The Aplastic Crisis in Hereditary Spherocytosis
Patients who have hereditary spherocytosis (HS) may develop profound anemia following infection with parvovirus B-19. Because the average survival of a spherocyte in patients who have HS is approximately 30 days, sites of hematopoiesis actively compensate for the shortened survival of these cells to maintain a stable hemoglobin level. Hanada and Koike found that parvovirus B-19 invades precursors of red blood cells, white blood cells, and platelets and causes them not to proliferate. Mayman and Zipursky note that this may result in the hemoglobin level falling to half of the steady-state level. For this reason, aplastic crises are extremely dangerous; death may result.