Immune-mediated haemolytic anemia (IMHA) is a condition in which the body’s immune system produces antibodies against its own red blood cells, resulting in their destruction. This can cause a decreased number of red blood cells, known as anaemia, as well as other complications. The exact cause of IMHA is not known, but it is thought to be related to an underlying infection, autoimmune disorder, or drug reaction.
Pathogenesis
The pathogenesis of IMHA is complex and not fully understood. It is thought to be an immune-mediated process in which the body produces antibodies against its own red blood cells. These antibodies attach to the red blood cells, causing them to be destroyed by the body’s immune system. This results in the release of hemoglobin, a component of red blood cells, into the bloodstream. The hemoglobin is then broken down, resulting in anaemia.
Immune System Activation
The body’s immune system is activated when it detects the presence of the antibodies attached to the red blood cells. This triggers a cascade of events that result in the destruction of the red blood cells. This process is known as “complement-mediated lysis” and involves the activation of enzymes that break down the red blood cell membrane.
Risk Factors
There are several risk factors for IMHA, including certain infections, medications, and autoimmune disorders. People with a weakened immune system (such as those with HIV/AIDS or cancer) are also at increased risk.
Diagnosis
The diagnosis of IMHA is based on clinical signs and symptoms, as well as laboratory tests. Common signs and symptoms include pale skin, jaundice, fatigue, and dark urine. Laboratory tests, such as a complete blood count (CBC) and a blood smear, can help to confirm the diagnosis.
Treatment
Treatment for IMHA is aimed at reducing the destruction of red blood cells and restoring their normal levels. This can involve medications to suppress the immune system, antibiotics to treat any underlying infection, and blood transfusions to replace lost red blood cells. In some cases, surgery may be necessary to remove the spleen, which is responsible for the destruction of red blood cells.
