An erythrocyte that is larger than average is called a megalocyte or gigantocyte in medical terminology . These large erythrocytes occur almost exclusively as a result of megaloblastic anemia.
A megalocyt is a red blood cell with a shape deviating from the normal shape. Conventional erythrocytes are approximately 7.5 micrometers in diameter. They reach a thickness of two micrometers at the edge and their volume is around 90 fl (femtoliter). The healthy red blood cells show a slight indentation in the middle, which is why they have a biconcave shape.
Megalocytes – gigantocytes
In contrast to the properties of healthy erythrocytes mentioned above, a megalocyte reaches a diameter of more than nine micrometres. In addition, it loses the biconcave shape and assumes an oval geometry without the indentations mentioned. Only the thickness at the edges remains the same as said two micrometers. The volume of a megalocyte reaches over 100 femtoliters due to the increased values.
In addition to the pure numbers, a megalo- cyte differs visually in its color from a healthy erythrocyte. Often the altered red blood cells are hyperchromic. This means: They have an increased color intensity due to an increased hemoglobin content.
Anemia leads to the formation of meglocytes
In most cases, megaloblastic anemia is the trigger for the development of megalocytes. The collective term covers all forms of anemia in which there is a disorder in the bone marrow in the DNA synthesis of the blood-forming cells . This disrupts the development and maturation of red blood cells, causing them to enlarge and grow into megalocytes.
The megaloblastic anemia as the reason for the megalocytes in turn goes back to a lack of folic acid or vitamin B 12 . Humans absorb folic acid through food. The diet in the western world usually covers the need. However, various situations such as pronounced alcoholism, smoking tobacco or replacement therapy for the kidneys promote folic acid deficiency. Risk groups for a vitamin B 12 deficiency are:
- people over the age of 60,
- pregnant women
- Baby,
- chronically ill people.
In summary, a megalocyt develops due to a corresponding anemia. Its causes are in turn based on a lack of folic acid or vitamin B 12 .
Sources and additional resources:
- Changes in erythrocytes, Dr. Thomas Placzek retrieved
- Dr. Stephan, https://www.grossesblutbild.de/megalozyt.html
- de.wikipedia.org/wiki/Megalozyt
