Hematopathology

Note the anisocytosis and several dark-appearing spherocytes with no central pallor. Howell-Jolly bodies (small dark nuclear remnants) are also present in red cells of this asplenic patient.
Hereditary spherocytosis


Pathogenesis: HS is usually caused by defects in: The proteins involved in the vertical interactions between the membrane skeleton and the lipid bilayer of the red cell. Various mutations involving: Spectrin and Ankyrin that weaken the interactions between these proteins cause red cells to lose membrane fragments.


The loss of membrane may be caused by the release of parts of the lipidbilayer that are not supported by the skeleton.