Which condition results in autosplenectomy due to fibrosis and shrinkage of the spleen?

Sickle cell anemia is associated with autosplenectomy due to the repeated splenic infarctions caused by abnormal sickling of the red blood cells. In sickle cell anemia, the red blood cells distort into a sickle shape, particularly at low oxygen levels, which increases their viscosity and causes them to obstruct small blood vessels. This leads to a series of vaso-occlusive crises, which can result in ischemia and infarction of the splenic tissue.

Over time, the repeated injury from these occlusions causes fibrosis and shrinkage of the spleen, eventually leading to functional asplenia, or autosplenectomy. The loss of spleen function increases susceptibility to encapsulated organisms, making vaccinations against these pathogens critical for affected individuals.

In contrast, conditions like beta-thalassemia, hemophilia, and aplastic anemia do not typically lead to autosplenectomy through the same process. Beta-thalassemia may result in splenomegaly rather than atrophy, hemophilia is a coagulation disorder with no direct impact on splenic architecture, and aplastic anemia involves bone marrow failure without specific effects on the spleen.