Microangiopathic hemolytic anemia
Encyclopedia
In medicine
(hematology
) microangiopathic hemolytic anemia (MAHA) is a microangiopathic subgroup of hemolytic 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 microscopy of the blood film
.
, as well as malignant hypertension, the endothelial layer of small vessels is damaged with resulting fibrin deposition and platelet aggregation. As red blood cells travel through these damaged vessels, they are fragmented resulting in intravascular hemolysis. The resulting schistocyte
s (helmet cells) are also increasingly targeted for destruction by the reticuloendothelial system in the spleen, due to their narrow passage through obstructed vessel lumina. It is seen in systemic lupus erythematosus
because the immune complex aggregates with platelets, which creates intravascular thrombi.
Automated analyser
s (the machines that perform routine full blood counts in most hospitals) are generally programmed to flag blood films that display red blood cell fragments or schistocytes.
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.
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
(hematology
Hematology
Hematology, also spelled haematology , is the branch of biology physiology, internal medicine, pathology, clinical laboratory work, and pediatrics that is concerned with the study of blood, the blood-forming organs, and blood diseases...
) microangiopathic hemolytic anemia (MAHA) is a microangiopathic subgroup of hemolytic anemia
Hemolytic anemia
Hemolytic anemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells , either in the blood vessels or elsewhere in the human body . It has numerous possible causes, ranging from relatively harmless to life-threatening...
(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 microscopy of the blood film
Blood film
A blood film or peripheral blood smear is a thin layer of blood smeared on a microscope slide and then stained in such a way to allow the various blood cells to be examined microscopically...
.
Presentation
It is referred as Runner's anemia. In diseases such as hemolytic uremic syndrome, disseminated intravascular coagulation, thrombotic thrombocytopenic purpuraThrombotic thrombocytopenic purpura
Thrombotic thrombocytopenic purpura is a rare disorder of the blood-coagulation system, causing extensive microscopic thromboses to form in small blood vessels throughout the body...
, as well as malignant hypertension, the endothelial layer of small vessels is damaged with resulting fibrin deposition and platelet aggregation. As red blood cells travel through these damaged vessels, they are fragmented resulting in intravascular hemolysis. The resulting schistocyte
Schistocyte
A schistocyte or schizocyte is a fragmented part of a red blood cell. Schistocytes are typically irregularly shaped, jagged, and asymmetrical. A true schistocyte does not have central pallor...
s (helmet cells) are also increasingly targeted for destruction by the reticuloendothelial system in the spleen, due to their narrow passage through obstructed vessel lumina. It is seen in systemic lupus erythematosus
Systemic lupus erythematosus
Systemic lupus erythematosus , often abbreviated to SLE or lupus, is a systemic autoimmune disease that can affect any part of the body. As occurs in other autoimmune diseases, the immune system attacks the body's cells and tissue, resulting in inflammation and tissue damage...
because the immune complex aggregates with platelets, which creates intravascular thrombi.
Automated analyser
Automated analyser
An automated analyser is a medical laboratory instrument designed to measure different chemicals and other characteristics in a number of biological samples quickly, with minimal human assistance....
s (the machines that perform routine full blood counts in most hospitals) are generally programmed to flag blood films that display red blood cell fragments or schistocytes.
Pathophysiology
In all causes, the mechanism of MAHA is the formation of a fibrinFibrin
Fibrin is a fibrous, non-globular protein involved in the clotting of blood. It is a fibrillar protein that is polymerised to form a "mesh" that forms a hemostatic plug or clot over a wound site....
mesh due to increased activation of the system of coagulation
Coagulation
Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis, the cessation of blood loss from a damaged vessel, wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel...
. The red blood cells are physically cut by these protein networks, and the fragments are identical to the schistocytes seen on light microscopy.