An enzyme-linked immunosorbent assay (ELISA) with platelet factor ...

[Frost2351]

An enzyme-linked immunosorbent assay (ELISA) with platelet factor 4 (PF4) coated to the surface of microplate wells is used for the diagnosis of:
 
  a. Heparin-induced thrombocytopenia
  b. Acute immune thrombocytopenic purpura
  c. Chronic immune thrombocytopenic purpura
  d. Aspirin resistance

Question 2

The terms petechiae, purpura, and ecchymoses all describe:
 
  a. Varying degrees of thrombocytopenia
  b. Varying degrees of thrombocythemia
  c. Varying qualitative platelet disorders
  d. Varying size hemorrhages into the skin because of small-vessel bleeding

[joewallace]

Answer to Question 1

ANS: A
An ELISA with PF4 coated to the surface of microplate wells is used for the diagnosis of heparin-induced thrombocytopenia. The principle of this test is based on the fact that the antigenic target of the heparin-dependent antibody is a PF4-heparin complex.

Answer to Question 2

ANS: D
These terms all refer to small-vessel bleeding into the skin that is caused by thrombocytopenia or many of the qualitative platelet disorders. Petechiae are small pinpoint hemorrhages, purpura are about 1 cm in diameter, whereas ecchymoses are 3 cm or larger.