What Is Autoimmune Thrombocytopenia?

Autoimmune thrombocytopenia (AITP) is a medical condition in which the body’s immune system develops antibodies against its own platelets, resulting in thrombocytopenia, or low platelet counts. It can be caused by various conditions, including drug reactions, viral infections and other systemic diseases. In other cases, the disease develops people who are otherwise healthy. Symptoms can include easy bleeding and rashes. Treatment of the condition depends on the reason why it developed.

In general, autoimmune thrombocytopenia occurs when the body produces antibodies against its own platelets, resulting in the destruction of the platelets. These antibodies can be produced in many clinical situations. When certain people take specific drugs, their bodies might react against the drugs and produce antibodies that harm those people's platelets. Similarly, the response to certain viral infections also can cause the production of these antibodies. In other cases, the antibodies are produced idiopathically, or without a specific inciting factor.

Symptoms of autoimmune thrombocytopenia can vary. If the disease is mild, patients might not have any symptoms and might be diagnosed with the condition only when laboratory studies done for other reasons reveal abnormal platelet counts. Other patients could be symptomatic, experiencing easy bleeding from the gums, nosebleeds and skin rashes. If the disease is severe, patients can develop internal bleeding that can be deadly.

Diagnosing autoimmune thrombocytopenia can be complicated. One of the cardinal features of the disease is a low platelet count. It is important for a doctor to differentiate autoimmune thrombocytopenia from other causes of low platelets, so typically it is important for the doctor to elicit a complete history of medical problems, medications taken and any recent illnesses from any patient who has been found to have a low platelet count. Laboratory studies also can be performed in attempts to identify some of the antibodies that are responsible for the destruction of the platelets. Examining the peripheral blood under a microscope, and in some cases examining an aspirated sample of the bone marrow, often can also provide clues toward the diagnosis of this condition.

The treatment of autoimmune thrombocytopenia depends on the reason why the antibodies against the platelets developed. If caused by a drug, the drug should be stopped; if associated with a viral infection, the underlying infection should be treated. In idiopathic cases, depending on the severity of the disease, various treatment options are possible. Mild disease doesn’t require treatment. More severe disease could be treated with therapies such as immunoglobulin administration or plasmapheresis.