10,37,38 hem

Which of the following is the most common of the hereditary platelet function defects? a. Glanzmann thrombasthenia b. Bernard-Soulier syndrome c. Storage pool defects d. Multiple myeloma

c. Storage pool defects

What is Ehlers-Danlos syndrome?

hyperextensible skin, hypermobile joints, joint laxity, fragile tissues, and a bleeding tendency, primarily subcutaneous hematoma formation. Defect in collagen production, structure, cross linking

ADP receptor

increases calcium levels by inhibiting adenylate cyclase

What is Hereditary hemorrhagic telangiectasia?

thinning vessel walls with discontinued endothelium, inadequate smooth muscle and elastin, dilated superficial blood vessels create small focal reed lesions on lips, tongue, face, hands/fingers, nosebleeds frequent

In uremia, platelet function is impaired by higher than normal levels of: a. Urea b. Uric acid c. Creatinine d. NO

NO

What happens to platelets in renal failure

NO is present in the circulation at higher than normal levels in uremia. NO diffuses into platelets, activates soluble guanylate cyclase, and inhibits platelet adhesion, activation, and aggregation

What plasma protein is essential for platelet adhesion? a. VWF b. Factor VIII c. Fibrinogen d. P-selectin

VWF

What causes acquired thrombocytopenia?

Viral or bacterial infections, Drug induced

What is senile purpura?

a lack of collagen support for small blood vessels and loss of subcutaneous fat and elastic fibers. Seen in elderly, age spots

Thrombocytopenia associated with the use of cardiopulmonary bypass is not caused by: a. Anti-GP IIb/IIIa antibodies b. Hemodilution c. Platelet binding to bypass circuitry d. Platelet consumption associated with normal postsurgical hemostatic activity

a. Anti-GP IIb/IIIa antibodies

HUS in children is associated with: a. Diarrhea caused by Shigella species b. Meningitis caused by Haemophilus species c. Pneumonia caused by Mycoplasma species d. Pneumonia caused by respiratory viruses

a. Diarrhea caused by Shigella species

A defect in GP IIb/IIIa causes: a. Glanzmann thrombasthenia b. Bernard-Soulier syndrome c. Gray platelet syndrome d. Storage pool disease

a. Glanzmann thrombasthenia

The platelet defect associated with increased paraproteins is: a. Impaired membrane activation, owing to protein coating b. Hypercoagulability, owing to antibody binding and membrane activation c. Impaired aggregation, because the hyperviscous plasma prevents platelet-endothelium interaction d. Hypercoagulability, because the increased proteins bring platelets closer together, which leads to inappropriate aggregation

a. Impaired membrane activation, owing to protein coating

Which of the following molecules is stored in platelet dense granules? a. Serotonin b. Fibrinogen c. Platelet factor 4 d. Platelet-derived growth factor

a. Serotonin

Aspirin ingestion blocks the synthesis of: a. Thromboxane A2 b. Ionized calcium c. Collagen d. ADP

a. Thromboxane A2

PAF receptor

activation, shape change, and secretion

Glycoprotein Ia and IIa

adherence of platelets to charged collagen

Glycoprotein Ib-IX-V

adherence to collagen or platelet bound vWF

Thrombospondin receptor

aggregation of platelets

Glycoprotein IIb-IIIA

aggregation of platelets in the presence of fibrinogen, fibrin, fibronectin, and vWF

Factor V receptor

attachment of factor V to platelet phospholipid

Patients with Bernard-Soulier syndrome have which of the following laboratory test findings? a. Abnormal platelet response to arachidonic acid b. Abnormal platelet response to ristocetin c. Abnormal platelet response to collagen d. Thrombocytosis

b. Abnormal platelet response to ristocetin

Which is a congenital qualitative platelet disorder? a. Senile purpura b. Ehlers-Danlos syndrome c. Henoch-Schönlein purpura d. Waldenström macroglobulinemia

b. Ehlers-Danlos syndrome

What platelet membrane receptor binds fibrinogen and supports platelet aggregation? a. GP Ib/IX/V b. GP IIb/IIIa c. GP Ia/IIa d. P2Y1

b. GP IIb/IIIa

The specific antigen most commonly responsible for the development of NAIT is: a. Bak b. HPA-1a c. GPIb d. Lewis antigen a

b. HPA-1a

. A defect in primary hemostasis (platelet response to an injury) often results in: a. Musculoskeletal bleeding b. Mucosal bleeding c. Hemarthroses d. None of the above

b. Mucosal bleeding

When a drug acts as a hapten to induce thrombocytopenia, an antibody forms against which of the following? a. Typically unexposed, new platelet antigens b. The combination of the drug and the platelet membrane protein to which it is bound c. The drug alone in the plasma, but the immune complex then binds to the platelet membrane d. The drug alone, but only when it is bound to the platelet membrane

b. The combination of the drug and the platelet membrane protein to which it is bound

Upon activation, platelets secrete their a-granule contents via: a. The dense tubule system b. The surface connected canalicular system c. The glycocalyx d. Microtubules

b. The surface connected canalicular system

TAR refers to: a. Abnormal platelet morphology in which the radial striations of the platelets are missing b. Abnormal appearance of the iris of the eye in which radial striations are absent c. Abnormal bone formation, including hypoplasia of the forearms d. Neurologic defects affecting the root (radix) of the spinal nerves

c. Abnormal bone formation, including hypoplasia of the forearms

A 2-year-old child with an unexpected platelet count of 15,000/mL and a recent history of a viral infection most likely has: a. HIT b. NAIT c. Acute ITP d. Chronic ITP

c. Acute ITP

A reduction in thrombin generation in patients with Scott syndrome results from: a. Defective granule secretion b. Altered platelet aggregation c. Altered expression of phospholipids on the platelet membrane d. Deficiency of vitamin K-dependent clotting factors

c. Altered expression of phospholipids on the platelet membrane

Which drug causes a reduction in platelet count by inhibiting megakaryocyte maturation? a. Gold salts b. Abciximab c. Anagrelide d. Quinidine

c. Anagrelide

White clots: a. Occur primarily in the deep veins of the leg b. Are characteristic of the secondary hemostatic process c. Are largely composed of platelets and von Willebrand factor d. Form normally in response to vascular injury and are completely harmless

c. Are largely composed of platelets and von Willebrand factor

Microparticles: a. Are stored in platelet dense granules b. Inhibit blood clotting c. Bud off of platelets after their exposure to strong agonists d. Exhibit no biologic activity

c. Bud off of platelets after their exposure to strong agonists

What platelet organelle sequesters ionic calcium and binds a series of enzymes of the eicosanoid pathway? a. Glycocalyx b. Dense granules c. Dense tubular system d. Surface connected canalicular system

c. Dense tubular system

A mechanism of antiplatelet drugs targeting GP IIb/IIIa function is: a. Interference with platelet adhesion to the subendothelium by blocking of the collagen binding site b. Inhibition of transcription of the GP IIb/IIIa gene c. Direct binding to GP IIb/IIIa d. Interference with platelet secretion

c. Direct binding to GP IIb/IIIa

Reticulated platelets can be enumerated in peripheral blood to detect: a. Impaired platelet production in disease states b. Abnormal organelles associated with diseases such as leukemia c. Increased platelet production in response to need d. Inadequate rates of membrane cholesterol exchange with the plasma

c. Increased platelet production in response to need

Which of the following is not a hallmark of ITP? a. Petechiae b. Thrombocytopenia c. Large overactive platelets d. Megakaryocyte hypoplasia

c. Large overactive platelets

The autosomal dominant disorder associated with decreased platelet production is: a. Fanconi anemia b. TAR syndrome c. May-Hegglin anomaly d. Wiskott-Aldrich anomaly

c. May-Hegglin anomaly

What is DIC? What causes it, what are the lab results.

Disseminated intravascular coagulation, consumptive coagulopathy that entraps plts in intravascular fibrin clots. Thrombi are plts and fibrinogen. uncontrolled clotting, microthrombi form and block small vessels, consume plts and coag factors, usually acute What causes it? chronic= necrosis, renal/liver disease, chronic inflammation, vascular tumors, adenocarcinoma. acute= obstetric emergencies, intravascular hemolysis, sepsis, burns, crush injuries. What are the lab results? Plt dec, schistocytes in PB, PT & PTT prolonged, D-dimer inc, fibrinogen dec. treat underlying disorder

What causes acquired platelet dysfunction?

Drugs are the most common cause, also effects of aging, allergic rxns, Hermansky-Pudlak syndrome, Chédiak-Higashi syndrome, Wiskott-Aldrich syndrome, Thrombocytopenia-absent radius (TAR) syndrome

What is Bernard-Soulier syndrome?

Giant plt syndrome, Disorder of plt adhesion caused by the lack of expression of GP Ib/IX/V complexes on the platelet surface, absence results in a severe bleeding disorder. Manifests in childhood, inherited Lab results: enlarged plts, thrombocytopenia, normal aggregation but abnormal with ristocetin and thrombin

What is HUS? What causes it, what are the lab results

Hemolytic uremic syndrome, like TTP but in children, renal dysfunction, mild thrombocytopenia, mild anemia, presentation in children What causes it? Shigella or e. Coli, What are the lab results? Hemolytic anemia, renal failure, thrombocytopenia, elevated BUN & creatinine, urine has rbcs, casts, protein, hgb <10, elevated retics, schistocytes.

What is HIT?, how do we monitor it, how do we test for it?

Heparin induced thrombocytopenia, heparin binds to PF4, causing a conformational change and is now considered "new", stimulates immune system and formation of antibodies PLT F4/heparin complex, more plts will be activated/clot, leads to decrease in plts from them being activated and clotting. How do we monitor it? Check plt counts, 30-50% drop. How do we test for it? Heparin induced antibody immunoassay, aggregometry or lumi aggregometry

What is ITP?

Immune (idiopathic) thrombocytopenic purpura, increased plt destruction by either immune response or mechanical damage, consumption, or sequestration.

What can cause ineffective thrombopoiesis?

Megaloblastic anemias (pernicious anemia, folic acid def, vit b12 def), impaired dna synthesis, viruses (CMV, measles, varicella, EBV), bacterial infections, live virus vaccines, malignant cells in BM

What is TTP? What causes it, what are the lab results

Thrombotic thrombocytopenic purpura. classic pentad of symptoms that includes microangiopathic hemolytic anemia, thrombocytopenia, and neurologic abnormalities, fever and renal dysfunction. What causes it? accumulation of ultralarge von Willebrand factor (ULVWF) multimers in the plasma which are more effective than the normal plasma VWF multimers at binding platelet GPIb/IX or GPIIb/IIIa complexes and will bind spontaneously to platelets to form platelet aggregates, History of viral illness, thrombi produce lesions that cause rbcs and plts to be destroyed. Thrombi are made of plts & VWF. 4 types= single acute episode, recurrent, drug induced (plavix), chronic relapsing. What are the lab results? Schistocytes, intravascular hemolysis, reticulocytosis, hguria, LDH/indirect bili/BUN elevated, decreased hemoglobin, thrombocytopenia

Which of the following statements regarding thrombocytosis is not true? a. Thrombocytosis can be associated with hemorrhage and thrombosis b. Affected patients have platelet counts in excess of 450,000/mL c. Thrombocytosis is self-correcting d. Thrombocytosis can be congenital or acquired

c. Thrombocytosis is self-correcting

Thromboxane A2 and Prostacyclin 1-2 receptor

calcium release from DTS and subsequent release of dense, alpha, and lysosomal granules

Treatment with an anticomplement agent such as eculizumab is first-line therapy for: a. Hereditary TTP b. Hemolytic uremic syndrome (HUS) c. ITP d. Atypical HUS

d. Atypical HUS

The clinical presentation of platelet-related bleeding may include all of the following except: a. Bruising b. Nosebleeds c. Gastrointestinal bleeding d. Bleeding into the joints (hemarthroses)

d. Bleeding into the joints (hemarthroses)

The impaired platelet function in myeloproliferative neoplasms results from: a. Abnormally shaped platelets b. Extended platelet life span c. Increased procoagulant activity d. Decreased numbers of alpha granules and dense granules

d. Decreased numbers of alpha granules and dense granules

The megakaryocyte progenitor that undergoes endomitosis is: a. MK-I b. BFU-Meg c. CFU-Meg d. LD-CFU-Meg

d. LD-CFU-Meg

What platelet membrane phospholipid flips from the inner surface to the plasma surface on activation and serves as the assembly point for coagulation factors? a. Phosphatidylethanolamine b. Phosphatidylinositol c. Phosphatidylcholine d. Phosphatidylserine

d. Phosphatidylserine

What is the name of the eicosanoid metabolite produced from endothelial cells that suppresses platelet activity? a. Thromboxane A2 b. Arachidonic acid c. Cyclooxygenase d. Prostacyclin

d. Prostacyclin

Neonatal autoimmune thrombocytopenia occurs when: a. The mother lacks a platelet antigen that the infant possesses, and she builds antibodies to that antigen, which cross the placenta b. The infant develops an autoimmune process such as ITP secondary to in utero infection c. The infant develops an autoimmune disease such as lupus erythematosus before birth d. The mother has an autoimmune antibody to her own platelets, which crosses the placenta and reacts with the infant's platelets

d. The mother has an autoimmune antibody to her own platelets, which crosses the placenta and reacts with the infant's platelets

The growth factor that is produced in the kidney and induces growth and differentiation of committed megakaryocyte progenitors is: a. IL-3 b. IL-6 c. IL-11 d. Thrombopoietin

d. Thrombopoietin

What are the three causes of thrombocytopenia?

decreased platelet production, increased destruction, or abnormal distribution of platelets

What is Glanzmann thrombasthenia?

disorder of plt aggregation, caused by the lack of expression of GP IIb/IIIa complexes on the platelet surface. This complex is known as the platelet aggregation receptor, severe bleeding disorder. Manifests in infancy, inherited, defect in plt plug formation Lab results: normal plt count & morphology, lack of aggregation

What causes neonatal thrombocytopenia?

disorders of platelet production or increased destruction with origins in either the mother or the neonate. Caused by rubella, CMV, varicella, herpes, toxoplasmosis, lack of megakaryocytes in BM. maternal ingestion of diuretics can have cytotoxic effect on fetal megakaryocytes

chronic ITP

mostly female 20-50 years old, PLT destruction by binding of autoantibodies to plts which are removed from circulation by reticuloendothelial system mostly in the spleen, shortened life span of plts to a few hours, igG antibodies to plts. Lasts months to years, no spontaneous remission

acute ITP

occurs in children after a viral infection or vaccination, abrupt onset of bruising, petechiae, mucosal bleeding, PLT destruction due to binding of immune complexes to PLT surface. Lasts 2-6 weeks, spontaneous remission

What happens to platelets in Multiple Myeloma, Waldenstrom's?

paraprotein coating plts that interfere with fibrin polymerization and function of factors

What are the terms used to describe various sizes of hemorrhages?

petechiae= small pinpoint dots. purpura= middle sized, round red spots. ecchymosis= 1cm or larger, irregular shaped

Epinephrine receptor

platelet activation

Glycoprotein VI

platelet activation, collagen receptor

What does aspirin and Plavix(clopidogrel) do to platelet function?

plavix= ADP blocker, aspirin= cox-1 inhibitor