Anisocytosis is a term for a blood abnormality. Anisocytosis occurs when there is a difference in size between several blood cells in the same cell line, such as red blood cells (erythrocyte anisocytosis) and platelets (platelet anisocytosis).
What is anisocytosis?
Anisocytosis is a term used in hematology when there is a size abnormality between blood cells of the same cell line such as:
- red blood cells also called red blood cells or erythrocytes;
- blood platelets also called thrombocytes.
What are the different types of anisocytosis?
It is possible to distinguish several anisocytosis depending on the cell line concerned:
- erythrocyte anisocytosis when the abnormality concerns erythrocytes (red blood cells);
- platelet anisocytosis, sometimes called thrombocytic anisocytosis, when the abnormality involves thrombocytes (blood platelets).
Depending on the type of abnormality found, anisocytosis is sometimes defined as:
- aniso-microcytosis, more often abbreviated to microcytosis, when blood cells are abnormally small;
- anisomacrocytosis, more often abbreviated to macrocytosis, is when blood cells are abnormally large.
How to detect anisocytosis?
Anisocytosis is a blood abnormality identified during a blood count, also called a Complete Blood Count (CBC). Performed by taking a venous blood sample, this examination provides a lot of data on blood cells.
Among the values obtained during a blood count, the red blood cell distribution index (RDI) is also called the anisocytosis index. Allowing us to evaluate of the variability of the size of red blood cells within the bloodstream, this index makes it possible to identify erythrocyte anisocytosis. It is considered normal when it is between 11 and 15%.
What causes anisocytosis?
Generally speaking, anisocytosis is a term used by doctors to refer to erythrocyte anisocytosis. Regarding red blood cells, this blood abnormality is usually due to anemia, an abnormal drop in the level of red blood cells or hemoglobin in the blood. This deficiency can lead to complications because red blood cells are essential cells for the distribution of oxygen within the body. Present in red blood cells, hemoglobin is a protein capable of binding several oxygens (O2) molecules and releasing them at the cell level.
It is possible to distinguish several types of anemias causing erythrocyte anisocytosis, including:
- iron deficiency anemia, caused by iron deficiency, is considered microcytic anemia because it can lead to aniso-microcytosis with the formation of small red blood cells;
- vitamin deficiency anemia, the most common of which is vitamin B12 deficiency anemias and vitamin B9 deficiency anemias, which are considered macrocytic anemias because they can cause anisomacrocytosis with the production of large deformed red blood cells.
- hemolytic anemia, characterized by premature destruction of red blood cells, which can be caused by genetic abnormalities or diseases.
Platelet anisocytosis also has a pathological origin. Platelet anisocytosis can be due to myelodysplastic syndromes (MDS), which are a set of diseases due to bone marrow dysfunction.
What are the symptoms of anisocytosis?
The symptoms of anisocytosis are those of anemia. Although there are different forms and origins of anemia, several characteristic symptoms are frequently observed:
- a feeling of generalized fatigue
- shortness of breath
- weakness and dizziness
How to treat anisocytosis?
Treatment of anisocytosis depends on the cause of the abnormality. In case of iron deficiency anemia or vitamin deficiency anaemia, nutritional supplementation may for example be recommended to treat anisocytosis.