hemolysis

(hĭmŏl`ĭsĭs), destruction of red blood cells in the bloodstream. Although new red blood cells, or erythrocytes, are continuously created and old ones destroyed, an excessive rate of destruction sometimes occurs. The dead cells, in sufficiently large numbers, overwhelm the organ that destroys them, the spleen, so that serum pigments resulting from hemoglobin breakdown appear in the blood serum. Jaundicejaundice
, abnormal condition in which the body fluids and tissues, particularly the skin and eyes, take on a yellowish color as a result of an excess of bilirubin. During the normal breakdown of old erythrocytes (red blood cells), their hemoglobin is converted into bilirubin.
..... Click the link for more information. is caused by overloading the liver with pigment. Large-scale destruction of red blood cells, from any of a variety of causes, results in anemiaanemia
, condition in which the concentration of hemoglobin in the circulating blood is below normal. Such a condition is caused by a deficient number of erythrocytes (red blood cells), an abnormally low level of hemoglobin in the individual cells, or both these conditions
..... Click the link for more information. . Rh disease, or erythroblastosis fetaliserythroblastosis fetalis
, hemolytic disease of a newborn infant caused by blood group incompatibility between mother and child. Although the Rh factor is responsible for the most severe cases of erythroblastosis fetalis, the disease may be produced by any of the other blood
..... Click the link for more information. , is a hemolytic disease of newborns caused by an immune reaction between fetal red blood cells and maternal antibodies to them. Some hemolytic conditions, e.g., those in which red blood cells are fragile and rupture easily, are treated by removal of the spleen to slow cell breakdown or by administration of steroidssteroids,
class of lipids having a particular molecular ring structure called the cyclopentanoperhydro-phenanthrene ring system. Steroids differ from one another in the structure of various side chains and additional rings. Steroids are common in both plants and animals.
..... Click the link for more information. . Autoimmune hemolytic conditions result from splenomegaly. The spleen not only sequesters red blood cells, but produces antibodies against the body's red blood cells. This is a potentially lethal condition that occurs more often in women than men.

Hemolysis

(hematolysis, erythrocytolysis), the destruction of erythrocytes, accompanied by the release of hemoglobin into the surrounding medium.

Physiological hemolysis, a process that completes the 120-day life cycle of the erythrocyte, takes place continuously in man and animals. Under normal physiological conditions 0.8 percent of all the erythrocytes—usually the “aging” ones—undergo lysis. The final decomposition of these aging erythrocytes takes place primarily in the spleen. When the erythrocytes are decomposed bilirubin, one of the bile pigments, is formed from the liberated hemoglobin through a series of complex transformations; the extent of hemolysis can therefore be judged from the amount of bilirubin in the blood and bilirubin derivatives in the feces and urine. The iron liberated in the breakdown of hemoglobin is deposited in the reticuloendothelial cells of the liver and spleen. After complex transformations, this iron is bound to the beta globulin fraction of blood albumin and then takes part in the formation of new hemoglobin.

Disruption of the balance between the lytic agent and the inhibitor may lead to the predominance of blood destruction over blood formation—in other words, to pathological hemolysis. Pathological hemolysis occurs in hemolytic anemias and hemoglobinopathies. It may result from hemolytic poisons (such as certain bacterial toxins, lead, arsenic, nitrobenzene, and morel toxin), from the formation of autoimmune and isoerythrocytic antibodies following the transfusion of incompatible blood, from Rh conflict in the newborn, from the action of certain chemical agents and cold, and, in sensitive individuals, after taking certain drugs or inhaling some types of pollen. In pathological hemolysis, erythrocytes are destroyed in all cells of the reticuloendothelial system (for example, in the liver, bone marrow, or lymph nodes) and also possibly in the bloodstream. In this case most of the hemoglobin of the destroyed erythrocytes is bound to a specific protein (haptoglobin) while the excess passes through the renal filter into the urine (hemoglobinuria). The destruction of a large mass of erythrocytes at once, such as in hemolytic anemias, may be accompanied by a serious condition (hemolytic shock) which may result in death.

Hemolysis may occur in blood that has been stored for a long time, rendering it no longer suitable for ordinary transfusions.

A. M. POLIANSKAIA

hemolysis

[hē′mäl·ə·səs] (physiology) The lysis, or destruction, of erythrocytes with the release of hemoglobin.

hemolysis

[he-mol´ĭ-sis] rupture of erythrocytes with release of hemoglobin into the plasma. Some microbes form substances called hemolysins that have the specific action of destroying red blood cells; the beta-hemolytic streptococcus is an example. Intravenous administration of a hypotonic solution or plain distilled water will also destroy red blood cells by causing them to fill with fluid until their membranes rupture.
In a transfusion reaction or in erythroblastosis fetalis, incompatibility causes the red blood cells to clump together. The agglutinated cells become trapped in the smaller vessels and eventually disintegrate, releasing hemoglobin into the plasma. Kidney damage may result as the hemoglobin crystallizes and obstructs the renal tubules, producing renal shutdown and uremia.
Snake venoms and vegetable poisons such as mushrooms may also cause hemolysis. A great variety of chemical agents can lead to destruction of erythrocytes if there is exposure to a sufficiently high concentration of the substance. These chemical hemolytics include arsenic, lead, benzene, acetanilid, nitrites, and potassium chlorate.

he·mol·y·sis

(hē-mol'i-sis), Alteration, dissolution, or destruction of red blood cells in such a manner that hemoglobin is liberated into the medium in which the cells are suspended, for example, by specific complement-fixing antibodies, toxins, various chemical agents, tonicity, alteration of temperature. Synonym(s): erythrocytolysis, erythrolysis, hematolysis [hemo- + G. lysis, destruction]

hemolysis

(hĭ-mŏl′ĭ-sĭs, hē′mə-lī′sĭs)n. The destruction or dissolution of red blood cells, with subsequent release of hemoglobin.

he′mo·lyt′ic (hē′mə-lĭt′ĭk) adj.

transfusion reaction

Blood transfusion reaction, incompatibility reaction Transfusion medicine Any untoward response to the transfusion of non-self blood products, in particular RBCs, which evokes febrile reactions that are either minor–occurring in 1:40 transfusions and attributed to nonspecific leukocyte-derived pyrogens, or major–occurring in 1:3000 transfusions and caused by a true immune reaction, which is graded according to the presence of urticaria, itching, chills, fever and, if the reaction is intense, collapse, cyanosis, chest and/or back pain and diffuse hemorrhage Note: If any of above signs appear in a transfusion reaction, or if the temperature rises 1ºC, the transfusion must be stopped; most Pts survive if < 200 ml has been transfused in cases of red cell incompatibility-induced transfusion reaction; over 50% die when 500 ml or more has been transfused; TF mortality is ± 1.13/105 transfusions Clinical Flank pain, fever, chills, bloody urine, rash, hypotension, vertigo, fainting Transfusion reactions Immune, non-infectious transfusion reactions
• Allergic Urticaria with immediate hypersensitivity • Anaphylaxis Spontaneous anti-IgA antibody formation, occurs in ± 1:30 of Pts with immunoglobulin A deficiency, which affects 1:600 of the general population–total frequency: 1/30 X 1/600 = 1/18,000 • Antibodies to red cell antigens, eg antibodies to ABH, Ii, MNSs, P1, HLA • Serum sickness Antibodies to donor's immunoglobulins and proteins Non-immune, non-infectious transfusion reactions
• Air embolism A problem of historic interest that occurred when air vents were included in transfusion sets • Anticoagulant Citrate anticoagulant may cause tremors and EKG changes • Coagulation defects Depletion of factors VIII and V; this 'dilutional' effect requires massive transfusion of 10 + units before becoming significant • Cold blood In ultra-emergent situations, blood stored at 4º C may be tranfused prior to reaching body temperature at 37º C; warming a unit of blood from 4 to 37º C requires 30 kcal/L of energy, consumed as glucose; cold blood slows metabolism, exacerbates lactic acidosis, ↓ available calcium, ↑ hemoglobin's affinity for O₂ and causes K⁺ leakage, a major concern in cold hemoglobinuria • Hemolysis A phenomenon due to blood collection trauma, a clinically insignificant problem • Hyperammonemia and lactic acid Both molecules accumulate during packed red cell storage and when transfused, require hepatorenal clearance, of concern in Pts with hepatic or renal dysfunction, who should receive the freshest units possible • Hyperkalemia Hemolysis causes an ↑ of 1 mmol/L/day of potassium in a unit of stored blood, of concern in Pts with poor renal function, potentially causing arrhythmia • Iron overload Each unit of packed RBCs has 250 mg iron, potentially causing hemosiderosis in multi-transfused Pts Microaggregates Sludged debris in the pulmonary vasculature causing ARDS may be removed with micropore filters Pseudoreaction Transfusion reaction mimics, eg anxiety, anaphylaxis related to a drug being administered at the same time as the transfusion Infections transmitted by blood transfusion • Viruses B19, CMV, EBV, HAV, HBV, HCV, HDV, HEV, Creutzfeldt-Jakob disease, Colorado tick fever, tropical viruses–eg Rift Valley fever, Ebola, Lassa, dengue, HHV 6, HIV-1, HIV-2, HTLV-I, HTLV-II • Bacteria Transmission of bacterial infections from an infected donor is uncommon and includes brucellosis and syphilis in older reports; more recent reports include Lyme disease and Yersinia enterocolitica Note: Although virtually any bacteria could in theory be transmitted in blood, the usual cause is contamination during processing rather than transmission from an infected donor • Parasites Babesiosis, Leishmania donovani, L tropica, malaria, microfilariasis–Brugia malayi, Loa loa, Mansonella perstans, Mansonella ozzardi, Toxoplasma gondii, Trypanosoma cruzi

hemoglobinuria

Hematology The presence of Hb in the urine which, if of sufficient quantity, colors urine, the intensity of which directly correlates with the quantity of Hb. See Paroxysmal cold hemoglobinuria, Paroxysmal nocturnal hemoglobinuria. hemolysis Destruction or lysis of RBCs Hemolysis Intracorpuscular hemolysis • Membrane defects, eg hereditary elliptocytosis, spherocytosis, stomatocytosis and paroxysmal nocturnal hemoglobinuria • Metabolic defects, eg G6PD, pyruvate kinase deficiency • Abnormal Hbs see Hemoglobin. Extracorpuscular hemolysis 1º immune reactions, eg autoimmune hemolytic anemia 2º immune reactions, due to • Infections, eg Bartonella, Clostridia, malaria, sepsis • Neoplasia, eg lymphoma, leukemias • Drug reactions due to the 'Innocent bystander' phenomenon (drug-antibody complex activates complement, causing intravascular hemolysis, eg quinidine), hapten-mediated —a protein-bound drug attaches to the red cell membrane, eliciting an immune response when the hapten-protein complex is recognized as foreign, evoking an immune response, eg penicillin acting as a hapten • Induction of autoimmunity by RBC antigen alterations, eg Rh antigen Physical, eg thermal, concentrated glycerol due to inadequate washing of frozen blood, bladder irrigation, cardiac valves Extravascular Less severe, IgG-mediated and does not activate complement, eg Rh, Kell, Duffy Laboratory ↓ haptoglobin, ↓ T_1/2 of circulating RBCs, ↑ indirect BR as liver capacity to conjugate BR–ergo direct BR is overwhelmed by massive hemolysis, ↑ LDH, Hb in blood and urine, hemosiderinuria, MetHb and metalbumin, ↑ urobilinogen in urine and feces, ↑ in acid phosphatase, K+, and prostatic acid phosphatase Clin Chem 1992; 38:575; peripheral smears demonstrate anisocytosis, polychromatophilia, nucleated RBCs, basophilic stippling; immune hemolysis is suggested by spherocytes NEJM 2000; 342:722cpc Intravascular More severe, IgM-mediated and requires complement activation, eg ABO blood groups Laboratory ↑ free Hb Note: Clinically significant hemolysis is usually detected by hemagglutination, less commonly by hemolysis per se, which detects anti-P,
-P₁, -PP₁Pk, -Jka, -Lea, occasionally also anti-Leb and -Vel

he·mol·y·sis

(hē-mol'i-sis) Alteration, dissolution, or destruction of red blood cells in such a manner that hemoglobin is liberated into the medium in which the cells are suspended.
Synonym(s): erythrocytolysis, erythrolysis, hematolysis, haemolysis. [hemo- + G. lysis, destruction]

Hemolysis

The process of breaking down of red blood cells. As the cells are destroyed, hemoglobin, the component of red blood cells which carries the oxygen, is liberated.Mentioned in: Coombs' Tests, Glucose-6-Phosphate Dehydrogenase Deficiency, Hemolytic Anemia, Hepatitis, Alcoholic, Jaundice, Physical Allergy

hemolysis

he·mol·y·sis

he•mol•y•sis

hemolysis, haemolysis

hemolysis

hemolysis

Hemolysis

hemolysis

hemolysis

hemolysis

he·mol·y·sis

hemolysis

transfusion reaction

hemoglobinuria

he·mol·y·sis

Hemolysis

he·mol·y·sis

hemolysis

Synonyms for hemolysis

noun lysis of erythrocytes with the release of hemoglobin

Synonyms

Related Words