Red blood cells, also called erythrocytes or red blood cells, are blood cells essential for oxygenating the body. They transport respiratory gases such as oxygen or O2 and carbon dioxide or CO2.
During a blood test, red blood cell levels are particularly monitored.
What are its characteristics? What can be their anomalies? What is anemia? How to treat it? Elements of response.
Blood cells: what are the characteristics of red blood cells?
Red blood cells, also called erythrocytes or red blood cells, are blood cells essential for oxygenating the body.
Like leukocytes (white blood cells) and thrombocytes (platelets), red blood cells, also called red blood cells, are cells circulating in the blood. These cells have this ability thanks to their particular shape which gives them great elasticity and good resistance.
Red blood cells have a biconcave disc shape with a diameter of about 7 micrometers. This particular shape is explained by the absence of a nucleus in its center.
Red blood cells are recognizable by their red color. It is these cells that give our blood the red coloration. This color explains why they are also called red blood cells or erythrocytes. The latter term comes from the Greek words erythros meaning red and kutos meaning cell.
Red blood cells owe their red color to the presence of hemoglobin within their structure. Hemoglobin is a red pigment, which also has the role of fixing oxygen to transport it to the different tissues of our body.
Red blood cells are synthesized in the bone marrow. Their formation requires a complex process, which is called erythropoiesis. Red blood cells are derived from several cellular mechanisms from undifferentiated stem cells. This production is governed by a hormone: erythropoietin or EPO, which is often best known for its use as a doping agent.
Erythropoiesis allows the synthesis of several hundred billion red blood cells per day, at a rate of 2 to 3 million per second. This high rate of production makes it possible to continuously renew red blood cells at the end of their life. Their lifespan is estimated at 120 days.
A vital role?
Oxygenation of the body
Red blood cells have a key role in the body, ensuring the transport of respiratory gases including oxygen, or O2, and carbon dioxide, or CO2.
Red blood cells participate in the oxygenation of the body thanks to hemoglobin. Present in red blood cells, this molecule has the ability to fix and then release oxygen. This gas essential to life is collected in the lungs and then transported to the different regions of the body.
Transport of carbon dioxide
After transporting oxygen to the tissues, red blood cells are able to collect carbon dioxide thanks to an enzyme present on their surface: carbonic anhydrase. Carbon dioxide can thus be returned to the lungs, where it can then be evacuated from the body.
Red blood cells: what associated pathologies?
During a blood test, different abnormalities can be found. These can affect, in particular:
- the size of red blood cells, with small red blood cells or microcytosis, or large red blood cells or macrocytosis;
- the shape of red blood cells, with, for example, the presence of sickle cell cells;
- the concentration of red blood cells, with too low or too high levels of red blood cells.
Anemia and low blood cells
This abnormality is characterized by an abnormally low level of red blood cells. Anemia can have many causes:
- Iron deficiency anemia: A diet low in iron can lead to the formation of small red blood cells. This is called microcytic anemia;
- vitamin deficiency anemia: Vitamin B12 deficiency can lead to the formation of large red blood cells. This is called vitamin B12 deficiency anemia or macrocytic anemia;
- hemorrhagic anemia: significant blood loss can cause red blood cell deficiency;
- hemolytic anemia: it is due to the too-rapid destruction of red blood cells;
- Aplastic anemia: This is caused by insufficient synthesis of red blood cells.
Polycythemia and elevated red blood cells
Unlike anemia, polycythemia is characterized by an abnormally high level of red blood cells. It is due to excessive production of red blood cells, which can occur:
- in the event of internal or external aggression;
- during certain diseases such as polycythemia vera. This chronic disease can lead to the formation of a blood clot or thrombosis.
This rare genetic disease causes morphological abnormalities in red blood cells. These have a sickle shape. It is for this reason that sickle cell anemia is also called sickle cell anemia or sickle cell anemia.
Diagnosis: the different examinations of red blood cells
The blood count makes it possible to carry out a qualitative and quantitative measurement of the elements present in the blood, including red blood cells. Low red blood cells or high red blood cells?
The interpretation of the results of a blood test helps prevent or diagnose an abnormality. A blood count is sometimes accompanied by a measurement of the sedimentation rate of red blood cells.
The myelogram measures the production of red blood cells through the study of the bone marrow.
Cytobacteriological examination of urine or E.C.B.U.
The presence of red blood cells in the urine can also be assessed by cytobacteriological examination. A high level of red blood cells in the urine can be a pathological sign.
Treatment and prevention of anemia
Prevention of anemia
Some types of anemia can be prevented. For example, iron deficiency anemia can be prevented with adequate iron intake. It is also necessary to fight against the risk of vitamin deficiency through a healthy and balanced diet.
Treatment of anemia
Some forms of anemia can be treated with certain medications or dietary supplements. In particular, nutritional supplementation may be recommended in cases of deficiency anemia.
Treatment of severe anemia
In case of severe anemia, may be necessary:
- a bone marrow transplant;
- a blood transfusion
The same applies in the case of sickle cell disease.
Fun fact: the link between red blood cells and blood types
The determination of blood groups is based on the study of red blood cells.
Indeed, blood groups are established according to the presence or absence of certain antigens on the surface of red blood cells.
In the ABO system, group AB corresponds for example to the presence of antigen A and antigen B.