Haemolysis, also spelled hemolysis, in biology refers to the destruction or rupture of red blood cells (erythrocytes), leading to the release of their contents (hemoglobin) into the surrounding fluid (e.g., plasma). This process can occur in vivo (within the body) or in vitro (outside the body, such as in a test tube).
Understanding Haemolysis
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Definition: As stated, haemolysis is the breakdown of red blood cells.
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Normal Process: A certain amount of red blood cell destruction is normal and necessary for the body to function. Old or damaged red blood cells are removed and replaced.
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Abnormal Process: However, excessive or premature haemolysis can be a sign of underlying medical conditions.
Causes of Haemolysis
Haemolysis can be caused by a variety of factors, including:
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Genetic Disorders: Examples include sickle cell anemia, thalassemia, and hereditary spherocytosis, all of which affect the structure or function of red blood cells.
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Autoimmune Diseases: In autoimmune hemolytic anemia, the body's immune system mistakenly attacks and destroys its own red blood cells.
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Infections: Certain infections, such as malaria and Clostridium perfringens, can cause haemolysis.
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Drugs and Toxins: Some medications and exposure to certain toxins can damage red blood cells.
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Mechanical Trauma: Physical trauma, such as that experienced by marathon runners (foot strike haemolysis) or patients with prosthetic heart valves, can cause red blood cells to rupture.
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Transfusion Reactions: Incompatible blood transfusions can lead to rapid and severe haemolysis.
Consequences of Haemolysis
Significant haemolysis can lead to:
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Anemia: Reduced number of red blood cells, leading to fatigue, weakness, and shortness of breath.
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Jaundice: Yellowing of the skin and eyes due to the buildup of bilirubin, a byproduct of hemoglobin breakdown.
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Splenomegaly: Enlargement of the spleen as it works to remove damaged red blood cells.
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Hemoglobinuria: Hemoglobin in the urine, making it appear dark or reddish.
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Increased Risk of Blood Clots: Released hemoglobin can contribute to clotting.
In Vitro Haemolysis
Haemolysis can also occur in vitro during blood collection or processing. This can interfere with laboratory tests, leading to inaccurate results. Common causes of in vitro haemolysis include:
- Improper needle gauge
- Vigorous shaking of blood tubes
- Prolonged storage of blood samples at incorrect temperatures
- Contamination of blood samples
In summary, haemolysis is the destruction of red blood cells, a normal physiological process occurring in every human body. However, an elevated rate can lead to other complications.
