What is Microangiopathic Hemolytic Anemia?

By William Aird

A process of red blood cell destruction within the microvasculature; seen in:

  • Thrombotic microangiopathies
  • Valve hemolysis
  • Foot strike anemia

Up-to-Date: MAHA is a descriptive term for non-immune hemolysis (Coombs-negative hemolysis) resulting from intravascular red blood cell fragmentation that produces schistocytes on the peripheral blood smear. Abnormalities in the microvasculature, including small arterioles and capillaries, are frequently involved. However, intravascular devices such as a prosthetic heart valve or assist devices may also cause MAHA. Characteristic laboratory data are a negative direct antiglobulin (Coombs) test (DAT), an increased lactate dehydrogenase (LDH), increased indirect bilirubin, and low haptoglobin.