From the Guidelines
Anisocytosis is a condition characterized by the variation in size of red blood cells and should be addressed by treating the underlying cause, which can be identified through a comprehensive evaluation including morphologic and kinetic approaches, as outlined in the study by 1. The morphologic approach categorizes anemia based on the mean corpuscular volume (MCV), with microcytic, normocytic, and macrocytic anemia having different underlying causes, such as iron deficiency, vitamin B12 or folate deficiency, and hemolytic anemias [ 1 ]. Key factors to consider in the evaluation of anisocytosis include:
- Mean corpuscular volume (MCV) to determine if the anemia is microcytic, normocytic, or macrocytic
- Reticulocyte count to assess the bone marrow's production capacity
- Iron and total iron binding capacity (TIBC) to evaluate for iron deficiency
- Vitamin B12 and folate levels to assess for deficiencies
- Tests for hemolysis, such as Coombs test, disseminated intravascular coagulation panel, and low haptoglobin levels The kinetic approach focuses on the underlying mechanism of anemia, distinguishing among production, destruction, and loss of red blood cells, with a reticulocyte index (RI) helping to identify decreased or increased red blood cell production [ 1 ]. Given the variability in causes, treatment should be directed at the specific underlying condition, such as iron supplementation for iron deficiency anemia or vitamin B12 supplementation for B12 deficiency, as indicated by the study [ 1 ].
From the Research
Anisocytosis
- Anisocytosis is a condition characterized by the presence of red blood cells that vary in size 2.
- It is often seen in iron deficiency anemia, where red blood cells show poikilo- and anisocytosis with predominance of small erythrocytes 2.
- Anisocytosis can be measured using red cell volume distribution curves, which are more sensitive than conventional red cell indices for detecting iron deficiency 3.
Diagnosis and Evaluation
- Anisocytosis is often accompanied by other hematological abnormalities, such as microcytosis, which can be used to diagnose and evaluate iron deficiency anemia 3.
- The red blood cell distribution width (RDW) index is also used to diagnose and evaluate anemia, including iron deficiency anemia 4.
- Reticulocyte parameters, such as mean corpuscular volume (MCV) and corpuscular mean hemoglobin concentration of reticulocyte (CHCMr), can be useful in differentiating mixed anemia from vitamin B12 deficiency, iron deficiency anemia, and healthy controls 5.
Stages of Iron Deficiency
- Iron deficiency can progress through three stages, with anisocytosis and microcytosis being the first hematological abnormalities to occur 3.
- At the second stage, the MCV and MCH decline, and hemoglobin concentration is generally sub-normal 3.
- The final stage of iron deficiency is associated with a low MCHC, a hemoglobin concentration below 9 g/dl, and a transferrin saturation of less than 16% 3.