Overview of the Spleen

Asplenia is loss of splenic function due to

Congenital asplenia is a rare disorder. Infants with this disorder often also have congenital heart disease Overview of Congenital Cardiovascular Anomalies Congenital heart disease is the most common congenital anomaly, occurring in almost 1% of live births ( 1). Among birth defects, congenital heart disease is the leading cause of infant mortality... read more .

Functional asplenia is loss of splenic function due to a variety of systemic diseases. Common causes include sickle cell disease Sickle Cell Disease Sickle cell disease (a hemoglobinopathy) causes a chronic hemolytic anemia occurring almost exclusively in people with African ancestry. It is caused by homozygous inheritance of genes for hemoglobin... read more , celiac disease Celiac Disease Celiac disease is an immunologically mediated disease in genetically susceptible people caused by intolerance to gluten, resulting in mucosal inflammation and villous atrophy, which causes malabsorption... read more , and alcohol-related liver disease Alcohol-Related Liver Disease Alcohol consumption is high in most Western countries. According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), 8.5% of US adults are estimated to... read more . Functional asplenia can also occur after direct vascular insults (eg, splenic infarcts, splenic vein thrombosis).

Surgical asplenia is the physical absence of the spleen. It can occur in otherwise healthy patients who require splenectomy after trauma or in patients with immunologic or hematologic diseases that require splenectomy (eg, immune thrombocytopenia Immune Thrombocytopenia (ITP) Immune thrombocytopenia (ITP) is a bleeding disorder usually without anemia or leukopenia. Typically, it is chronic in adults, but it is usually acute and self-limited in children. Spleen size... read more , hypersplenism Hypersplenism Hypersplenism is cytopenia caused by splenomegaly. (See also Overview of the Spleen.) Hypersplenism is a secondary process that can arise from splenomegaly of almost any cause (see table Common... read more , hereditary spherocytosis Hereditary Spherocytosis and Hereditary Elliptocytosis Hereditary spherocytosis and hereditary elliptocytosis are congenital red blood cell (RBC) membrane disorders that can cause a mild hemolytic anemia. Symptoms, generally milder in hereditary... read more ). Splenic injury after blunt abdominal trauma is common and especially so in contact sport participants. Without appropriate surgical treatment severe and sometimes lethal hemorrhage may occur.

Due to the spleen’s important role in humoral immunity as well as in removal of antibody-coated bacteria, asplenia of any cause significantly increases the risk of infection. Asplenic patients are particularly susceptible to severe sepsis due to encapsulated microorganisms, primarily Streptococcus pneumoniae Streptococcal Infections Streptococci are gram-positive aerobic organisms that cause many disorders, including pharyngitis, pneumonia, wound and skin infections, sepsis, and endocarditis. Symptoms vary with the organ... read more (pneumococcus), but also sometimes Haemophilus influenzae Haemophilus Infections The gram-negative bacteria Haemophilus species cause numerous mild and serious infections, including bacteremia, meningitis, pneumonia, sinusitis, otitis media, cellulitis, and epiglottitis... read more type b (Hib) or Neisseria meningitidis Meningococcal Diseases Meningococci (Neisseria meningitidis) are gram-negative cocci that cause meningitis and meningococcemia. Symptoms, usually severe, include headache, nausea, vomiting, photophobia, lethargy... read more (meningococcus). Patients are also at increased risk of babesiosis Babesiosis Babesiosis is infection with Babesia species of protozoa. Infections can be asymptomatic or cause a malaria-like illness with fever and hemolytic anemia. Disease is most severe in asplenic... read more .

Because of the risk of these infections, immunization is important. Patients should receive the pneumococcal vaccine Pneumococcal Vaccine Pneumococcal disease (eg, otitis media, pneumonia, sepsis, meningitis) is caused by some of the > 90 serotypes of Streptococcus pneumoniae (pneumococci). Vaccines are directed against... read more , the meningococcal vaccine Meningococcal Vaccine The meningococcal serogroups that most often cause meningococcal disease in the US are serogroups B, C, and Y. Serogroups A and W cause disease outside the US. Current vaccines are directed... read more , and the Haemophilus influenzae b vaccine Haemophilus influenzae Type b (Hib) Vaccine Haemophilus influenzae type b (Hib) vaccines help prevent Haemophilus infections but not infections caused by other strains of H. influenzae bacteria. H. influenzae causes... read more . Patients should also receive the influenza vaccine Influenza Vaccine Based on recommendations by the World Health Organization and the Centers for Disease Control and Prevention (CDC), vaccines for influenza are modified annually to include the most prevalent... read more and other vaccinations according to their clinical situation. Patients also are often given daily prophylactic antibiotics such as penicillin or amoxicillin, particularly when they have regular contact with children. The appropriate duration for prophylactic antibiotic use is unclear. Patients with asplenia who develop fever should receive empiric antibiotics while undergoing evaluation for the source.