Saturday, 1 January 2011

Anemias and it`s corresponding RBC`s shape

Erythrocytes may have abnormal shapes and sizes in certain diseases.In iron deficiency you would expect to see ?!
  • a.Microcytic, hypochromatic anemia with smaller mature erythrocytes
  • b.Macrocytic, hyperchromatic anemia with fewer, larger mature erythrocytes
  • c.Poikilocytosis and more fragile erythrocytes
  • d.Spherocytosis
  • e.No change in erythrocyte size or shape, but a substantial drop in the hematocrit

The answer is a.
Iron deficiency leads to anemia with the presence of smaller, pale-staining erythrocytes (microcytic, hypochromatic). Hyperchromatic, macrocytic anemia results from vitamin B 12 deficiency (answers b and e).

The presence of spherical rather than biconcave erythrocytes is known as spherocytosis (answer d). The RBC membrane undergoes deformation due to the inability of ankyrin to bind spectrin. The shape change results in trapping in the splenic sinusoids and excessive destruction of red blood cells in that organ. Poikilocytosis is the generic term for abnormally shaped erythrocytes (answer c).
Hereditary elliptocytosis and hereditary poikilo-cytosis are inherited diseases in which there is RBC membrane fragility and abnormal shape due to spectrin mutations. Mutations in Band 3 (anion exchanger 1) result in RBCs that are hyperchromatic with poikilocytosis.

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