This article needs more reliable medical references for verification or relies too heavily on primary sources .(December 2015) |
Autoimmune neutropenia | |
---|---|
Other names | Autoimmune neutropenia of infancy and primary autoimmune neutropenia |
Pronunciation |
|
Specialty | Hematology |
Symptoms | Weak immune system, mouth ulcers, sore throat, lethargy, high fever and chills |
Usual onset | Present from birth |
Duration | Disappears or weakens by age three |
Causes | Autoimmune abnormality |
Diagnostic method | Blood tests |
Treatment | Granulocyte colony-stimulating factors (G-CSF) |
Medication | Corticosteroids and antibiotics |
Prognosis | Disappears or weakens by age three |
Frequency | In the U.s: 1 per 100,000 newborns |
Deaths | None recorded |
Autoimmune neutropenia (AIN) is a form of neutropenia which is most common in infants and young children [1] where the body identifies the neutrophils as enemies and makes antibodies to destroy them.
Primary autoimmune neutropenia, another name for autoimmune neutropenia, is an autoimmune disease first reported in 1975 that primarily occurs in infancy. [2] In autoimmune neutropenia, the immune system produces autoantibodies directed against the neutrophilic protein antigens in white blood cells known as granulocytic neutrophils, granulocytes, segmented neutrophils, segs, polysegmented neutrophils, or polys. These antibodies, IgG antibodies, destroy granulocytic neutrophils. [3] Consequently, patients with autoimmune neutropenia have low levels of granulocytic neutrophilic white blood cells causing a condition of neutropenia. Neutropenia causes an increased risk of infection from organisms that the body could normally fight easily.
Primary autoimmune neutropenia has been reported as early as the second month of life although most cases are diagnosed in children between 5 and 15 months of age. [3] Girls have a slightly higher risk of developing AIN than boys as well as do people of Caucasian background. [4] In neutropenia discovered at birth or shortly after birth, a diagnosis of allo-immune neutropenia (from maternal white blood cell antibodies passively transferred to the infant) is more likely.
In infants neutropenia is defined by absolute neutrophil counts less than 1000/uL. After the first year of life neutropenia is defined by absolute counts less than 1500/uL. Neutropenia may be primary in which it is the only blood abnormality seen. In secondary neutropenia, other primary conditions occur, including other autoimmune diseases, infections, and cancers. Neutropenia is considered chronic when it persists for more than 6 months.
Neutropenia, which may be discovered on routine blood tests, typically causes benign infections even when the condition is severe. Ear infections (otitis media) are the most common infection seen in autoimmune neutropenia and typically infection responds to antibiotic treatment alone. Infections associated with primary AIN are usually mild and limited, including skin infections such as impetigo, gastroenteritis, upper respiratory tract infections, and ear infections. Rarely, cellulitis and abscesses may occur. [5] Studies of children studied for up to six years showed that most cases of autoimmune neutropenia resolved spontaneously after a median of 17 months. In 95 percent of patients, neutropenia persisted for 7 to 24 months. [1]
The diagnosis of autoimmune neutropenia is based on blood tests demonstrating neutropenia and the presence of granulocyte-specific antibodies. In some cases, tests for granulocyte-specific antibodies must be repeated several times before a positive result is seen. Bone marrow aspiration, if performed, is typically normal or it can show increased cell production with a variably diminished number of segmented granulocytes. [2]
An association with prior parvovirus B19 has been made, but this hasn’t been confirmed. [1]
Treatment consists of corticosteroids to reduce autoantibody production and antibiotics to prevent infection.
Granulocyte colony-stimulating factor (G-CSF) is recommended to temporarily increase neutrophil counts in patients with absolute neutrophil counts (ANC) of less than 0.5 x 109/l and recurrent fever or infections. [6] [7]
In cases of severe infection or the need for surgery, intravenous immunoglobulin therapy may be used. [8]
This form of neutropenia disappears in two to three years of a child's life in 95% of cases. [3]
The use of prophylactic antibiotics has been successfully demonstrated to reduce infection incidence without causing adverse effects among the 5% of children whose condition does not resolve itself. [9] [10]
Agranulocytosis, also known as agranulosis or granulopenia, is an acute condition involving a severe and dangerous lowered white blood cell count and thus causing neutropenia in the circulating blood. It is a severe lack of one major class of infection-fighting white blood cells. People with this condition are at very high risk of serious infections due to their suppressed immune system.
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.
Immune thrombocytopenic purpura (ITP), also known as idiopathic thrombocytopenic purpura or immune thrombocytopenia, is an autoimmune primary disorder of hemostasis characterized by a low platelet count in the absence of other causes. ITP often results in an increased risk of bleeding from mucosal surfaces or the skin. Depending on which age group is affected, ITP causes two distinct clinical syndromes: an acute form observed in children and a chronic form in adults. Acute ITP often follows a viral infection and is typically self-limited, while the more chronic form does not yet have a specific identified cause. Nevertheless, the pathogenesis of ITP is similar in both syndromes involving antibodies against various platelet surface antigens such as glycoproteins.
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.
In medicine, granulocytosis is the presence of an increased number of granulocytes in the peripheral blood. Often, the word refers to an increased neutrophil granulocyte count (neutrophilia), but granulocytosis formally refers to the combination of neutrophilia, eosinophilia, and basophilia. Leukocytosis refers to an increase in the number of all white blood cells.
Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that affect the patient's immune system. Examples of these extrinsic factors include HIV infection and environmental factors, such as nutrition. Immunocompromisation may also be due to genetic diseases/flaws such as SCID.
Leukopenia is a decrease in the number of leukocytes (WBC). Found in the blood, they are the white blood cells, and are the body's primary defense against an infection. Thus the condition of leukopenia places individuals at increased risk of infection.
Pemphigus is a rare group of blistering autoimmune diseases that affect the skin and mucous membranes. The name is derived from the Greek root pemphix, meaning "blister".
Absolute neutrophil count (ANC) is a measure of the number of neutrophil granulocytes present in the blood. Neutrophils are a type of white blood cell that fights against infection.
Evans syndrome is an autoimmune disease in which an individual's immune system attacks their own red blood cells and platelets, the syndrome can include immune neutropenia. These immune cytopenias may occur simultaneously or sequentially.
Cyclic neutropenia (CyN) is a rare hematologic disorder and form of congenital neutropenia that tends to occur approximately every three weeks and lasting for few days at a time due to changing rates of neutrophil production by the bone marrow. It causes a temporary condition with a low absolute neutrophil count and because the neutrophils make up the majority of circulating white blood cells it places the body at severe risk of inflammation and infection. In comparison to severe congenital neutropenia, it responds well to treatment with granulocyte colony-stimulating factor (filgrastim), which increases the neutrophil count, shortens the cycle length, as well decreases the severity and frequency of infections.
Severe congenital neutropenia (SCN), also often known as Kostmann syndrome or disease, is a group of rare disorders that affect myelopoiesis, causing a congenital form of neutropenia, usually without other physical malformations. SCN manifests in infancy with life-threatening bacterial infections. It causes severe pyogenic infections. It can be caused by autosomal dominant inheritance of the ELANE gene, autosomal recessive inheritance of the HAX1 gene. There is an increased risk of leukemia and myelodysplastic cancers.
Autoimmune hemolytic anemia (AIHA) is an autoimmune disorder which occurs when antibodies directed against the person's own red blood cells (RBCs) cause them to burst (lyse), leading to an insufficient number of oxygen-carrying red blood cells in circulation (anemia). The lifetime of the RBCs is reduced from the normal 100–120 days to just a few days in serious cases. The intracellular components of the RBCs are released into the circulating blood and into tissues, leading to some of the characteristic symptoms of this condition. The antibodies are usually directed against high-incidence antigens, therefore they also commonly act on allogenic RBCs. AIHA is a relatively rare condition, with an incidence of 5–10 cases per 1 million persons per year in the warm-antibody type and 0.45 to 1.9 cases per 1 million persons per year in the cold-antibody type. Autoimmune hemolysis might be a precursor of later onset systemic lupus erythematosus.
Paroxysmal cold hemoglobinuria (PCH) or Donath–Landsteiner hemolytic anemia (DLHA) is an autoimmune hemolytic anemia featured by complement-mediated intravascular hemolysis after cold exposure. It can present as an acute non-recurrent postinfectious event in children, or chronic relapsing episodes in adults with hematological malignancies or tertiary syphilis. Described by Julius Donath (1870–1950) and Karl Landsteiner (1868–1943) in 1904, PCH is one of the first clinical entities recognized as an autoimmune disorder.
Cold agglutinin disease (CAD) is a rare autoimmune disease characterized by the presence of high concentrations of circulating cold sensitive antibodies, usually IgM and autoantibodies that are also active at temperatures below 30 °C (86 °F), directed against red blood cells, causing them to agglutinate and undergo lysis. It is a form of autoimmune hemolytic anemia, specifically one in which antibodies bind red blood cells only at low body temperatures, typically 28–31 °C.
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 include three main subtypes: granulocytes, lymphocytes and monocytes.
Neutrophil-specific granule deficiency is a rare congenital immunodeficiency characterized by an increased risk for pyogenic infections due to defective production of specific granules and gelatinase granules in patient neutrophils.
Cold autoimmune hemolytic anemia caused by cold-reacting antibodies. Autoantibodies that bind to the erythrocyte membrane leading to premature erythrocyte destruction (hemolysis) characterize autoimmune hemolytic anemia.
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.
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.