Leptocytes and target cells

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Leptocytes and target cells

  • The peripheral blood smear of HbH disease presented before is reviewed in the upper photograph.
  • As mentioned, these leptocytes are pale-staining with hemoglobin confined to a thin, flat, cell membrane.
  • Illustrated in the lower photograph are target cells or codocytes (a term derived from a Greek word for hat)
  • Membrane accumulations of phospholipids and cholesterol (particularly in obstructive jaundice) promote target cell formation.
  • When these cells are spread out on a glass slide, a central bump of hemoglobin appears to produce the target, a manifestation of excess cellular membrane compared to the amount of hemoglobin inside.
  • The early descriptions of thalassemias, then called hereditary leptocytosis (Mediterranean anemia, Cooley's anemia), include description of leptocyes, which may have represented HbH disease.