This blood test is used to find out whether TTP is the cause of hemolytic anemia. For this test, a sample of blood is drawn from a vein, usually in your arm. In TTP, hemolytic anemia occurs because red blood cells are broken into pieces as they try to squeeze around blood clots.

What are the laboratory findings seen in TTP?

TTP patients usually present with a characteristic set of laboratory findings. This includes a negative direct antiglobulin test (DAT), microangiopathic hemolytic anemia (MAHA), and thrombocytopenia, which are considered major laboratory criterion of TTP.

Is D dimer elevated in TTP?

D-dimers are indicative of fibrinolysis and thus, thrombin activation, which usually is normal or mildly elevated in patients with TTP.