Hemolysis or haemolysis, also known by several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid. Hemolysis may occur in vivo or in vitro.
Anemia or anaemia is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. The name is derived from Ancient Greek: ἀναιμία anaimia, meaning 'lack of blood', from ἀν- an-, 'not' and αἷμα haima, 'blood'. When anemia comes on slowly, the symptoms are often vague, such as tiredness, weakness, shortness of breath, headaches, and a reduced ability to exercise. When anemia is acute, symptoms may include confusion, feeling like one is going to pass out, loss of consciousness, and increased thirst. Anemia must be significant before a person becomes noticeably pale. Symptoms of anemia depend on how quickly hemoglobin decreases. Additional symptoms may occur depending on the underlying cause. Preoperative anemia can increase the risk of needing a blood transfusion following surgery. Anemia can be temporary or long term and can range from mild to severe.
A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide information about the cells in a person's blood. The CBC indicates the counts of white blood cells, red blood cells and platelets, the concentration of hemoglobin, and the hematocrit. The red blood cell indices, which indicate the average size and hemoglobin content of red blood cells, are also reported, and a white blood cell differential, which counts the different types of white blood cells, may be included.
A blood smear, peripheral blood smear or blood film is a thin layer of blood smeared on a glass microscope slide and then stained in such a way as to allow the various blood cells to be examined microscopically. Blood smears are examined in the investigation of hematological (blood) disorders and are routinely employed to look for blood parasites, such as those of malaria and filariasis.
Hemolytic anemia or haemolytic anaemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells (RBCs), either in the blood vessels or elsewhere in the human body (extravascular). This most commonly occurs within the spleen, but also can occur in the reticuloendothelial system or mechanically. Hemolytic anemia accounts for 5% of all existing anemias. It has numerous possible consequences, ranging from general symptoms to life-threatening systemic effects. The general classification of hemolytic anemia is either intrinsic or extrinsic. Treatment depends on the type and cause of the hemolytic anemia.
Pyruvate kinase deficiency is an inherited metabolic disorder of the enzyme pyruvate kinase which affects the survival of red blood cells. Both autosomal dominant and recessive inheritance have been observed with the disorder; classically, and more commonly, the inheritance is autosomal recessive. Pyruvate kinase deficiency is the second most common cause of enzyme-deficient hemolytic anemia, following G6PD deficiency.
Microcytic anaemia is any of several types of anemia characterized by smaller than normal red blood cells. The normal mean corpuscular volume is approximately 80–100 fL. When the MCV is <80 fL, the red cells are described as microcytic and when >100 fL, macrocytic. The MCV is the average red blood cell size.
Sideroblastic anemia, or sideroachrestic anemia, is a form of anemia in which the bone marrow produces ringed sideroblasts rather than healthy red blood cells (erythrocytes). In sideroblastic anemia, the body has iron available but cannot incorporate it into hemoglobin, which red blood cells need in order to transport oxygen efficiently. The disorder may be caused either by a genetic disorder or indirectly as part of myelodysplastic syndrome, which can develop into hematological malignancies.
Maxwell Myer Wintrobe was an Austrian-born American physician who was a 20th-century authority in the medical field of hematology. His 1942 textbook on hematology, Clinical Hematology, was the first dedicated work in the field and he contributed to the diagnostic approach of anemia and copper metabolism, amongst many other achievements.
Hemoglobin electrophoresis is a blood test that can detect different types of hemoglobin. The test can detect hemoglobin S, the form associated with sickle cell disease, as well as other abnormal types of hemoglobin, such as hemoglobin C. It can also be used to investigate thalassemias, which are disorders caused by defective hemoglobin production.
Alpha-thalassemia is a form of thalassemia involving the genes HBA1 and HBA2. Thalassemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, the molecule that carries oxygen in the blood. Normal hemoglobin consists of two alpha chains and two beta chains; in alpha-thalassemia, there is a quantitative decrease in the amount of alpha chains, resulting in fewer normal hemoglobin molecules. Furthermore, alpha-thalassemia leads to the production of unstable beta globin molecules which cause increased red blood cell destruction. The degree of impairment is based on which clinical phenotype is present.
5′-Nucleotidase is an enzyme which catalyzes the phosphorylytic cleavage of 5′-nucleotides. Although originally found in snake venom, the activity of 5'nucleotidase has been described for bacteria and plant cells, and is widely distributed in vertebrate tissue. In mammalian cells the enzyme is predominantly located in the plasma membrane and its primary role is in the conversion of extracellular nucleotides, which are generally impermeable, to the corresponding nucleoside which can readily enter most cells. Consequently, the enzyme plays a key role in the metabolism of nucleotides.
Cytosolic 5'-nucleotidase 3 (NTC53), also known as cytosolic 5'-nucleotidase 3A, pyrimidine 5’-nucleotidase, and p56, is an enzyme that in humans is encoded by the NT5C3, or NT5C3A, gene on chromosome 7.
Pappenheimer bodies are abnormal basophilic granules of iron found inside red blood cells on routine blood stain. They are a type of inclusion body composed of ferritin aggregates, or mitochondria or phagosomes containing aggregated ferritin. They appear as dense, blue-purple granules within the red blood cell and there are usually only one or two, located in the cell periphery. They stain on a Romanowsky stain because clumps of ribosomes are co‐precipitated with the iron‐containing organelles.
Congenital hemolytic anemia refers to hemolytic anemia which is primarily due to congenital disorders.
A degmacyte or bite cell is an abnormally shaped mature red blood cell with one or more semicircular portions removed from the cell margin, known as "bites". These "bites" result from the mechanical removal of denatured hemoglobin during splenic filtration as red cells attempt to migrate through endothelial slits from splenic cords into the splenic sinuses. Bite cells are known to be a result from processes of oxidative hemolysis, such as Glucose-6-phosphate dehydrogenase deficiency, in which uncontrolled oxidative stress causes hemoglobin to denature and form Heinz bodies. Bite cells can contain more than one "bite." The "bites" in degmacytes are smaller than the missing red blood cell fragments seen in schistocytes.
Erythrocyte fragility refers to the propensity of erythrocytes to hemolyse (rupture) under stress. It can be thought of as the degree or proportion of hemolysis that occurs when a sample of red blood cells are subjected to stress. Depending on the application as well as the kind of fragility involved, the amount of stress applied and/or the significance of the resultant hemolysis may vary.
A nucleated red blood cell (NRBC), also known by several other names, is a red blood cell that contains a cell nucleus. Almost all vertebrate organisms have hemoglobin-containing cells in their blood, and with the exception of mammals, all of these red blood cells are nucleated. In mammals, NRBCs occur in normal development as precursors to mature red blood cells in erythropoiesis, the process by which the body produces red blood cells. NRBCs are normally found in the bone marrow of humans of all ages and in the blood of fetuses and newborn infants. After infancy, RBCs normally contain a nucleus only during the very early stages of the cell's life, and the nucleus is ejected as a normal part of cellular differentiation before the cell is released into the bloodstream. Thus, if NRBCs are identified on an adult's complete blood count or peripheral blood smear, it suggests that there is a very high demand for the bone marrow to produce RBCs, and immature RBCs are being released into circulation. Possible pathologic causes include anemia, myelofibrosis, thalassemia, miliary tuberculosis, cancers involving bone marrow, and in chronic hypoxemia.
Phaedon Fessas (1922-2015) was a Greek Professor of Medicine at the Medical School of Athens University. He was Director of the 1st Department of Internal Medicine at the Laikon Hospital in Athens (1969-1989), where he established a very strong Hematology Division, his particular subspecialty. Professor Fessas was a clinician, teacher and researcher. His main research interest was thalassemia.
