All immune (white blood) cells are made from haematopoietic (blood stem cells) which originate in the bone marrow, hence the name ‘B’ cell. The exception to this are the T cells which are made from blood stem cells which have moved to the thymus to mature; hence the name ‘T’ cell. The spleen is the largest lymph node in the body and has an important role in storing cells including B cells, producing antibodies and removing antibody coated bacteria.

Consider why a patient who has asplenia (no spleen) may be at greater risk of infection.

A patient with no spleen will have reduced number of circulating memory B cells, thereby reducing the ability of the body to recognise and target infection. They will also have a reduced ability to remove identified bacteria even if it is coated with antibodies as the spleen has a major function in filtering the blood.

Why may a patient be vaccinated to common diseases prior to a planned splenectomy?

In order to optimise the function of the existing immune system and increase the number of circulating memory B cells to common diseases, patient who undergo a routine splenectomy are vaccinated with pneumococcal polysaccharide, haemophilus influenza type B and meningococcal conjugate vaccines. This prepares the patient for future infection with these bacteria.

What are the future care implications for a patient who has a splenectomy? 

Asplenia can be considered an immunodeficiency and as such, patients will be at increased risk of infection. Patients should be monitored for early signs of infection. It is standard practice for patients to take prophylactic (preventative) antibiotics permanently, with a low threshold to change to an alternative treatment antibiotic, if a break through infection occurs. Patients should be given the annual, seasonal influenza vaccination to reduce their risk of infection.