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: Pathology
All of the following conditions are associated with coombs positive hemolytic anemia, except: 
Select and explain. 
A. Thrombotic Thrombocytopenic purpura (TTP), B. Scleroderma, C. SLE, D. PAN
A: Thrombotic Thrombocytopenic purpura (TTP)
Answer: A: Thrombotic Thrombocytopenic purpura (TTP) 
Explanation: Thrombotic Thrombocytopenic purpura (TTP), shows coomb's negative microangiopathic hemolytic anemia. Ref: Amit Ghosh, MD (2010), Chapter 11, "Hematology: Benign Hematology", In the book, "Mayo Clinic Internal Medicine Board Review", 9th Edition, New york, Page 378; Harrison's Principles of Internal Medicine, 16th Edition, Page 612