A blood cell is a cell produced through hematopoiesis and found mainly in the blood. Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Together, these three kinds of blood cells add up to a total 45% of the blood tissue by volume, with the remaining 55% of the volume composed of plasma, the liquid component of blood.
Hemoglobinopathy is the medical term for a group of inherited blood disorders involving the hemoglobin, the protein of red blood cells. They are single-gene disorders and, in most cases, they are inherited as autosomal co-dominant traits.
Anemia or anaemia is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin available for oxygen transport, or abnormalities in hemoglobin that impair its function.
A myelodysplastic syndrome (MDS) is one of a group of cancers in which blood cells in the bone marrow do not mature, and as a result, do not develop into healthy blood cells. Early on, no symptoms typically are seen. Later, symptoms may include fatigue, shortness of breath, bleeding disorders, anemia, or frequent infections. Some types may develop into acute myeloid leukemia.
In hematology, reticulocytes are immature red blood cells (RBCs). In the process of erythropoiesis, reticulocytes develop and mature in the bone marrow and then circulate for about a day in the blood stream before developing into mature red blood cells. Like mature red blood cells, in mammals, reticulocytes do not have a cell nucleus. They are called reticulocytes because of a reticular (mesh-like) network of ribosomal RNA that becomes visible under a microscope with certain stains such as new methylene blue and Romanowsky stain.
Erythropoiesis is the process which produces red blood cells (erythrocytes), which is the development from erythropoietic stem cell to mature red blood cell.
Reticulocytosis is a laboratory finding in which the number of reticulocytes in the bloodstream is elevated. Reticulocytes account for approximately 0.5% to 2.5% of the total red blood cells in healthy adults and 2% to 6% in infants, but in reticulocytosis, this percentage rises. Reticulocytes are produced in the bone marrow and then released into the bloodstream, where they mature into fully developed red blood cells between 1-2 days. Reticulocytosis often reflects the body’s response to conditions rather than an independent disease process and can arise from a variety of causes such as blood loss or anemia.
The myeloblast is a unipotent stem cell which differentiates into the effectors of the granulocyte series. It is found in the bone marrow. Stimulation of myeloblasts by G-CSF and other cytokines triggers maturation, differentiation, proliferation and cell survival.
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.
A proerythroblast is a precursor cell to the normoblast, as the earliest of four stages in its development.
Extramedullary hematopoiesis refers to hematopoiesis occurring outside of the medulla of the bone. It can be physiologic or pathologic.
GATA-binding factor 1 or GATA-1 is the founding member of the GATA family of transcription factors. This protein is widely expressed throughout vertebrate species. In humans and mice, it is encoded by the GATA1 and Gata1 genes, respectively. These genes are located on the X chromosome in both species.
Reticulocytopenia is the medical term for an abnormal decrease in circulating red blood cell precursors (reticulocytes) that can lead to anemia due to resulting low red blood cell (erythrocyte) production. Reticulocytopenia may be an isolated finding or it may not be associated with abnormalities in other hematopoietic cell lineages such as those that produce white blood cells (leukocytes) or platelets (thrombocytes), a decrease in all three of these lineages is referred to as pancytopenia.
Myelophthisic anemia is a severe type of anemia found in some people with diseases that affect the bone marrow. Myelophthisis refers to the displacement of hemopoietic bone-marrow tissue by fibrosis, tumors, or granulomas. The word comes from the roots myelo-, which refers to bone marrow, and phthisis, shrinkage or atrophy.
A promyelocyte is a granulocyte precursor, developing from the myeloblast and developing into the myelocyte. Promyelocytes measure 12–20 microns in diameter. The nucleus of a promyelocyte is approximately the same size as a myeloblast but their cytoplasm is much more abundant. They also have less prominent nucleoli than myeloblasts and their chromatin is more coarse and clumped. The cytoplasm is basophilic and contains primary red/purple granules.
Normocytic anemia is a type of anemia and is a common issue that occurs for men and women typically over 85 years old. Its prevalence increases with age, reaching 44 percent in men older than 85 years. The most common type of normocytic anemia is anemia of chronic disease.
Congenital hemolytic anemia (CHA) is a diverse group of rare hereditary conditions marked by decreased life expectancy and premature removal of erythrocytes from blood flow. Defects in erythrocyte membrane proteins and red cell enzyme metabolism, as well as changes at the level of erythrocyte precursors, lead to impaired bone marrow erythropoiesis. CHA is distinguished by variable anemia, chronic extravascular hemolysis, decreased erythrocyte life span, splenomegaly, jaundice, biliary lithiasis, and iron overload. Immune-mediated mechanisms may play a role in the pathogenesis of these uncommon diseases, despite the paucity of data regarding the immune system's involvement in CHAs.
Polychromasia is a disorder where there is an abnormally high number of immature red blood cells found in the bloodstream as a result of being prematurely released from the bone marrow during blood formation These cells are often shades of grayish-blue. Polychromasia is usually a sign of bone marrow stress as well as immature red blood cells. 3 types are recognized, with types 1 and 2 being referred to as 'young red blood cells' and type 3 as 'old red blood cells'. Giemsa stain is used to distinguish all three types of blood smears. The young cells will generally stain gray or blue in the cytoplasm. These young red blood cells are commonly called reticulocytes. All polychromatophilic cells are reticulocytes, however, not all reticulocytes are polychromatophilic. In the old blood cells, the cytoplasm either stains a light orange or does not stain at all.
Congenital dyserythropoietic anemia type IV has been described with typical morphologic features of CDA II but a negative acidified-serum test.
