Codocyte

Codocyten, also known as target cells or Mexican Hutzellen ( "Mexican cells has " ) are red blood cells, which have the appearance of a target.

In the light microscope, these cells ( a central area with hemoglobin ), surrounded by a white ring appear to have a dark center (an area that is relatively faint ), followed by a dark outer (peripheral) the second ring, which includes a strip of hemoglobin. In the electron microscope, the Codocyten appear, however, rather very thin and bell-shaped. Due to their small thickness, they are as leptocytisch and because of the wavy head shape as " Mexican cells has " called. On a morphological routine smear some people prefer to distinguish between Leptocyten and Codocyten. They point out that in Leptocyten the central body is not completely separated from the peripheral ring; That is, the pallor is more likely to be seen in a C-shape instead of a complete ring.

The cells are characterized by a disproportionate increase in the ratio of membrane surface area to volume. This is called a " membrane relative surplus ". This is due to the increased surface area of ​​the red blood cells (increase above normal ) or to a decreased intracellular hemoglobin, which in turn can cause an abnormal decrease in the cell volume does not affect the size of the membrane surface. The increase of surface area to volume ratio of the cell gives a decreased osmotic fragility, because it can receive with respect to a given amount of osmotic stress more water.

In vivo, the Codocyten are bell-shaped. Take the targets - configuration only if they are processed to obtain a blood film. In this film, these cells appear thinner than normal, based on the assessment of the thickness by means of a microscope, especially because of their pallor.

Causes

The cells can occur in conjunction with the following phenomena:

• Liver diseases: The lecithin - cholesterol acyltransferase ( LCAT ) activity can be reduced with obstructive liver disease. A reduced enzyme activity, in turn, increased the cholesterol - phospholipid ratio, whereby an increase in surface area of the membranes of red blood cells is caused.
• Iron deficiency: The decrease in the hemoglobin content relative to surface is possibly the reason for the occurrence of Codocyten. The same phenomenon also occurs in thalassemia, hemoglobin C disease on etc..
• α -thalassemia and β -thalassemia ( hemoglobinopathy )
• Hemoglobin C disease
• Post- splenectomy: An important function of the spleen is the elimination of opsonized, deformed and damaged erythrocytes by splenic macrophages. If the splenic macrophage function is impaired or absent due to the removal of the spleen, altered erythrocytes are not efficiently removed from the circulation. Therefore, an increased number of Codocyten observed.
• Autosplenektomie caused by sickle cell anemia

In patients with obstructive liver disease, lecithin - cholesterol acyltransferase activity is weakened, increasing the cholesterol - phospholipid ratio and the surfaces of the membranes of red blood cells increase. In contrast, membrane surplus occurs accordingly in patients with iron deficiency anemia and thalassemia due to the reduced amount of intracellular hemoglobin. If a cell membrane breaks, it is motionless and listened to pulsate on. Forming Codocyten reduces the amount of oxygen which circulates through the blood. You are not able to bind oxygen and transport it to all areas of the body.

Symptoms

Increasing the Codocyten results from a shift in the balance between the red blood cells and cholesterol. As the ratio between surface and volume of the membrane is increased. Codocyten are more resistant to osmotic lysis, which is most commonly seen in dogs. Hypochromic cells in iron deficiency anemia white on the appearance of a target. Codocyten are unusually resistant to saline.