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Thrombocytopenia
Thrombocytopenia ( 15 Questions)
Which statement accurately describes the pathophysiology of immune thrombocytopenic purpura (ITP)?
"ITP results from decreased platelet production in the bone marrow." Rationale: This statement is not accurate. Immune Thrombocytopenic Purpura (ITP) is primarily a disorder of platelet destruction, not decreased production in the bone marrow. In ITP, autoantibodies target platelets, leading to their destruction by macrophages.
"In ITP, autoantibodies mark platelets for destruction by macrophages." Rationale: This is the correct answer. ITP is an autoimmune disorder where the immune system produces autoantibodies that attach to platelets, tagging them for destruction by macrophages in the spleen and liver.
"ITP is characterized by impaired cleavage of von Willebrand factor." Rationale: This statement is not accurate. Impaired cleavage of von Willebrand factor is a characteristic of von Willebrand disease, a different bleeding disorder, not ITP.
"Thrombocytopenia in ITP is triggered by heparin-platelet factor 4 complexes." Rationale: This statement is incorrect. Heparin-induced thrombocytopenia (HIT) involves the formation of antibodies against heparin-platelet factor 4 complexes, leading to platelet activation and a decrease in platelet count. This is a different condition than ITP.
Choice A rationale:
"ITP results from decreased platelet production in the bone marrow." Rationale: This statement is not accurate.
Immune Thrombocytopenic Purpura (ITP) is primarily a disorder of platelet destruction, not decreased production in the bone marrow.
In ITP, autoantibodies target platelets, leading to their destruction by macrophages.
Choice B rationale:
"In ITP, autoantibodies mark platelets for destruction by macrophages." Rationale: This is the correct answer.
ITP is an autoimmune disorder where the immune system produces autoantibodies that attach to platelets, tagging them for destruction by macrophages in the spleen and liver.
Choice C rationale:
"ITP is characterized by impaired cleavage of von Willebrand factor." Rationale: This statement is not accurate.
Impaired cleavage of von Willebrand factor is a characteristic of von Willebrand disease, a different bleeding disorder, not ITP.
Choice D rationale:
"Thrombocytopenia in ITP is triggered by heparin-platelet factor 4 complexes." Rationale: This statement is incorrect.
Heparin-induced thrombocytopenia (HIT) involves the formation of antibodies against heparin-platelet factor 4 complexes, leading to platelet activation and a decrease in platelet count.
This is a different condition than ITP.