Toxic granulation refers to dark coarse granules found in granulocytes, particularly neutrophils, in patients with inflammatory conditions. [1]
Toxic granulation refers to dark coarse granules found in granulocytes, particularly neutrophils, in patients with inflammatory conditions. [1]
Along with Döhle bodies and toxic vacuolation, which are two other findings in the cytoplasm of granulocytes, toxic granulation is a peripheral blood film finding suggestive of an inflammatory process. [1] Toxic granulation is often found in patients with bacterial infection and sepsis, [1] [2] although the finding is nonspecific. [3] Patients being treated with chemotherapy [3] or granulocyte colony stimulating factor, a cytokine drug, may also exhibit toxic granulation. [2]
Toxic granules are mainly composed of peroxidase and acid hydrolase enzymes, [3] and are similar in composition to the primary granules found in immature granulocytic cells like promyelocytes. [4] [5] Although normal, mature neutrophils do contain some primary granules, the granules are difficult to identify by light microscopy because they lose their dark blue colour as the cells mature. Toxic granulation thus represents abnormal maturation of neutrophils. [6]
Patients with the inherited condition Alder-Reilly anomaly exhibit very large, darkly staining granules in their neutrophils, which can be confused with toxic granulation. [2] [7]
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.
Neutropenia is an abnormally low concentration of neutrophils in the blood. Neutrophils make up the majority of circulating white blood cells and serve as the primary defense against infections by destroying bacteria, bacterial fragments and immunoglobulin-bound viruses in the blood. People with neutropenia are more susceptible to bacterial infections and, without prompt medical attention, the condition may become life-threatening.
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.
Neutrophils are a type of phagocytic white blood cell and part of innate immunity. More specifically, they form the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. Their functions vary in different animals. They are also known as neutrocytes, heterophils or polymorphonuclear leukocytes.
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include T cells, B cells, and innate lymphoid cells, of which natural killer cells are an important subtype. They are the main type of cell found in lymph, which prompted the name "lymphocyte". Lymphocytes make up between 18% and 42% of circulating white blood cells.
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.
Granulocytes are cells in the innate immune system characterized by the presence of specific granules in their cytoplasm. Such granules distinguish them from the various agranulocytes. All myeloblastic granulocytes are polymorphonuclear, that is, they have varying shapes (morphology) of the nucleus ; and are referred to as polymorphonuclear leukocytes. In common terms, polymorphonuclear granulocyte refers specifically to "neutrophil granulocytes", the most abundant of the granulocytes; the other types have varying morphology. Granulocytes are produced via granulopoiesis in the bone marrow.
Leukocytosis is a condition in which the white cell (leukocyte) count is above the normal range in the blood. It is frequently a sign of an inflammatory response, most commonly the result of infection, but may also occur following certain parasitic infections or bone tumors as well as leukemia. It may also occur after strenuous exercise, convulsions such as epilepsy, emotional stress, pregnancy and labor, anesthesia, as a side effect of medication, and epinephrine administration. There are five principal types of leukocytosis:
A megakaryoblast is a precursor cell to a promegakaryocyte. During thrombopoiesis, the promegakaryocyte matures into the form of a megakaryocyte. From the megakaryocyte, platelets are formed. The megakaryoblast is the beginning of the thrombocytic series or platelet forming series.
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.
Granulopoiesis is a part of haematopoiesis, that leads to the production of granulocytes. A granulocyte, also referred to as a polymorphonuclear leukocyte (PMN), is a type of white blood cell that has multi lobed nuclei, usually containing three lobes, and has a significant amount of cytoplasmic granules within the cell. Granulopoiesis takes place in the bone marrow. It leads to the production of three types of mature granulocytes: neutrophils, eosinophils and basophils.
Pelger–Huët anomaly is a blood laminopathy associated with the lamin B receptor, wherein several types of white blood cells have nuclei with unusual shape and unusual structure.
Basophilia is the condition of having greater than 200 basophils/μL in the venous blood. Basophils are the least numerous of the myelogenous cells, and it is rare for their numbers to be abnormally high without changes to other blood components. Rather, basophilia is most often coupled with other white blood cell conditions such as eosinophilia, high levels of eosinophils in the blood. Basophils are easily identifiable by a blue coloration of the granules within each cell, marking them as granulocytes, in addition to segmented nuclei.
Neutrophil hypersegmentation can be defined as the presence of neutrophils whose nuclei have six or more lobes or the presence of more than 3% of neutrophils with at least five nuclear lobes. This is a clinical laboratory finding. It is visualized by drawing blood from a patient and viewing the blood smeared on a slide under a microscope. Normal neutrophils are uniform in size, with an apparent diameter of about 13 μm in a film. When stained, neutrophils have a segmented nucleus and pink/orange cytoplasm under light microscope. The majority of neutrophils have three nuclear segments (lobes) connected by tapering chromatin strands. A small percentage have four lobes, and occasionally five lobes may be seen. Up to 8% of circulating neutrophils are unsegmented.
In hematology, myelopoiesis in the broadest sense of the term is the production of bone marrow and of all cells that arise from it, namely, all blood cells. In a narrower sense, myelopoiesis also refers specifically to the regulated formation of myeloid leukocytes (myelocytes), including eosinophilic granulocytes, basophilic granulocytes, neutrophilic granulocytes, and monocytes.
White blood cells, also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. White blood cells are generally larger than red blood cells. They include three main subtypes: granulocytes, lymphocytes and monocytes.
Toxic vacuolation, also known as toxic vacuolization, is the formation of vacuoles in the cytoplasm of neutrophils in response to severe infections or inflammatory conditions.
A white blood cell differential is a medical laboratory test that provides information about the types and amounts of white blood cells in a person's blood. The test, which is usually ordered as part of a complete blood count (CBC), measures the amounts of the five normal white blood cell types – neutrophils, lymphocytes, monocytes, eosinophils and basophils – as well as abnormal cell types if they are present. These results are reported as percentages and absolute values, and compared against reference ranges to determine whether the values are normal, low, or high. Changes in the amounts of white blood cells can aid in the diagnosis of many health conditions, including viral, bacterial, and parasitic infections and blood disorders such as leukemia.
Alder–Reilly anomaly, or Alder anomaly, is an inherited abnormality of white blood cells associated with mucopolysaccharidosis. When blood smears and bone marrow preparations from patients with Alder–Reilly anomaly are stained and examined microscopically, large, coarse granules may be seen in their neutrophils, monocytes, and lymphocytes. The condition may be mistaken for toxic granulation, a type of abnormal granulation in neutrophils that occurs transiently in inflammatory conditions.
A granulocyte transfusion is a medical procedure in which granulocytes are infused into a person's blood. Granulocyte transfusions were historically used to prevent and treat infections in people with neutropenia, but the practice declined in popularity in the 1980s. Interest in the procedure increased in the 1990s due to the development of more effective methods for harvesting granulocytes and a growing population of people with severe neutropenia from chemotherapy. However, the treatment's efficacy remains poorly understood and its use is controversial.