Hemolysis

As hemolysis [ hɛmoly zə ː ] is called the resolution of red blood cells, the erythrocytes. We distinguish between the physiological hemolysis after 120 days and the increased hemolysis. The increased hemolysis is associated with a shortened life span of erythrocytes. It comes to anemia, if the degradation of erythrocytes exceeds the compensatory regeneration.

A natural increased degradation takes place directly after birth, since then the fetal erythrocytes have to be dismantled and replaced by erythrocytes for breathing air with oxygen.

As hemolysis also a property of microorganisms is known to degrade erythrocytes. This can be detected using blood agar plates. These can then be distinguished:

  • α - hemolysis ( greening ): The bacteria do not produce hemolysins, they call on blood agar a greenish zone out, which is not due to a real hemolysis, but a discoloration and a loss of potassium in red blood cells. The reduction of hemoglobin to biliverdin causes the green color. It can still be found intact erythrocytes. " α - hemolysis " should not be confused with " α - hemolysins ." The latter are exotoxins (e.g., Staphylococcus aureus ), which may cause osmotic lysis of a cell by the formation of a membrane pore. Are they so in erythrocytes successful, so reach actually a " β - hemolysis ".
  • β - hemolysis: The bacteria produce streptolysin O or S and are surrounded by a clear zone of haemolysis. The hemoglobin is completely broken down, it is this is a real hemolysis. In this area, all erythrocytes are completely hemolyzed.
  • γ - hemolysis: These bacteria show no hemolysis.

Causes

An increased ( pathological ) degradation of erythrocytes ( cell lifespan under 100 days ) one finds

  • In adults: mechanical disturbances ( vascular changes or even in extreme marches )
  • Membrane defects of erythrocytes (such as in sickle cell anemia, according to the action of light in erythropoietic protoporphyria )
  • By infections such as malaria
  • Immunological disorders
  • Toxins (e.g., from Streptococcus, or certain species of spiders )
  • Waldenstrom
  • In neonates ( see life phase) significantly increased degradation within a few hours or days physiologically by increased remodeling of the fetal to " normal " hemoglobin
  • Blood group or Rhesus factor incompatibility between mother and child

If more degraded than erythrocytes are formed, the result is anemia (anemia).

In the degradation of erythrocytes is the result bilirubin, so that with regard to increased degradation also increased bilirubin and can thereby jaundice occur.

Diagnostics

For the avoidance of hemolysis following laboratory parameters are determined:

  • The LDH ( lactate dehydrogenase, the enzyme ), a marker of cell death. In this hemolysis is usually increased.
  • The reticulocyte count ( reticulocytes are young, immature erythrocytes, which are increasingly found in the demise of erythrocytes in the blood. )
  • Indirect bilirubin, which has not yet been conjugated in the liver is increased relatively early in hemolysis.
  • Haptoglobin, a blood -occurring protein which is used to capture free hemoglobin may be lowered.
  • Free, that is, not bound to erythrocytes or hemoglobin haptoglobin in the blood and urine can be found only in severe hemolysis.

Treatment

In acute cases, transfusions of packed red blood cells may be necessary. Otherwise, the causes should be treated as far as possible.

Normal values ​​of erythrocyte number and bilirubin in Article laboratory medicine.

Blood type Clinical pathology
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