Hemostasis Coagulation Practice Test

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• In the Clauss fibrinogen assay, the time to clot formation in plasma is measured after the addition of which reagent?
• Protein C and its cofactor Protein S proteolytically inactivate which coagulation factors?
• In an Ashkenazi Jewish patient with a family history of abnormal bleeding, deficiency in which factor is most likely?
• If a prenatal specimen shows thrombocytopenia with platelet clumps on smear, what is the next step in handling the sample?
• Which substrate is converted to fibrin by thrombin?
• Which disease presents with a quantitative platelet disorder?
• Excess D-dimer levels indicate that clots have been
• The most potent plasminogen activator in the contact phase of coagulation is:
• In hemophilia management, which product is a newer option for replacement therapy?
• A 60-year-old man presents with a painful right knee and a slightly enlarged spleen. Which diagnosis is most compatible?
• An elderly patient on long-term warfarin presents with hematuria and a prolonged PT. What is the quickest way to correct the PT?
• Which laboratory test is commonly used to monitor LMWH therapy?
• Type IIb von Willebrand disease is associated with which pattern in ristocetin-induced platelet aggregation at low dose?
• Which finding is characteristic of acute DIC?
• Which factor is the most labile in routine testing when factor assays are delayed after initial PT and aPTT?
• The best test to determine if a sample contains residual heparin:
• Vitamin K deficiency most prominently prolongs which coagulation test?
• In a patient diagnosed with amyloidosis, deficiency of which coagulation factor is typically observed?
• In liver disease, which factor level is typically increased?
• What is the primary function of alpha-2 antiplasmin?
• Results of a Factor X assay are presented. These results indicate the presence of:
• A 70-year-old female with metastatic ovarian carcinoma shows elevated PT and aPTT, platelets 15,000/mm^3 and an elevated D-dimer. The differential diagnosis should include:
• A pregnant woman who is short of breath: based on pregnancy status, the results appear:
• A 65-year-old man with metastatic pancreatic carcinoma shows elevated PT and aPTT, platelets 15x10^3/µL, and elevated D-dimer. A blood smear would show:
• Vasoconstriction is caused by several regulatory molecules. Which pair correctly represents mediators of vasoconstriction?
• In acute idiopathic thrombocytopenia purpura (ITP), which statement is true?
• Which event marks the transition from initiation to propagation in the cellular-based model?
• In a DRVVT workup where the screen is 75 seconds and the confirm is 38 seconds, the normalized ratio is approximately which value?
• A multimer pattern with all bands present but in decreased concentrations would be diagnosed with which von Willebrand disease type?
• Which statement best describes the role of plasmin in hemostasis?
• Which pair of factors differentiates liver disease from vitamin K deficiency?
• A patient presents with an aPTT of 49 seconds (25-35 seconds). A mixing study results indicate: 1:1 mix - 39.8 seconds; pooled normal plasms = 32.0 seconds; incubated mix 1 hour = 39.0 seconds. The results indicate:
• A deficiency of protein C is associated with which of the following?
• How does tissue factor pathway inhibitor inhibit coagulation?
• The major serine protease responsible for clot breakdown is:
• In heparin-induced thrombocytopenia (HIT), the first step in treatment is:
• Which condition is a quantitative platelet disorder?
• Protein S forms a reversible complex with which molecule?
• The life span of a platelet is:
• The type of bleeding that is most characteristic in patients with platelet disorders is which?
• Which disorder is defined by defective GPIIb/IIIa leading to impaired platelet aggregation with multiple agonists but normal ristocetin response?
• Biological assays for antithrombin (AT) are based on the inhibition of:
• Bernard-Soulier syndrome is due to a defect in the platelet glycoprotein Ib-IX-V complex, leading to which laboratory finding?
• In thromboelastography, which sequence is reported to describe the progression of clot formation and dissolution?
• Which enzyme converts plasminogen to plasmin?
• In thrombotic thrombocytopenic purpura (TTP), deficiency of ADAMTS13 causes clotting because of:
• In the Clauss fibrinogen method, the time to clot formation in plasma is measured after the addition of:
• A newborn with homozygous protein C deficiency is at risk for which condition?
• Which characteristic helps distinguish Bernard-Soulier syndrome from von Willebrand disease?
• Which statement correctly describes aspirin's mechanism of action?
• Which statement best describes the clinical significance of isolated Factor XII deficiency?
• A patient presents with a Factor VIII level of 2% and von Willebrand factor activity (ristocetin cofactor) <1% with a vWF antigen of 3%. The most likely diagnosis is:
• Alloantibodies are found in which condition?
• Which of the following will not affect the PFA-100 closure time?
• Which subendothelial protein triggers coagulation by activating factor VII?
• A patient develops unexpected bleeding with laboratory results suggestive of disseminated intravascular coagulation. What is the most probable underlying condition?
• Which statement is true regarding Bernard-Soulier syndrome and von Willebrand disease?
• In lupus anticoagulant screening, which reagent best demonstrates lupus anticoagulant tendency?
• In an aPTT mixing study, which result best indicates a circulating anticoagulant?
• A patient is taking 10 mg per day of Coumadin (warfarin). The results of which of the following lab tests will be most impacted?
• Antithrombin inhibits factors:
• In distinguishing liver disease from vitamin K deficiency, which factor pair is used?
• The tracing shown represents a patient with which von Willebrand disease status?
• A 74-year-old male with repeatedly prolonged aPTT values corrects on mixing studies but has no bleeding history despite multiple surgeries. Which factor is most likely deficient?
• Which deficiency is classically associated with warfarin skin necrosis when starting anticoagulation?
• A patient with positive family history of bleeding and abnormal lab results is likely deficient in which factor?
• Warfarin therapy affects certain coagulation factors. Which set of factors is affected?
• Which of the following is a common feature of von Willebrand disease?
• A patient presents with excessive bleeding. He recently had antibiotic therapy for a streptococcal infection and had previously taken aspirin. The coagulation results point to which likely cause of bleeding?
• In the cellular-based model of coagulation, what occurs during the initiation phase?
• Activation of plasminogen to plasmin resulting in degradation of fibrin occurs by which agent?
• The results from a patient are shown in the table. These results reflect which anticoagulant?
• Patients with homozygous protein C deficiency are at especially high risk of developing which condition?
• The measurement principle that uses a fixed concentration of factor Xa added to patient plasma and a substrate is called which type of assay?
• Spontaneous bleeding occurs when the platelet count is:
• In hemophilia patients, inhibitor development is most likely to occur after exposure to which of the following?
• Isolated prolonged PT that corrects with mixing is most consistent with a deficiency in which factor?
• In liver disease, decreased synthesis occurs for which group of coagulation factors?
• D-dimers are produced from plasmin-mediated degradation of which structure?
• A shortened aPTT can be explained by the presence of which of the following?
• In renal dysfunction, uremia can cause which of the following platelet abnormalities?
• In the cell-based model of coagulation, initiation and amplification is driven by which surface?
• Bleeding does not correlate well with factor levels in a deficiency of which coagulation factor?
• An infant develops petechiae within hours of birth and has a platelet count of 21,000/µL. The most likely diagnosis is:
• Ristocetin cofactor activity is a functional assay for which protein?
• The International Sensitivity Index (ISI) is determined by comparing the PT results of the manufacturer’s reagent against which reference thromboplastin?
• In HIT, antibodies are produced against which molecule?
• D-dimers are produced from which structure?
• A platelet aggregation tracing appears to confirm the diagnosis of Glanzmann thrombasthenia in a patient presenting with a platelet disorder. How would these tracings look if they were performed using light transmittance optical density aggregation?
• Which condition is NOT associated with abnormal initial platelet adhesion to the subendothelial matrix?
• Disorders of platelet aggregation are found in:
• Dysfibrinogenemia is best described by which finding?
• A new PT reagent has an ISI of 1.0 vs a previous ISI of 2.1. The new reagent is said to be:
• Which factor is involved in cross-linking the fibrin clot?
• Von Willebrand factor serves as a stabilizer for which of the following?
• A patient on anticoagulants has a prolonged thrombin time but a normal fibrinogen level. This pattern may indicate which possibility?
• Which pattern of coagulation test abnormalities is typical in vitamin K deficiency?
• What is the most common cause of inherited thrombophilia?
• INR of 3.1 in a patient with a mechanical valve on warfarin implies which action regarding anticoagulation?
• The initial platelet adhesion to subendothelial matrix proteins is abnormal in which conditions?
• A 25-year-old male with celiac disease presents with occult positive stools. What vitamin deficiency should be considered?
• Hemophilia B is a sex-linked recessive disorder that presents with a decrease in factor:
• Acquired hemophilia is best described as which type of disease?
• In HIT, antibodies are produced against which molecule?
• Unregulated and excessive formation of thrombin and plasmin is seen in which condition?
• In the cellular-based coagulation model, which statement describes the propagation phase?
• Ristocetin cofactor assay evaluates the function of which protein?
• A type 1 antithrombin deficiency patient will present with which combination of antigen and activity?
• A patient is placed on clopidogrel. The agonist which would result in a decreased aggregation pattern would be:
• APC resistance is confirmed by the molecular test for:
• Which test provides appropriate lab confirmation of immune mediated heparin induced thrombocytopenia (type 2)?
• To monitor LMWH therapy, which laboratory assay is preferred?
• Heparin resistance is most likely to occur with a deficiency of which protein?
• Which statement about ISI is true?
• If a blood sample shows suspected platelet clumping on automated counting, which anticoagulant should be used when recollecting the sample?
• Patients may present with either a bleeding or thrombotic event in which condition?
• Which statement correctly differentiates thrombin time from reptilase time?
• Which disorder would produce an isolated abnormal aPTT?
• Which subtype of von Willebrand disease is most common?
• Which of the following types of von Willebrand disease should not be treated with DDAVP?
• Occasional spontaneous bleeding may occur in a hemophiliac who is classified as which severity?
• An 11-year-old girl presents with recurrent knee hemarthrosis after an injury. Coagulation studies show prolonged prothrombin time (PT) with a normal activated partial thromboplastin time (aPTT), and the PT corrects toward normal with a mixing study. Which coagulation factor deficiency is most likely?
• Reptilase time is relatively insensitive to which interfering agent?
• ADAMTS13 deficiency is responsible for thrombocytopenia found in which condition?
• Quantitative platelet disorders can be due to:
• If a prolonged aPTT does not correct with mixing, which explanation is most likely?
• In DIC, which laboratory finding is most characteristic?
• If a Factor X assay shows an inhibitor, which interpretation is most likely?
• A 67-year-old female in ICU with positive blood cultures. The differential diagnosis should include which of the following?
• To distinguish between hemophilia and von Willebrand disease, which test result supports von Willebrand disease over hemophilia?
• Factor XIII deficiency most often presents with delayed bleeding tendency.
• Von Willebrand factor mediates platelet adhesion by binding to which platelet receptor complex?
• In hemolytic uremic syndrome, patients present with:
• A lupus anticoagulant can cause bleeding due to antibodies against which coagulation precursor?
• Which of the following characteristics are common between Hermansky-Pudlak and Chediak-Higashi syndromes?
• Which receptor on platelets corresponds to binding collagen?
• Post-transfusion is a rare form of:
• Which of the following platelet responses is most likely associated with type IIb von Willebrand disease?
• Which protein provides the binding site for heparin?
• In patients who present with bleeding disorders caused by platelets, the most common type of bleeding is:
• Hemophilia A is due to a deficiency of which coagulation factor?
• In hemolytic disease of the newborn, affected infants most commonly present with which finding?
• Which condition is most likely associated with giant platelets on a peripheral smear?
• The principle of platelet aggregation is based on which of the following?
• Which statement is true about von Willebrand disease subtypes in terms of prevalence?
• Which mechanism best explains autoimmune neonatal thrombocytopenia?
• In HELLP syndrome, patients typically present with:
• The platelet disorder characterized by a defect in platelet aggregation due to a deficiency of the GPIIb/IIIa complex is:
• In a mixing study, failure to correct after mixing with normal plasma most strongly suggests which of the following?
• A patient has FVIII level of 2%, ristocetin cofactor activity <1%, and von Willebrand factor antigen of 3%. Which von Willebrand disease type is most likely?
• In a dilute Russell viper venom test (DRVVT) workup, a screen of 62 seconds and a confirm of 49 seconds yield which final ratio?
• In a lupus anticoagulant workup, which additional test is commonly performed after a positive dilute Russell Viper Venom Test?
• Which laboratory finding is most consistently prolonged in Warfarin therapy?
• Which pattern of aggregation results supports Glanzmann thrombasthenia?
• Which of the following is not an inherited vascular defect?
• In a 10-year-old male with bruising and deep bleeding, an elevated aPTT that does not correct with a mixing study suggests which diagnosis?
• Which statement best describes acute ITP?
• A patient with renal impairment: which DOAC should be avoided?
• Which statement describes Glanzmann thrombasthenia in platelet aggregation testing?
• A 69-year-old male has abnormal PT and aPTT that completely correct to normal with a mixing study. Which factor deficiency is most likely responsible?
• Which statement best describes a plasminogen activator in the context of the contact phase?
• Post-transfusion thrombocytopenia is best described as:
• An orthopedic patient is placed on low molecular weight heparin after back surgery, in order to determine if the level of LMWH is therapeutic the test to monitored levels would be:
• APC resistance is confirmed by molecular test for which mutation?
• When a patient starts warfarin, which factor decreases first?
• Activated protein C resistance is commonly associated with a mutation in which factor?
• Giant platelets on a blood smear may indicate which disorder?
• TFPI primarily inhibits coagulation by blocking which complex?
• A lupus anticoagulant can cause bleeding due to antibodies against which molecule?
• In severe hemophilia, the factor VIII level is typically below which threshold?
• Lower International Sensitivity Index (ISI) values indicate what about reagent sensitivity, and what would be the effect on PT?
• A 48-year-old male screened pre-operatively who is Ashkenazi Jewish descent; The most likely deficiency is in which factor?
• Which coagulation factor is commonly elevated in liver disease?
• In thromboelastography, the tracing measures which sequence of events?
• A 65-year-old man after valve replacement experiences a rapid fall in platelets with swelling of a limb; what should be investigated and what therapy is indicated?
• In a hemophiliac patient with spontaneous bleeding, the usual level of Factor VIII is:
• A young child with chronic ear infections on prophylactic antibiotics presents with a bleeding diathesis. Which deficiency is most likely?
• Which pairing matches a factor with its related bleeding disorder?
• Which test is used to evaluate the presence of lupus anticoagulant in many coagulation panels?
• vWF antigen can be found in which of the following?
• Which condition is primarily an isolated autoimmune destruction of platelets, presenting with mucocutaneous bleeding and normal coagulation studies?
• Which molecule mediates platelet adhesion to damaged vessels by binding to the GPIb receptor?
• Type III von Willebrand disease is characterized by which level of von Willebrand factor?
• Dabigatran is the direct oral anticoagulant that should be avoided in patients with renal impairment.
• Which finding is most indicative of heparin-induced thrombocytopenia after exposure to heparin?
• In a patient with factor V Leiden mutation, the expected factor V activity level is:
• The DRVV (dilute Russell viper venom) screen test will be prolonged if the reagent contains which of the following?
• If a patient has an aPTT of 62.5 seconds with the only decreased factor being factor XII, what is the typical clinical bleeding history?
• A patient presents with a platelet count of 223x10^9/L with an abnormal PFA most possibly suggest:
• A mixing study will remain uncorrected in a patient who has which condition?
• If a coagulation study shows that a mixing test fails to correct a prolonged aPTT, which explanation is most likely?
• In type 1 antithrombin deficiency, which combination of antigen and activity would you expect?
• A male with siblings who have had multiple DVTs and PEs undergoes a hypercoagulable workup. Which test should be considered next?
• Which molecule acts as a natural inhibitor of plasmin?
• In Glanzmann thrombasthenia, which statement about ristocetin-induced aggregation is true?
• ADAMTS13 deficiency is associated with which condition?
• In DIC, which coagulation parameter changes would you expect?
• A postoperative patient with oozing due to dilutional effects, most likely bleeding cause?
• A patient is on unfractionated heparin after surgery and has an elevated aPTT, but develops a DVT. The best test to monitor anticoagulation is:
• A patient with a mechanical heart valve on warfarin has an INR of 3.1. The anticoagulant level should be:
• When evaluating a patient for von Willebrand disorder, the ABO blood type that has the lowest level of vWF is which?
• Wiskott-Aldrich syndrome typically presents with which combination?
• Which test is commonly used to screen for lupus anticoagulant due to its sensitivity to phospholipid-dependent reactions?
• In the cell-based model of coagulation, the intrinsic pathway operates on which surface to generate the burst of thrombin?
• Large blue inclusion bodies in white blood cells are found in patients with which condition?
• Which of the following best represents the 3 steps of normal hemostasis (in order)?
• Which agent directly activates plasminogen by binding to it in fibrinolysis?
• When there is a disparity between fibrinogen antigen and activity, the most likely diagnosis is which?
• A 40-year-old female presents with mucocutaneous bleeding and severe thrombocytopenia unresponsive to steroids. The most likely diagnosis is:
• Which factor serves as the carrier for factor VIII?
• In liver disease, there is decreased synthesis of which group of coagulation factors?
• Which panel of tests provides the most information in the diagnosis of DIC?
• Which syndrome is associated with oculocutaneous albinism?
• The platelet aggregation tracing shown in the figure represents:
• One of the main differences between TTP and HUS is:
• A 60-year-old female presents with blurred vision, confusion, and petechiae with a platelet count of 29,000/µL. The smear shows schistocytes. The differential should include:
• The aPTT is a coagulation screening test that is also used to:
• To distinguish Hemophilia B from Hemophilia A, a patient with Hemophilia B would present with which coagulation profile?
• If thromboelastography tracing is normal with regard to von Willebrand disease, which diagnosis is most likely?
• An elderly patient with multiple myeloma develops bruising and hematuria. PT is normal, but aPTT and thrombin time are prolonged and do not correct with a mixing study. Fibrinogen and reptilase times are normal. This pattern is most consistent with which cause?
• In secondary hemostasis, prior to activation, their inactive proenzymes are known as:
• Among coagulation tests, which has been associated with mortality in COVID-19?
• Which element is included in the propagation phase of the in vivo coagulation model?
• APC resistance is most commonly due to a mutation in which factor?
• Protein S forms a reversible complex with which molecule (alternative wording)?
• In suspected heparin-induced thrombocytopenia after surgery, what is an appropriate initial management step?
• Arterial thrombosis is primarily associated with which components?
• Elevated D-dimer levels most directly indicate which process?
• Which of the following tests are the most beneficial tool to aid in the diagnosis of DIC?
• Which laboratory test is most sensitive to vitamin K dependent factor deficiencies?
• Which platelet surface antigen acts as the receptor for fibrinogen?
• Which symptom is not traditionally part of the thrombotic thrombocytopenic purpura pentad?
• What is the main role of tissue factor in the initiation of coagulation?
• Factor XII deficiency is associated with which clinical observation?
• Which thrombophilia most often presents with thrombotic episodes that show resistance to heparin therapy?
• Which of the following does the secondary wave of platelet aggregation represent in response to biphasic low-dose ADP and epinephrine?
• An aPTT result of 67 seconds is later repeated as 37 seconds after sample handling. This can be caused by:
• Across the DIC spectrum, which presentation is seen in acute DIC but not typically in chronic DIC?
• Which test is typically prolonged by heparin therapy?
• Aspirin impairs platelet function by which mechanism?
• During pregnancy, PT and aPTT are normal, and fibrinogen is elevated due to the acute-phase response. Which other coagulation factor is commonly elevated in this setting?
• Which of the following is most affected by initial warfarin therapy among the listed proteins?
• Bleeding in a patient recently on antibiotics is most commonly due to which deficiency?
• Factor XIII deficiency presents with which characteristic feature?
• Which laboratory pattern is most consistent with Factor XIII deficiency?
• The anticoagulant that directly inhibits thrombin is:
• A patient with a laceration repaired in the ED returns 15 hours later with excessive bleeding; PT, aPTT, fibrinogen, and platelets are normal. The most likely diagnosis is:
• A 58-year-old male with proximal venous thrombosis is treated with low molecular weight heparin (LMWH). Three days later, which is the expected aPTT result?
• Which receptor acts as the receptor for fibrinogen?
• Students with Wiskott-Aldrich syndrome present with which combination?
• Which of the following platelet antigens act as the receptor for collagen?
• A patient has a clot and laboratory findings consistent with a dysfibrinogenemia. Which diagnosis best fits this profile?
• Protein S deficiency Type II is characterized by which of the following combinations?
• Ticlopidine and clopidogrel inhibit platelets by which mechanism?
• When a patient has an elevated factor VIII level, which test is typically shortened?
• A coagulation sample drawn from a line shows a normal PT, prolonged aPTT, and prolonged thrombin time. What testing step is most appropriate first?
• Alpha granules are found on the platelet in which zone?
• A coagulation reagent is considered sensitive to factor deficiencies. A reagent is sensitive to a factor when the factor activity is approximately what percentage?
• Aspirin affects platelet function by interfering with platelet metabolism of:
• Which hematologic condition is associated with an elevated platelet count?
• Which pairing correctly describes GPIb activation in vivo and in vitro?
• A patient that has a lupus anticoagulant may bleed due to:
• The key enzyme of the fibrinolytic system is:
• A FXI assay yields different values at different dilutions: 1:10 23%; 1:20 42%; 1:140 80%. This pattern is most consistent with which reason?
• Bleeding 48 hours after tooth extraction is most likely due to deficiency of which factor?
• In PV, the platelet count is typically:
• D-Dimer testing is primarily used to assess which of the following?
• Hageman factor XII is involved in all of the following reactions except:
• New oral anticoagulant apixaban has been given to a patient who was previously on warfarin. This drug directly inhibits:
• Which factors are considered heat labile?
• Platelet aggregation will occur with the end production of:
• Which statement best describes features often seen with rare bleeding disorders?
• The most common cause of bleeding in patients is which of the following?
• Which test is used to quantitate a factor inhibitor?
• A patient presents with a low protein S activity and low total and free protein S antigens. The C4b binding protein is normal. This is classified as:
• Which of the following statements is most characteristic of Factor XII deficiency?
• Which statement best describes thromboelastography as a clinical test?
• What is the inheritance pattern of factor IX deficiency?
• In Type II von Willebrand disease, pattern of von Willebrand factor antigen and ristocetin cofactor activity is:
• Which vWD type shows enhanced ristocetin-induced aggregation activity?
• A patient has been taking aspirin regularly for arthritic pain. Which one of the following tests is most likely to be abnormal in this patient?
• Which statement correctly identifies Hemophilia B?
• An anti-Xa assay is performed on a patient taking Lovenox and yields 0.9 U/mL. This anti-Xa level is best described as:
• The differential diagnosis for a child with mucocutaneous bleeding, normal platelet count, and abnormal platelet function tests should include which condition?
• What is the most common presentation of Factor XIII deficiency?
• A hemophilic male and a normal female can produce which of the following?
• A thromboelastography tracing of a cardiac surgery patient most consistent with which condition during surgery?
• Which laboratory diagnosis is most consistent with abnormal fibrinogen function?
• Alloantibodies are typically found in which bleeding disorder?
• In Amyloidosis, deficiency of which coagulation factor is commonly observed?
• Factor XII deficiency is typically associated with which bleeding history?
• Which carrier protein stabilizes Factor VIII in plasma?
• Which anticoagulant is best directed against platelets?
• Which statement best describes the Bethesda assay?
• A patient with a lupus anticoagulant may experience bleeding due to antibodies to which molecule?
• Delayed bleeding is a hallmark of deficiency of which coagulation factor?
• A 42-year-old male presents with fatigue and abnormal coagulation results but no bleeding symptoms. Which condition could explain this finding?
• What does the D-Dimer assay detect?
• A pediatric patient with prolonged PT and abnormal aPTT, and a mixing study that does not correct, should prompt consideration of:
• An inhibitor of plasmin activity is which of the following?