Splenectomy Health Dictionary

Sometimes described as thrombocytopenia, this is an autoimmune disorder in which blood PLATELETS are destroyed. This disturbs the blood’s coagulative properties (see COAGULATION) and spontaneous bleeding (PURPURA) occurs into the skin. The disease may be acute in children but most recover without treatment. Adults may develop a more serious, chronic variety which requires treatment with CORTICOSTEROIDS and sometimes SPLENECTOMY. Should the disease persist despite these treatments, intravenous immunoglobulin or immunosuppressive drugs (see IMMUNOSUPPRESSION) are worth trying. Should the bleeding be or become life-threatening, concentrates of platelets should be administered.... idiopathic thrombocytopenic purpura (itp)

A form of anaemia caused by premature destruction of red cells in the bloodstream (haemolysis). Haemolytic anaemias can be classified according to whether the cause of haemolysis is inside or outside the red cells.

When haemolysis is due to a defect inside the red cells, the underlying problem is abnormal rigidity of the cell membrane. This causes the cells to become trapped, at an early stage of their life-span, in the small blood vessels of the spleen, where they are destroyed by macrophages (cells that ingest foreign particles). Abnormal rigidity may result from an inherited defect of the cell membrane (as in hereditary spherocytosis), a defect of the haemoglobin in the cell (as in sickle-cell anaemia), or a defect of one of the cell’s enzymes. An inherited deficiency of the glucose-6phosphate dehydrogenase enzyme (see G6PD deficiency) may result in episodes of haemolytic anaemia since the red cells are prone to damage by infectious illness or certain drugs or foods.

Haemolytic anaemias due to defects outside the red cells fall into 3 main groups. First are disorders in which red cells are destroyed by buffeting (by artificial surfaces such as replacement heart valves, abnormal blood-vessel linings, or a blood clot in a vessel, for example). In the 2nd group, the red cells are destroyed by the immune system. Immune haemolytic anaemias may occur if foreign blood cells enter the bloodstream, as occurs in an incompatible blood transfusion, or they may be due to an autoimmune disorder. In haemolytic disease of the newborn, the baby’s red cells are destroyed by the mother’s antibodies crossing the placenta. Thirdly, the red cells may be destroyed by microorganisms; the most common cause is malaria. People with haemolytic anaemia may have symptoms common to all types of anaemia, such as fatigue and breathlessness, or symptoms specifically due to haemolysis, such as jaundice.

Diagnosis is made by examination of the blood (see blood film). Some inherited anaemias can be controlled by removing the spleen (see splenectomy). Others, such as G6PD deficiency, can be prevented by avoiding the drugs or foods that precipitate haemolysis. Anaemias due to immune processes can often be controlled by immunosuppressant drugs. Transfusions of red cells are sometimes needed for emergency treatment of life-threatening anaemia.... anaemia, haemolytic

An overactivity of the spleen resulting in, and associated with, blood disease. One of the functions of the spleen is to break down blood cells as they age and wear out. An overactive spleen may begin to destroy cells indiscriminately, causing a deficiency of any of the types of blood cell. In most cases, the spleen will also be enlarged. Hypersplenism may be primary, occurring for no known reason, but more commonly it is secondary to another disorder in which the spleen has become enlarged, such as Hodgkin’s disease or malaria.

Hypersplenism causes anaemia and thrombocytopenia, and there may be a decrease in resistance to infection.

Primary hypersplenism is treated with splenectomy.

Treatment of secondary hypersplenism aims to control the cause.... hypersplenism

An inherited disorder in which there are a large number of unusually small, round red blood cells (spherocytes) in the circulation.

These abnormal red cells are readily broken up when blood passes through the spleen.

At times, the rate of red cell destruction exceeds the rate at which new cells can be made in the bone marrow, leading to symptoms of anaemia.

Other symptoms include jaundice and enlargement of the spleen.

Occasionally, crises occur (usually triggered by infection) in which all symptoms worsen.

Gallstones are a frequent complication.

Splenectomy usually leads to permanent improvement.... hereditary

(ITP) an *autoimmune disease in which platelets are destroyed, leading to spontaneous bruising (see purpura). Acute ITP is a relatively mild disease of children, who usually recover without treatment. A chronic form of the disease, typically affecting adults, is more serious, requiring treatment with corticosteroids or, if there is no response, with splenectomy. If both fail, immunosuppressant drugs may be effective. Platelet concentrates are used for life-threatening bleeding.... idiopathic thrombocytopenic purpura

n. a tetrapeptide derived from IgG (see immunoglobulin), produced mainly in the spleen, that stimulates *neutrophil activity (phagocytosis). Levels of tuftsin are reduced after *splenectomy, resulting in diminished resistance to infection, especially by encapsulated organisms.... tuftsin

An organ that removes worn-out and defective red blood cells from the circulation and helps to fight infection by producing some of the antibodies, lymphocytes, and phagocytes that destroy invading microorganisms. The spleen is a fist-sized, spongy organ in the upper left abdomen behind the lower ribs.

The spleen enlarges in many diseases.

These include infections such as malaria and infectious mononucleosis; blood disorders such as leukaemia, thalassaemia, and sickle cell anaemia; and tumours such as lymphomas.

Enlargement of the spleen may be accompanied by hypersplenism.

The spleen may be ruptured by a severe blow to the abdomen.

This can cause potentially fatal haemorrhage, and an emergency splenectomy is needed.... spleen

A group of inherited blood disorders in which there is a fault in the production of haemoglobin. Many of the red blood cells become fragile and haemolyse (break up), leading to anaemia (see anaemia, haemolytic). Thalassaemia is prevalent in the Mediterranean, the Middle East, and Southeast Asia, and in families originating from these areas.

Normal adult haemoglobin contains 2 pairs of globins (protein chains): alpha and beta. In thalassaemia, a recessive defective gene results in reduced synthesis of 1 of the chains. Usually beta-chain production is disturbed (beta-thalassaemia). Beta-thalassaemia minor (thalassaemia

trait), which is never severe, is caused by 1 defective gene. The presence of 2 defective genes causes beta-thalassaemia major (Cooley’s anaemia). The much rarer disorder alpha-thalassaemia varies in severity; alpha-thalassaemia major usually results in fetal death.

Symptoms of beta-thalassaemia major appear 3–6 months after birth. If untreated, bone marrow cavities expand, leading to a characteristic enlargement of the skull and facial bones.

Beta-thalassaemia major is diagnosed from microscopic examination of the blood, and from other blood tests. Treatment is with blood transfusions and, sometimes, splenectomy. However, successive blood transfusions cause a buildup of iron in the body (see haemosiderosis). Chelating agents are given by continuous infusion to help the body excrete the excess iron. A bone marrow transplant offers a cure for the disease.

Genetic counselling is advised for parents or other close relatives of a child with thalassaemia, and also for any person with thalassaemia trait.... thalassaemia

A reduction in the number of platelets in the blood, resulting in a tendency to bleed. Sometimes thrombocytopenic purpura (abnormal bleeding into the skin) develops. The cause may be a reduced rate of platelet production or fast rate of platelet destruction. Thrombocytopenia can be a feature of leukaemia, lymphoma, systemic lupus erythematosus, megaloblastic anaemia, or hypersplenism. It can also be caused by exposure to radiation or, more often, by an adverse reaction to a prescribed drug such as a thiazide diuretic. Idiopathic thrombocytopenic purpura (ITP) is of unknown cause, but it may be an autoimmune disorder.

Thrombocytopenia is confirmed by a blood count. Any underlying disease is treated if possible. Children with ITP may not need treatment, but adults are usually given corticosteroid drugs. If thrombocytopenia persists, splenectomy may be performed. When the cause is known, treatment usually results in an increase in platelet numbers.... thrombocytopenia