From the Guidelines
The correct answer is (b) hereditary spherocytosis, as it is a defect in the red blood cell membrane that responds to splenectomy by reducing hemolysis and improving anemia. Hereditary spherocytosis is a genetic disorder characterized by defects in red blood cell membrane proteins, particularly spectrin and ankyrin, which connect the membrane to the underlying hemoglobin. These defects lead to abnormally shaped spherical red blood cells that are more rigid and less deformable than normal biconcave red cells. The spleen, which normally filters aged or abnormal red blood cells, recognizes these spherocytes as defective and destroys them prematurely, leading to hemolytic anemia.
Key Points
- Splenectomy is an effective treatment for hereditary spherocytosis because it removes the primary site of red cell destruction, significantly reducing hemolysis and improving anemia in most patients 1.
- Unlike thalassemia or glucose-6-phosphate dehydrogenase deficiency, which involve direct defects in hemoglobin synthesis or red cell metabolism respectively, hereditary spherocytosis involves membrane protein defects that affect the relationship between the cell membrane and hemoglobin.
- Idiopathic thrombocytopenic purpura affects platelets rather than red blood cells and, while it may respond to splenectomy, is not related to hemoglobin chain defects 1.
Considerations
- The decision to perform splenectomy should be based on the individual patient's condition and response to other treatments, as well as the potential risks and benefits of the procedure.
- Splenectomy may be associated with serious short- and long-term risks, including infections, thromboembolism, and possibly an increased incidence of malignancy 1.
- However, in the context of hereditary spherocytosis, the benefits of splenectomy in reducing hemolysis and improving anemia often outweigh the risks, particularly in patients with significant or persistent bleeding and lack of responsiveness to other therapies.
From the Research
Defect in the Hemoglobin Chain that Responds to Splenectomy
- The correct answer is (b) hereditary spherocytosis, as it is a defect in the red blood cell membrane that responds to splenectomy 2, 3, 4, 5.
- Hereditary spherocytosis is a hematologic disorder characterized by hemolytic anemia and splenomegaly, and splenectomy is an effective therapeutic option for this condition 2, 3, 4, 5.
- Splenectomy removes the primary site of red blood cell destruction, eliminating anemia and hyperbilirubinemia, and lowering the high reticulocyte number to nearly normal levels 2, 3, 4, 5.
- The other options, (a) idiopathic thrombocytopenic purpura, (c) thalassemia, and (d) glucose-6-phosphate deficiency, are not directly related to a defect in the hemoglobin chain that responds to splenectomy 6.
- Thalassemia is a defect in the hemoglobin chain, but the effectiveness of splenectomy in this condition has yet to be determined 6.