Production Vs. Destruction or Loss
The "kinetic" approach to anemia yields arguably the most clinically relevant classification of anemia. This classification depends on evaluation of several hematological parameters, particularly the blood reticulocyte (precursor of mature RBCs) count. This then yields the classification of defects by decreased RBC production versus increased RBC destruction and/or loss. Clinical signs of loss or destruction include abnormal peripheral blood smear with signs of hemolysis; elevated LDH suggesting cell destruction; or clinical signs of bleeding, such as guaiac-positive stool, radiographic findings, or frank bleeding.
The following is a simplified schematic of this approach:
| Anemia | |||||||||||||||||||||||||||||||||||
| Reticulocyte production index shows inadequate production response to anemia. | Reticulocyte production index shows appropriate response to anemia = ongoing hemolysis or blood loss without RBC production problem. | ||||||||||||||||||||||||||||||||||
| No clinical findings consistent with hemolysis or blood loss: pure disorder of production. | Clinical findings and abnormal MCV: hemolysis or loss and chronic disorder of production*. | Clinical findings and normal MCV= acute hemolysis or loss without adequate time for bone marrow production to compensate**. | |||||||||||||||||||||||||||||||||
| Macrocytic anemia (MCV>100) | Normocytic anemia (80|
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Microcytic anemia (MCV<80) |
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* For instance, sickle cell anemia with superimposed iron deficiency; chronic gastric bleeding with B12 and folate deficiency; and other instances of anemia with more than one cause.
** Confirm by repeating reticulocyte count: ongoing combination of low reticulocyte production index, normal MCV and hemolysis or loss may be seen in bone marrow failure or anemia of chronic disease, with superimposed or related hemolysis or blood loss.
Here is a schematic representation of how to consider anemia with MCV as the starting point:
| Anemia | |||||||||||||||||||||||||||||||||||||||||||||
| Macrocytic anemia (MCV>100) | Normocytic anemia (MCV 80–100) | Microcytic anemia (MCV<80) | |||||||||||||||||||||||||||||||||||||||||||
| High reticulocyte count | Low reticulocyte count | ||||||||||||||||||||||||||||||||||||||||||||
Other characteristics visible on the peripheral smear may provide valuable clues about a more specific diagnosis; for example, abnormal white blood cells may point to a cause in the bone marrow.
Read more about this topic: Anaemic, Classification
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—Lenny Bruce (1925–1966)
“For sleeping, like death,
Must be won without pride,
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And a loss of stature.”
—Philip Larkin (1922–1986)