MAHA

= Microangiopathic haemolytic anaemia
Etiology Disseminated intravascular coagulation, Thrombotic thrombocytopenic purpura, severe aortic stenosis etc... (DIC: clotting factors + platelets stuck together; TTP: networks of platelets; prosthetic valve)
Epidemiology
Clinical presentation See Thrombotic thrombocytopenic purpura
Pathogenesis mechanical shearing of RBCs. TTP can be familial, associated with Shiga toxin (E. coli O157:H7) or idiopathic
Diagnostic investigations Clotting screen: normal
FBC: ↓ Plt, ↓ factor VIII, ↑ retics
Blood film: schistocytes, “helmet cells”
Direct antiglobulin test: +ve (excludes immune
Management ➥ May require dialysis with AKI
➥ AVOID platelets!
➥ Good prognosis if caught early