There is also a deficiency of T-cell independent antibodies, such as those reactive to the polysaccharide capsule of Streptococcus pneumoniae.The risk to asplenic patients has been expressed as equivalent to an adult dying in a road traffic accident (in every 100 people without spleens, 1 to 5 would develop a severe infection per decade) (reference UK Splenectomy Trust Advice)—hence sensible precautions are advisable. Increased platelet counts can be seen in individuals without a functioning spleen. Diagnosis
Diagnosis is confirmed by abdominal ultrasonography and detection of Howell-Jolly bodies in red blood cells. Management
To minimise the risks associated with splenectomy, antibiotic and vaccination protocols have been established, but are often poorly adhered to by physicians and patients due to the complications resulting from antibiotic prophylaxis such as development of an overpopulation of Clostridium difficile in the intestinal tract. Antibiotic prophylaxis
Because of the increased risk of infection, physicians administer oral antibiotics as prophylaxis after a surgical splenectomy, or starting at birth for congenital or functional asplenia. Those with asplenia are also cautioned to start a full-dose course of antibiotics at the first onset of an upper or lower respiratory tract infection (for example, sore throat or cough), or at the onset of any fever.
Patients who have some form of asplenia have an increased susceptibility to these encapsulated bacterial infections mainly because they lack IgM memory B cells and their non-adherence to polysaccharide vaccines. Furthermore, there is a deficiency of other splenic cells e.g. splenic macrophages. This combined with the lack of B cells can provide an environment favourable for the development of bacterial infections. Partial splenectomy and preservation of splenic function
In an effort to preserve some of the spleens protective roles, attempts are now often made to preserve a small part of the spleen when performing either surgical subtotal (partial) splenectomy, or partial splenic embolization. This may be particularly important in poorer countries where protective measures for patients with asplenia are not available. However, it has been advised that preoperative vaccination is advisable until the remnant splenic tissue can reestablish its function. Risks
Asplenia is a form of immunodeficiency, increasing the risk of sepsis from polysaccharide encapsulated bacteria, and can result in overwhelming post splenectomy infection (OPSI), often fatal within a few hours. In particular, patients are at risk from Streptococcus pneumoniae, Haemophilus influenzae, and meningococcus. The risk is elevated as much as 350–fold.The increased risk of infection is due to inability to clear opsonised bacteria from circulating blood.