Microangiopathic hemolytic anemia 488689 206768483 2008-04-19T21:53:22Z 141.214.37.185 /* Causes */ {{Infobox_Disease | Name = {{PAGENAME}} | Image = | Caption = | DiseasesDB = 29721 | ICD10 = {{ICD10|D|59|4|d|55}} | ICD9 = {{ICD9|283.19}} | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshID = }} In [[medicine]] ([[hematology]]) '''microangiopathic hemolytic anemia''' (MAHA) is a subgroup of [[hemolytic anemia]] ([[anemia]], loss of red blood cells through destruction) caused by factors in the small blood vessels. It is identified by the finding of anemia and [[schistocytes]] on [[light microscopy|microscopy]] of the [[blood film]]. ==Presentation== In diseases such as hemolytic uremic syndrome, disseminated intravascular coagulation, thrombotic thrombocytopenic purpura, as well as malignant hypertension, the endothelial layer of small vessels are damaged with resulting fibrin deposition and platelet aggregation. As red blood cells travel through these damaged vessels, they are shredded. The result is red cell fragmentation and intravascular hemolysis. Under the microscope, damaged red cells have the appearance of schistocytes. [[Automated analyser]]s (the machines that perform routine [[full blood count]]s in most hospitals) are generally programmed to flag blood films that display red blood cell fragments or ''schistocytes''. ==Causes== The most important causes are: * [[Aortic stenosis]] (most common cause of MAHA) * [[Thrombotic thrombocytopenic purpura]] (TTP) * [[Hemolytic uremic syndrome]] (HUS) * [[Disseminated intravascular coagulation]] (DIC) * [[HELLP syndrome]] and [[eclampsia]] * [[Heparin-induced thrombocytopenia]] (HIT) * Severe [[glomerulonephritis]] * Several other rare causes ==Pathophysiology== In all causes, the mechanism of MAHA is the formation of a [[fibrin]] mesh due to increased activation of the system of [[coagulation]]. The red blood cells are physically cut by these protein networks, and the fragments are identical to the schistocytes seen on light microscopy. {{Hematology}} [[Category:Hematology]] [[Category:Nephrology]] {{med-stub}}