The reticulocytes

What are reticulocytes?

Reticulocytes are immature red blood cells (called erythrocytes). They no longer have a cell nucleus, but are still able to carry out metabolic processes because some cell organelles are still functional. The endoplasmic reticulum belongs to these cell organelles. In addition, the genetic information (RNA) is stored in the reticulocyte.

Reticulocytes are made in the bone marrow and enter the bloodstream. Maturation in the blood takes place within a day - this is when the RNA and the endoplasmic reticulum are expelled. After this maturation process, the reticulocyte has now become an erythrocyte.

In diagnostics, the number of reticulocytes is of relevance, as it is used to assess bone marrow activity.

The reticulocyte values

The reticulocyte values ​​are given in relation to the erythrocytes (red blood cells): So the number of reticulocytes per 1000 erythrocytes (‰).

The reference range is around 30,000 - 80,000 ul / blood. The reference range can, however, vary somewhat depending on the laboratory and should be taken into account in the evaluation.

The reticulocyte production index

The reticulocyte production index is a more precise value for assessing the maturation process of the erythrocytes. In medical terminology, this maturation process is called erythropoiesis. It is calculated as follows:

(Reticulocyte count in percent x actual hematocrit: shift in days x normal hematocrit of 45)

Two specific factors are taken into account for the calculation - the hematocrit and the reticulocyte shift. The hematocrit describes the proportion of cellular components in the blood. The normal range for women is 33% - 43% and for men 39% - 49%. To determine the index, however, the hematocrit is set at a value of 45%. This makes it easier to compare the values ​​with one another.

The reticulocyte shift, on the other hand, prescribes a shift - there are more reticulocytes in the blood instead of in the bone marrow. The shift is still set depending on the hematocrit.

In healthy people, the value of the reticulocyte production index is one. If there is anemia, you can see whether this is due to a disturbed erythropoiesis. In this case the value is below 2.

In which diseases are reticulocytes increased?

The classic disease that is associated with an increased number of reticulocytes is anemia. Anemia describes anemia. It is characterized by a reduced number of erythrocytes, i.e. a reduced number of red blood cells, or a reduced concentration of the red blood pigment (so-called hemoglobin).

The body tries to compensate for the anemia by the bone marrow producing more reticulocytes and releasing them into the blood. This change becomes noticeable in the blood count as so-called reticulocytosis. In addition, an increased production of reticulocytes speaks against an iron or vitamin deficiency.

Reticulocytosis can also occur after profuse bleeding. Many erythrocytes have died from the bleeding and there is a shortage. The body tries to compensate for this by producing more reticulocytes. After the maturation process, the necessary erythrocytes develop.

Another cause that can lead to increased values ​​is hypoxia. Hypoxia describes a state of insufficient oxygen supply. As a result, the tissue can no longer be adequately supplied with oxygen and goes under. To prevent this condition, the body reacts again with increased production of red blood cells. An increased number of the precursor cells, i.e. the reticulocytes, can be found in the blood count.

Find out more about the topic here: The anemia.

In which diseases are reticulocytes low?

Various diseases are known which lead to a decrease in the number of reticulocytes. For example, chronic kidney failure can cause anemia with reduced reticulocyte counts. The kidney is where the so-called erythropoietin is produced. This is a hormone that acts as a growth factor for the formation of red blood cells (erythrocytes). In the case of renal insufficiency, this hormone is produced less. This in turn leads to a reduced synthesis of red blood cells.

Another disease is myelodysplastic syndrome. The syndrome describes a group of diseases that affect the bone marrow. A blood formation disorder occurs - the erythrocytes are no longer formed from reticulocytes, but from mutated stem cells. Due to the disrupted maturation process of erythrocytes, non-functional cells are now created. However, the blood formation disorder affects not only the erythrocytes, but also blood coagulation. In addition, the neutrophil granulocytes (special cells of the immune defense) may be reduced.

Chemotherapy can trigger the same symptoms of myelodysplatic syndrome regardless of the underlying tumor type. The cause of this is damage to the bone marrow. Due to the loss of function, blood formation can only take place to a limited extent.

In addition, deficiency symptoms such as iron deficiency can lead to a reduced number of reticulocytes. The body is no longer able to maintain blood formation because the necessary nutrients are missing. Percinoid anemia, i.e. anemia caused by a vitamin B12 or folic acid deficiency, also leads to the same symptoms.

These articles might also interest you:

• Percinous anemia
• Chronic renal failure

What is a reticulocyte crisis?

A reticulocyte crisis describes a sharp increase in reticulocytes in the blood. This is due to increased blood formation.

The crisis can arise after profuse bleeding as the body tries to replace the lost blood cells. In addition, it can occur as part of substitution therapy with iron, folic acid or vitamin B12. The increase in reticulocytes suggests an effective therapy.

The iron deficiency

Iron is an important trace element for humans and is particularly important for blood formation. Iron deficiency is the most common deficiency symptom and can cause different symptoms depending on the severity.

A mild deficiency leads to a slight reduction in red blood cells. In the case of a pronounced deficiency, anemia develops with the classic symptoms such as paleness, tiredness and poor concentration. The cells can no longer be adequately supplied with oxygen due to the lack of red blood cells or the lack of hemoglobin (red blood pigment). The symptoms can be treated well through substitution therapy with iron.

Find out all about the topic here: The iron deficiency.

The malaria

Malaria is a tropical infectious disease caused by parasites. These parasites are so-called plasmodia, which attack human erythrocytes. They lead to the destruction of the erythrocytes and can trigger anemia, i.e. anemia. In addition, they lead to a reduction in platelets, which play an essential role in blood clotting.

The body tries to compensate for the loss of erythrocytes by increasing blood formation activity. As a result, the number of reticulocytes in the blood also increases.

Malaria is treated with special drugs such as chloroquine. If the anemia is severe, a blood transfusion may even be necessary.

Find out more about the topic here: Malaria.