Spleen: Disorders

Abstract The spleen is an important peripheral immunologic organ although not essential for life. The main functions of the spleen are filtering of blood, lymphopoiesis and immunoglobulin production. The spleen is abundantly supplied with blood, which the other secondary lymphoid organs do not have, and clears particulate material, for example, opsonised bacteria from the blood. Reduced function, known as functional asplenia, is observed in many various pathological conditions, for example, when the spleen is congested with blood or when infiltrated by metastatic tumours or contains large haemangiomas. Most common causes of splenic hypofunction are coeliac disease, sprue, sickle cell disease and haematologic disorders. Individuals with removed spleen or impaired splenic function are prone to serious and often fatal bacterial infections. The vast majority of these serious infections, caused by encapsulated bacteria (pneumococci, meningococci and Haemophilus influenzae type b) can be effectively prevented by immunisations and antibiotic prophylaxis. Key Concepts Spleen is an important secondary immunologic organ located in the left epigastrium beneath the lower rib cage, responsible for blood filtration and antibodies production. Spleen is important but not essential for life and can be removed. Reduced spleen function, known as functional asplenia, is observed in various pathological conditions including sickle cell disease, celiac disease and haematologic disorders. Spleen dysfunction is associated with increased risk of serious and sometimes fatal bacterial sepsis or meningitis, usually caused by pneumococci and other capsular bacteria. The vast majority of bacterial infections in asplenic individuals can be prevented by currently available immunisations and prophylactic antibiotics.