This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Microangiopathic Hemolytic anemia is seen in all Except: 
Select and explain. 
A. TTP, B. Metallic hea valve, C. Microscopic polyangitis, D. Anti-phospholipid syndrome
B: Metallic hea valve
Answer: B: Metallic hea valve 
Explanation: Answer is None or B (None or Metallic Hea Valve) `Metallic hea valves' is the single best answer of exclusion. Pathologically Prosthetic Hea valves are associated with macroangiopathic hemolytic anemias and not microangiopathic hemolytic anemias. TTP, Antiphospholipid syndrome, vasculitis syndromes (including MPA) and mechanical hea valves may all give rise to hemolytic anemia due to red cell fragmentation. Most textbooks do not make a distinction between macroangiopathic and microangiopathic hemolytic syndromes and club all causes into the category of microangiopathic hemolytic anemias (including prosthetic valve hemolytic anemias) However in strict terminology microangippathic hemolytic anemias result from cell fragmentation that occurs in the microcirculation. Red cell fragmentation hemolytic anemias from prosthetic hea valves is strictly/pathologically a macroangiopathic hemolytic anemia and hence the single best answer of exclusion.