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Immunological consequences of splenectomy

Splenectomy, whether a result of blunt force abdominal trauma or specific disease of the spleen, leaves individuals at increased risk for infection. Overwhelming post-splenectomy sepsis (OPSS) is of particular concern in these patients. Encapsulated organisms such as Streptococcus pneumonia, Haemophilius influenza type b, and Neisseria meningitides pose an increased risk for infection. Because the spleen acts as a filter to remove particulate matter and pathogenic bacteria from the blood, bacteria that would normally be opsonized and filtered out by the spleen are not effectively removed. This is compounded by the fact that the spleen, normally inhabited by B cells and phagocytic macrophages, once removed, results in decreased levels of IgM and opsonins and thus a diminished capacity for phagocytosis and clearance of organisms and immune complexes from the body.

Patient education and vaccinations are integral to post-splenectomy prophylactic treatment. Pneumococci and meningococci and H influenza type b are responsible for over 50% of overwhelming sepsis in these patients; therefore, vaccines administration is common. Timing of vaccine administration is a matter of debate. Patient perioperative immunogenicity and decreased immune function are primary concerns. Presplenectomy vaccination is preferred but this is not always an option. Antibodies may not be processed as effectively if vaccines are given too early following surgery so it is general practice to wait 2 weeks post-operatively. The concern with waiting to vaccinate is that it introduces the possibility of the vaccination being missed if the patient is released from the hospital prior to the two week mark or if the patient does not return for the post-operative appointment. Lifelong prophylactic antibiotics are an option but this is highly impractical due to compliance issues and growing antibiotic resistance.

Educating the patient regarding their immunocompromised status and impressing upon them the importance of diligent attention to possible infection impacts morbidity and mortality resulting from infection. Although education alone is not highly reliable, the rapid recognition of possible infection falls to the patient.

Electronic medical records (EMR) assist healthcare providers with the enhanced capability of generating patient reports, treatment guidelines and vaccination reminders. EMR potential for reporting accuracy also increase the likelihood providers will recognize asplenic patients and their particular health needs. Regardless, splenectomy has serious and lifelong immunological implications.

Resources

Recommended Adult Immunization Schedule- United States, 2011; Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report; Feb4, 2011

http://www.cdc.gov/mmwr/PDF/wk/mm6004-Immunization.pdf

Incomplete Care — On the Trail of Flaws in the System; Tejal K. Gandhi, M.D., M.P.H., Gianna Zuccotti, M.D., M.P.H., and Thomas H. Lee, M.D. N Engl J Med 2011; 365:486-488August 11, 2011

http://www.surgicalcriticalcare.net/Guidelines/splenectomy_vaccines.pdf