Hemolysis
Encyclopedia
Hemolysis—from the Greek (aima, haema, hemo-) meaning "blood" and (lusis, lysis, -lysis) meaning a "loosing", "setting free" or "releasing"—is the rupturing of erythrocytes (red blood cell
s) and the release of their contents (hemoglobin
) into surrounding fluid (e.g., blood plasma
). Hemolysis may occur in vivo or in vitro (inside or outside the body).
hemolysis can be caused by a large number of medical conditions, including many Gram-positive bacteria (e.g., streptococcus
, enterococcus
, and staphylococcus
), some parasites (e.g., malaria
), some autoimmune disorders (e.g., hemolytic disease of the newborn
), and some genetic disorders (e.g., sickle-cell disease
or G6PD deficiency).
cause hemolysis. Streptococcal bacteria species are classified according to their hemolytic properties.
includes lactic acid bacteria formerly classified as beta-hemolytic Group D in the genus streptococcus (see above), including E. faecilis (S. faecalis), E. faecium (S. faecium), E. durans (S. durans), and E. avium (S. avium).
, the most common cause of "staph" infections, is frequently beta-hemolytic.
parasites damages red blood cells, Malaria
is sometimes called "parasitic hemolysis" in medical literature.
.
, jaundice
, and reticulocytosis
. Hemolytic crises are a major concern with sickle-cell disease
and G6PD deficiency.
hemolysis can be caused by improper technique during collection of blood specimens, by the effects of mechanical processing of blood, or by bacterial action in cultured blood specimens.
owing to turbulence and physical forces. Such hemolysis is more likely to occur when a patient's veins are difficult to find or when they collapse when blood is removed by a syringe or a modern vacuum tube. Experience and proper technique are key for any phlebotomist
or nurse to prevent hemolysis.
In vitro hemolysis during specimen collection can cause inaccurate laboratory test results by contaminating the surrounding plasma with the contents of hemolyzed red blood cells. For example, the concentration of potassium
inside red blood cells is much higher than in the plasma and so an elevated potassium level is usually found in biochemistry tests of hemolyzed blood.
In vitro hemolysis can also occur in a blood
sample because of prolonged storage or storage in incorrect conditions (i.e., too hot or too cold).
. A centrifuge process takes blood from the patient, washes the red blood cells with normal saline, and returns them to the patient's blood circulation. Hemolysis may occur if the centrifuge rotates too quickly (generally greater than 500 rpm)—essentially this is hemolysis occurring outside of the body. Unfortunately, increased hemolysis occurs with massive amounts of sudden blood loss, because the process of returning a patient's cells must be done at a correspondingly higher speed to prevent hypotension
, pH
imbalance, and a number of other hemodynamic and blood level factors.
Visualizing the physical appearance of hemolysis in cultured blood samples may be used as a tool to determine the species of various Gram-positive bacteria infections (e.g., streptococcus
).
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...
s) and the release of their contents (hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
) into surrounding fluid (e.g., blood plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
). Hemolysis may occur in vivo or in vitro (inside or outside the body).
In vivo (Inside the body)
In vivoIn vivo
In vivo is experimentation using a whole, living organism as opposed to a partial or dead organism, or an in vitro controlled environment. Animal testing and clinical trials are two forms of in vivo research...
hemolysis can be caused by a large number of medical conditions, including many Gram-positive bacteria (e.g., streptococcus
Streptococcus
Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
, enterococcus
Enterococcus
Enterococcus is a genus of lactic acid bacteria of the phylum Firmicutes. Enterococci are Gram-positive cocci that often occur in pairs or short chains, and are difficult to distinguish from streptococci on physical characteristics alone. Two species are common commensal organisms in the...
, and staphylococcus
Staphylococcus
Staphylococcus is a genus of Gram-positive bacteria. Under the microscope they appear round , and form in grape-like clusters....
), some parasites (e.g., malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
), some autoimmune disorders (e.g., hemolytic disease of the newborn
Hemolytic disease of the newborn
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus, when the IgG molecules produced by the mother pass through the placenta...
), and some genetic disorders (e.g., sickle-cell disease
Sickle-cell disease
Sickle-cell disease , or sickle-cell anaemia or drepanocytosis, is an autosomal recessive genetic blood disorder with overdominance, characterized by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells' flexibility and results in a risk of various...
or G6PD deficiency).
Streptococcus
Many species of the genus StreptococcusStreptococcus
Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
cause hemolysis. Streptococcal bacteria species are classified according to their hemolytic properties.
- Alpha-hemolytic species, including S. pneumoniae, S. mutans, and S. salivarius, reduce the iron in the hemoglobin (turning it dark green in culture).
- Beta-hemolytic species, including S. pyogenes and S. agalactiae, completely rupture the red blood cells (visible as a halo in culture).
- Gamma-hemolytic, or non-hemolytic, species do not cause hemolysis and rarely cause illness.
Enterococcus
The genus enterococcusEnterococcus
Enterococcus is a genus of lactic acid bacteria of the phylum Firmicutes. Enterococci are Gram-positive cocci that often occur in pairs or short chains, and are difficult to distinguish from streptococci on physical characteristics alone. Two species are common commensal organisms in the...
includes lactic acid bacteria formerly classified as beta-hemolytic Group D in the genus streptococcus (see above), including E. faecilis (S. faecalis), E. faecium (S. faecium), E. durans (S. durans), and E. avium (S. avium).
Staphylococcus
Staphylococcus is another Gram-positive cocci. S. aureusStaphylococcus aureus
Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. It is frequently found as part of the normal skin flora on the skin and nasal passages. It is estimated that 20% of the human population are long-term carriers of S. aureus. S. aureus is the most common species of...
, the most common cause of "staph" infections, is frequently beta-hemolytic.
Parasitic hemolysis
Because the feeding process of the plasmodiumPlasmodium
Plasmodium is a genus of parasitic protists. Infection by these organisms is known as malaria. The genus Plasmodium was described in 1885 by Ettore Marchiafava and Angelo Celli. Currently over 200 species of this genus are recognized and new species continue to be described.Of the over 200 known...
parasites damages red blood cells, Malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
is sometimes called "parasitic hemolysis" in medical literature.
Hemolytic disease of the newborn
Hemolytic disease of the newborn is an autoimmune disease resulting from the mother's antibodies crossing the placenta to the fetus.Hemolytic anemia
Because in vivo hemolysis destroys the red blood cells, in uncontrolled chronic or severe cases it can lead to hemolytic anemiaHemolytic anemia
Hemolytic anemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells , either in the blood vessels or elsewhere in the human body . It has numerous possible causes, ranging from relatively harmless to life-threatening...
.
Hemolytic crisis
A hemolytic crisis, or hyperhemolytic crisis, is characterized by an accelerated rate of red blood cell destruction leading to anemiaAnemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
, jaundice
Jaundice
Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia . This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid...
, and reticulocytosis
Reticulocytosis
Reticulocytosis is a condition where there is an increase in reticulocytes, immature red blood cell.It is commonly seen in Anemia. They are seen on blood films when the bone marrow is highly active in an attempt to replace red blood cell loss such as in haemolytic anaemia, haemorrhage.-External...
. Hemolytic crises are a major concern with sickle-cell disease
Sickle-cell disease
Sickle-cell disease , or sickle-cell anaemia or drepanocytosis, is an autosomal recessive genetic blood disorder with overdominance, characterized by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells' flexibility and results in a risk of various...
and G6PD deficiency.
In vitro (lit. "in glass," but generally meaning outside the body)
In vitroIn vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...
hemolysis can be caused by improper technique during collection of blood specimens, by the effects of mechanical processing of blood, or by bacterial action in cultured blood specimens.
From specimen collection
Most causes of In vitro hemolysis are related to specimen collection. Difficult collections, unsecure line connections, contamination, and incorrect needle size, as well as improper tube mixing and incorrectly filled tubes are all frequent causes of hemolysis. Excessive suction can cause the red blood cells to be literally smashed on their way through the hypodermic needleHypodermic needle
A hypodermic needle is a hollow needle commonly used with a syringe to inject substances into the body or extract fluids from it...
owing to turbulence and physical forces. Such hemolysis is more likely to occur when a patient's veins are difficult to find or when they collapse when blood is removed by a syringe or a modern vacuum tube. Experience and proper technique are key for any phlebotomist
Phlebotomist
Phlebotomists are individuals trained to draw blood from a live person or animal.Phlebotomists collect blood primarily by performing venipuncture and, for collection of minute quantities of blood, fingersticks. Blood may be collected from infants by means of a heel stick...
or nurse to prevent hemolysis.
In vitro hemolysis during specimen collection can cause inaccurate laboratory test results by contaminating the surrounding plasma with the contents of hemolyzed red blood cells. For example, the concentration of potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
inside red blood cells is much higher than in the plasma and so an elevated potassium level is usually found in biochemistry tests of hemolyzed blood.
In vitro hemolysis can also occur in a blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
sample because of prolonged storage or storage in incorrect conditions (i.e., too hot or too cold).
From mechanical blood processing during surgery
In some surgical procedures (especially some heart operations) where substantial blood loss is expected, machinery is used for intraoperative blood salvageIntraoperative blood salvage
Intraoperative blood salvage, also known as autologous blood salvage, is a medical procedure involving recovering blood lost during surgery and re-infusing it into the patient....
. A centrifuge process takes blood from the patient, washes the red blood cells with normal saline, and returns them to the patient's blood circulation. Hemolysis may occur if the centrifuge rotates too quickly (generally greater than 500 rpm)—essentially this is hemolysis occurring outside of the body. Unfortunately, increased hemolysis occurs with massive amounts of sudden blood loss, because the process of returning a patient's cells must be done at a correspondingly higher speed to prevent hypotension
Hypotension
In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
, pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
imbalance, and a number of other hemodynamic and blood level factors.
From bacteria culture
Streptococcus
Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
).