autosplenectomy

Autosplenectomy is the progressive loss of splenic function due to repeated splenic infarctions, leading to a small, fibrotic, often nonfunctional spleen. The term is most commonly used in association with sickle cell disease and other hemoglobinopathies, where chronic vaso-occlusion of the splenic vasculature causes repeated infarcts over years.

In sickle cell disease, splenic infarction begins in early childhood as red blood cell sickling obstructs splenic vessels. Ongoing ischemia and fibrosis gradually replace normal splenic tissue, and by adolescence or early adulthood the organ becomes atrophic and nonfunctional. This end result is functional asplenia, meaning the spleen remains present but no longer performs its filtering and immune roles effectively. Calcification of splenic tissue can occur during this process.

Clinically, autosplenectomy may be preceded by hypersplenism with splenomegaly and cytopenias, but the hallmark is a permanently reduced splenic function. Patients with functional asplenia have an increased susceptibility to infections, particularly with encapsulated organisms such as Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis. Vaccination and prophylactic antibiotics in early life are important preventive measures, and patients with fever or signs of infection require prompt evaluation and treatment.

Diagnosis is typically made by imaging studies showing a markedly small or atrophic spleen, sometimes with calcifications. Functional asplenia is confirmed through clinical context and, when needed, laboratory tests reflecting decreased splenic immune activity.

Management focuses on infection prevention, including appropriate immunization against encapsulated bacteria, consideration of antibiotic prophylaxis in childhood, and patient education on seeking urgent care for fever.