Platelet cells are vital components of blood. Among other functions, the main role of platelets is to prevent excessive bleeding from external and internal wounds. The cells attach to the site of a wound to form a barrier, causing blood to clot. Severe health problems can occur if platelets do not function properly, or there are simply not enough of them in the blood to promote clotting. There are several different types of platelet disease that can be caused by infections, immune system malfunctions, or genetic abnormalities that result in too few or too many platelets. The most common types of platelet disease are thrombocytopenic purpura (TCP), hemolytic uremic syndrome (HUS), Von Willenbrand disease, and thrombocytosis.
Thrombocytopenia refers to an abnormally low platelet count, as determined by a person's doctor. A person with thrombocytopenia is at risk of excessive bleeding and bruising, and severe cases can lead to hemorrhaging. It is usually the result of the body not producing enough platelets, or the immune system mistakenly destroying healthy platelet cells. Diseases that affect the production of new platelets include HIV and bone marrow cancer. Immune system malfunctions can result in TCP, HUS, or other more rare types of platelet disease.
TCP and HUS are types of platelet disease that occur when antibodies are produced by the immune system that attack the platelets. The causes are usually unknown, but some cases are tied to bacterial or viral infections. HUS is more common in children, while TCP typically affects adults over the age of 60. After doctors make a diagnosis of TCP or HUS, they usually prescribe corticosteroids to promote better immune system functioning. An emergency situation where bleeding cannot be stopped may necessitate a blood transfusion to replenish the blood's supply of platelets.
Some types of platelet disease are the result of congenital disorders. Von Willenbrand disease is one of the most common genetic conditions affecting platelet functioning. A very specific genetic mutation inhibits the production of the Von Willenbrand protein. Without the protein, platelets are not able to stick to the walls of wounds and promote clotting. Severe cases of Von Willenbrand disease can lead to severe hemorrhaging if it is not controlled by medications. This platelet disease cannot be cured, but doctors can prescribe a variety of medications that can eliminate symptoms and allow people to lead normal lives.
Thrombocytosis is a condition in which the body produces too many platelets. It can be caused by a bone marrow disorder, a viral infection, or a severe inflammatory disease. In most cases, overproduction of platelets does not lead to any negative symptoms or health effects. In rare instances, however, the blood may unexpectedly start to clot in the extremities or in the brain. A clot can restrict blood flow and rob the body of oxygen, which can lead to permanent brain damage. Thrombocytosis is usually controlled by treating the underlying cause, though emergency surgery may be needed to break up clots.