AACC Hematology & Coagulation 3

Question 1

Which combination of laboratory findings is most characteristic of disseminated intravascular coagulation (DIC)?

Accepted Answer

Decreased platelets, prolonged PT/aPTT, elevated D-dimer, decreased fibrinogen

Answer

Elevated platelets, shortened PT, elevated fibrinogen

Answer

Normal platelets, isolated prolonged aPTT, normal D-dimer

Answer

Elevated platelets, normal PT, elevated fibrinogen, normal D-dimer

Question 2

D-dimer is a specific fibrin degradation product measured in clinical laboratories. What is its primary clinical utility?

Accepted Answer

Ruling out venous thromboembolism (VTE) in low-probability patients

Answer

Confirming the diagnosis of pulmonary embolism

Answer

Monitoring warfarin anticoagulation therapy

Answer

Detecting platelet dysfunction

Question 3

A ristocetin cofactor assay (VWF:RCo) is reduced and VWF antigen is also reduced. What is the most likely diagnosis?

Accepted Answer

Type 1 von Willebrand disease

Answer

Hemophilia A

Answer

Bernard-Soulier syndrome

Answer

Glanzmann thrombasthenia

Question 4

A patient receiving streptokinase therapy for acute myocardial infarction will likely show which laboratory pattern?

Accepted Answer

Prolonged PT/aPTT, decreased fibrinogen, and elevated FDPs

Answer

Elevated platelets and shortened PT

Answer

Markedly elevated fibrinogen and shortened aPTT

Answer

Isolated thrombocytopenia with normal coagulation times

Question 5

What is the normal platelet count reference range in adults?

Accepted Answer

150,000–400,000/μL

Answer

10,000–50,000/μL

Answer

50,000–100,000/μL

Answer

500,000–900,000/μL

Question 6

Which laboratory result would confirm the diagnosis of heparin-induced thrombocytopenia (HIT) type II?

Accepted Answer

Detection of IgG antibodies against the heparin–PF4 complex with clinical thrombocytopenia appearing 5–10 days after heparin initiation

Answer

Prolonged aPTT with thrombocytopenia appearing within 24 hours of heparin exposure

Answer

Negative serotonin-release assay with normal platelet aggregation studies

Answer

Isolated elevation of D-dimer without thrombocytopenia

Question 7

In the evaluation of a microcytic anemia, which set of iron studies distinguishes anemia of chronic disease (ACD) from iron deficiency anemia (IDA)?

Accepted Answer

ACD: high ferritin, low TIBC, low serum iron; IDA: low ferritin, high TIBC, low serum iron

Answer

ACD: low ferritin, high TIBC; IDA: normal ferritin, low TIBC

Answer

ACD: low ferritin, low TIBC, low serum iron; IDA: high ferritin, high TIBC

Answer

ACD: normal ferritin, normal TIBC; IDA: low ferritin, low TIBC