG antibodies

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune Familiarize yourself with the 4 mechanisms of Drug-Induced Thrombocytopenia

1. Hapten-induced 2. Drug-dependent 3. Drug-induced autoantibodies 4. Immune complexes

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Drug-Induced Thrombocytopenia Mechanism After intaking the drugs, the body metabolizes it which mixes with your plasma proteins turning into a complete antigen which can trigger an immune response

Hapten-Induced

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Drug-Induced Thrombocytopenia Mechanism - An antigen-antibody complex gets formed and the Fab portion of the quinine-dependent antibody will bind to GPIX of the platelet which appears like a new protein capable of triggering an immune response - Since the Fc region of the antibody is exposed, macrophages are able to attach to it

Drug-dependent

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Drug-Induced Thrombocytopenia Mechanism Antibodies are produced for both the drugs and the cells (e.g. gold salts, procainamide, etc.)

Drug-induced Autoantibodies

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Drug-Induced Thrombocytopenia Mechanism An example of this is Heparin-Induced Thrombocytopenia (HIT)

Immune Complexes

# Platelet Disorders (Quantitative: Thrombocytopenia) Heparin-Induced Thrombocytopenia (HIT) What is its other name?

“Heparin-Induced Thrombotic Thrombocytopenic Syndrome”

# Platelet Disorders (Quantitative: Thrombocytopenia) Heparin-Induced Thrombocytopenia (HIT) - Excessive amounts of heparin can lead to the binding of ____ which is responsible for neutralizing the heparin that is naturally present in our bodies to continue with clotting - This leads to the formation of new proteins/antigens which leads to the production of ____ antibodies

1. Platelet Factor 4 (PF4) 2. HIT antibodies

# Platelet Disorders (Quantitative: Thrombocytopenia) Heparin-Induced Thrombocytopenia (HIT) - The ____ regions of the HIT antibodies will bind to the platelets and induce clumping (thrombus formation) - ____ occurs due to the platelets being used up for the thrombus formation

1. Fc 2. Thrombocytopenia

# Platelet Disorders (Quantitative: Thrombocytopenia) Tests for Heparin-Induced Thrombocytopenia (HIT) - A platelet count presenting with a ____% decrease from the baseline may signal HIT, even if its within the reference interval - (Antigen/Antibody) tests such as ELISA, rapid test, and coagulation-based tests are performed to check for the presence of the HIT complex

1. 30% 2. Antigen

# Platelet Disorders (Quantitative: Thrombocytopenia) Tests for Heparin-Induced Thrombocytopenia (HIT) - Refers to the mixing of washed platelets (PRP) with the radioactive variant of this chemical in order to be absorbed - Upon adding a plasma sample of a patient suspected to have HIT, if the complex is present, it will activate the platelet leading to the release of this - This is measured using a scintillation counter

Serotonin-Release Assay

# Platelet Disorders (Quantitative: Thrombocytopenia) Tests for Heparin-Induced Thrombocytopenia (HIT) What is the gold standard test for HIT?

Serotonin-Release Assay

# Platelet Disorders (Quantitative: Thrombocytopenia) Tests for Heparin-Induced Thrombocytopenia (HIT) PRP is mixed with a plasma sample from a patient suspected of having HIT and the (+) result is the presence of platelet aggregates

Heparin-induced Platelet Aggregation Test (HIPA)

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune - Similar to HDN wherein the mother is (-) for the platelet antigen but the baby is (+) - If there is an interaction, the mother will produce antibodies (IgGs) against the baby’s antigens which will then cross the placenta and attack the baby’s cells

Neonatal Alloimmune Thrombocytopenia

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune - This may appear at birth but manifests as hemorrhage later on in life - Patients can recover within a 1-2 week period - Corticosteroids (immunosuppressants) dampen the immune activity of the mother to prevent further production of antibodies

Neonatal Alloimmune Thrombocytopenia

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune - The mother has an autoimmune condition such as ITP or SLE (e.g. antinuclear antibodies) - The IgGs may cross the placenta and affect the platelets - Platelet count may appear decreased/normal at birth and may progress for about several weeks (1 to 2 weeks or several months) before it increases

Neonatal Autoimmune Thrombocytopenia

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune - The development of platelet antibodies after receiving platelets containing blood products - Is generally self-limiting and may recover after 21 days but 10-15% of patients have been reported to have died

Post-Transfusion Purpura (PTP)

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune In blood banking practice, it is better to have the platelet source come from who to prevent the production of antibodies?

1 person (single platelet donation through apheresis)

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune If antibodies against platelets are already present but the patient is in dire need of transfused platelets, perform this test

HLA compatibility (with ABO as the minimum compatibility requirement)

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune The phenomenon of despite receiving platelets through donation, the patient’s platelet count is still decreased due to antibodies

Platelet Refractoriness

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Immune Familiarize yourself with the antibodies against platelet antigens

1. P1A1 (HPA-1a) 2. P1A2, Bak-a and Bak-b 3. Pen-a 4. Yuk 5. Br-a

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Non-Immune - Presents with blood vessels producing many clots which impedes blood flow leading to damaged platelets due to turbulence - Schistocytes and fragmented RBCs (due to the squeezing) can also be seen in the PBS

Microangiopathic Syndromes

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Non-Immune What is the hallmark for Microangiopathic Syndromes?

Schistocytes in the PBS

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Microangiopathic Syndromes - There is a lack of ADAMTS-13, a disintegrin and metalloprotease with a thrombospondin type 1 motif - It controls the activity of vWF by fragmenting and cutting it during times of platelet adhesion

Thrombotic Thrombocytopenic Purpura (TTP)

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Microangiopathic Syndromes - E. coli OH serotype: 0157-H7 binds or produces a Shiga-like toxin (SLT-1 or 2) that leads to damaged renal vessels - The bacteria can attach using their pili which damages the vessel walls leading to the formation of a clot alongside increased blood urea

Hemolytic Uremic Syndrome (HUS)

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Microangiopathic Syndromes - A form of consumptive coagulation (it consumes clotting factors, fibrinogen, and platelets) - There is activation of the clotting mechanism secondary to trauma, infection, disease, or post-pregnancy

Disseminated Intravascular Coagulation (DIC)

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Other Causes These two (2) conditions can be due to lordosis

1. Pre-eclampsia 2. Gestational thrombocytopenia

# Platelet Disorders (Quantitative: Thrombocytopenia) Increased Platelet Destruction: Other Causes Refers to thrombus development confined within the liver (similar with DIC)

Hemolysis, Elevated Liver enzymes, and Low Platelet count (HELLP) Syndrome

# Platelet Disorders (Quantitative: Thrombocytopenia) Abnormal Distrubution - 70% of platelets are circulating in the blood while 30% are sequestered in the spleen - If the spleen enlarges, more platelets will be sequestered/stored in the spleen leading to decreased platelet count in the blood

Increased Platelet Sequestration

# Platelet Disorders (Quantitative: Thrombocytopenia) Abnormal Distrubution It induces the pooling of platelets to the site of injury therefore decreasing the number of circulating platelets

Kasabach-Merritt Syndrome

# Platelet Disorders (Qualitative: Disorders of Surface Membranes) A defect in GPIIB/IIIA which is important for normal platelet aggregation

Glanzmann-Thrombasthenia

# Platelet Disorders (Qualitative: Disorders of Surface Membranes) - A defect in the GP1B95 complex which is important for normal platelet adhesion - Can be considered both a quantitative and qualitative platelet disorder

Bernard-Soulier Syndrome

# Platelet Disorders (Qualitative: Disorders of Surface Membranes) TOF: If a patient is unresponsive to Ristocetin, it can also be due to VWF disease, not just Bernard-Soulier Syndrome

True

# Platelet Disorders (Qualitative: Disorders of Surface Membranes) Refers to the impairment in the cleavage of the contractile microtubules (cytoskeleton) for the release of platelet granules

Caplain Defect

# Platelet Disorders (Qualitative: Disorders of Surface Membranes) This can be due to the ff. conditions: - Autoantibodies against GP IIb/IIIa - Paraproteins against GP IIIa making platelet aggregation impossible - Afibrinogenemia

Thromabasthenia-like Conditions

# Platelet Disorders (Qualitative: Disorders of Surface Membranes) In Platelet-type VWD, a patient tests positive or negative for Bernard-Soulier Syndrome?

Positive (+)

# Platelet Disorders (Qualitative: Disorders of Platelet Secretion) Can manifest as problems with either the alpha or dense granules

Storage Pool Disease

# Platelet Disorders (Qualitative: Disorders of Platelet Secretion) Storage Pool Disease: Alpha or Dense Granules? Gray Platelet Syndrome

Alpha Granules

# Platelet Disorders (Qualitative: Disorders of Platelet Secretion) Storage Pool Disease Refers to the cytoplasmic color of platelets after staining it with Wright’s stain

Gray Platelet Syndrome

# Platelet Disorders (Qualitative: Disorders of Platelet Secretion) Storage Pool Disease: Alpha or Dense Granules? - Leads to unresponsiveness to aggregating agents even with a normal platelet count - A response to the agents will only produce primary waves, not secondary waves which is still considered deficient

Dense Granules

# Platelet Disorders (Qualitative: Disorders of Platelet Secretion) Familiarize yourself with the 4 conditions associated with dense granule problems in Storage Pool Disease

1. Hermansky-Puldak syndrome 2. Chediak-Higashi syndrome 3. Wiscott-Aldrich syndrome 4. Thrombocytopenia with absent radii (TAR) syndrome

# Platelet Disorders (Qualitative: Disorders of Platelet Secretion) Storage Pool Disease Swiss Cheese Platelet refers to the ____ of platelet microtubules

Dilation

# Platelet Disorders (Qualitative: Disorders of Platelet Secretion) Storage Pool Disease - There is a problem with the development of nitric oxide leading to the digestion of granules and eventual impairment of adhesion - The gene defective in this disorder is responsible for controlling the release of urea

Quebec Platelet Disorder

# Platelet Disorders (Qualitative: Disorders of Receptors and Pathways) A defect in α2β1 (GP Ia/IIa) and GPVI results to poor platelet response for this vessel component

Collagen Receptors

# Platelet Disorders (Qualitative: Disorders of Receptors and Pathways) - Refers to P2X1, P2Y1, and P2Y12 - A lack of G-inhibitory complex formation results in poor response to this substance but with a normal platelet shape change and calcium mobilization

ADP Receptors

# Platelet Disorders (Qualitative: Disorders of Receptors and Pathways) - This is part of the STD receptor - Its defect leads to poor response by the platelets

Epinephrine Receptors

# Platelet Disorders (Qualitative: Disorders of Receptors and Pathways) - Various intracellular signaling defects affect the G-protein sub-unit and the phospholipase C isoenzyme - This specific G-pathway stimulates thrombosthenin to make the platelets contract and release their content

Calcium Mobilization Defects

# Platelet Disorders (Qualitative: Disorders of Receptors and Pathways) - There is a lack of thrombin generation and calcium-induced PL scrambling - Platelet plug formation is normal but the clotting factors have poor assembly on the platelet surface

Scott Syndrome

# Platelet Disorders (Qualitative: Disorders of Receptors and Pathways) This factor is important for platelet shape change to expose the phospholipid which is an important cofactor for Vitamin-K dependent clotting factors

Calcium

# Platelet Disorders (Qualitative: Disorders of Receptors and Pathways) There is a defect in amino phospholipase translocase hence platelets are always in an activated state

Stormorken Syndrome

# Platelet Disorders (Qualitative: Disorders of Receptors and Pathways) This defective enzyme in Stormorken Syndrome is responsible for decreasing cAMP activity which increases ADP leading to platelet activation

Amino Phospholipase Translocase

# Platelet Disorders (Qualitative: Acquired Type) Phosphodiesterase (PDE) is important for the normal formation of ____ and release of ____

1. Formation of Prostaglandin 2. Release of Thromboxane

# Platelet Disorders (Qualitative: Secondary to Other Diseases) Refers to Polycythemia Vera (PV), Chronic Myelogenous Leukemia (CML), Myelofibrosis with Myeloid Metaplasia (MMM), and Essential Thrombocythemia (ET)

Myeloproliferative Neoplasm

# Platelet Disorders (Qualitative: Secondary to Other Diseases) Refers to when platelets are coated with paraproteins

Multiple Myeloma and Waldenstrom Macroglobulinemia

# Platelet Disorders (Qualitative: Secondary to Other Diseases) In Uremia: 1. Excess urea in the blood releases ____ which is a nitric oxide donor 2. The nitric oxide increases ____ inhibiting platelet activation

1. Guanidinosuccinic acid (GSA) 2. Guanylate cyclase

# Platelet Disorders (Qualitative: Secondary to Other Diseases) In uremia, the enzymes are important for the reduction of cAMP activity but since the cAMP will increase in this case, ADP will (increase/decrease) which inhibits platelet function

Decrease

# Platelet Disorders (Qualitative: Secondary to Other Diseases) This causes a defect/lack in platelet aggregation

Hereditary Afibrinogenemia

# Platelet Disorders (Qualitative: Secondary to Other Diseases) In Hyper-Aggregable Platelets: There is a hyper-aggregation response to either ADP or epinephrine

Sticky Platelet Syndrome

# Platelet Disorders (Qualitative: Secondary to Other Diseases) In Hyper-Aggregable Platelets: There is aggregation during in-vitro stirring

Spontaneous Aggregation

(F) Lesson 9: Vascular and Platelet Disorders Flashcards

(108 cards)