Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
The vast majority of those with hereditary elliptocytosis require no treatment whatsoever. They have a mildly increased risk of developing gallstones, which is treated surgically with a cholecystectomy if pain becomes problematic. This risk is relative to the severity of the disease.
Folate helps to reduce the extent of haemolysis in those with significant haemolysis due to hereditary elliptocytosis.
Because the spleen breaks down old and worn-out blood cells, those individuals with more severe forms of hereditary elliptocytosis can have splenomegaly. Symptoms of splenomegaly can include:
- Vague, poorly localised abdominal pain
- Fatigue and dyspnoea
- Growth failure
- Leg ulcers
- Gallstones.
Removal of the spleen (splenectomy) is effective in reducing the severity of these complications, but is associated with an increased risk of overwhelming bacterial septicaemia, and is only performed on those with significant complications. Because many neonates with severe elliptocytosis progress to have only a mild disease, and because this age group is particularly susceptible to pneumococcal infections, a splenectomy is only performed on those under 5 years old when it is absolutely necessary.
Hereditary elliptocytosis, also known as ovalocytosis, is an inherited blood disorder in which an abnormally large number of the patient's erythrocytes (i.e. red blood cells) are elliptical rather than the typical disc shape. Such morphologically distinctive erythrocytes are sometimes referred to as elliptocytes or ovalocytes. It is one of many red-cell membrane defects. In its severe forms, this disorder predisposes to haemolytic anaemia. Although pathological in humans, elliptocytosis is normal in camelids.
Hereditary spherocytosis (also known as Minkowski–Chauffard syndrome) abnormality of erythrocytes. The disorder is caused by mutations in genes relating to membrane proteins that allow for the erythrocytes to change shape. The abnormal erythrocytes are sphere-shaped (spherocytosis) rather than the normal biconcave disk shaped. Dysfunctional membrane proteins interfere with the cell's ability to be flexible to travel from the arteries to the smaller capillaries. This difference in shape also makes the red blood cells more prone to rupture. Cells with these dysfunctional proteins are taken for degradation at the spleen. This shortage of erythrocytes results in hemolytic anemia.
It was first described in 1871 and is the most common cause of inherited hemolysis in Europe and North America within the Caucasian population, with an incidence of 1 in 5000 births. The clinical severity of HS varies from symptom-free
carrier to severe haemolysis because the disorder exhibits incomplete penetrance in its expression.
Symptoms include anemia, jaundice, splenomegaly, and fatigue. On a blood smear, Howell-Jolly bodies may be seen within red blood cells. Primary treatment for patients with symptomatic HS has been total splenectomy, which eliminates the hemolytic process, allowing normal hemoglobin, reticulocyte and bilirubin levels.
As in non-hereditary spherocytosis, the spleen destroys the spherocytes. This process of red blood cells rupturing directly results in varying degrees of anemia (causing a pale appearance and fatigue), high levels of bilirubin in the blood (causing jaundice), and splenomegaly.
Acute cases can threaten to cause hypoxia through anemia and acute kernicterus through high blood levels of bilirubin, particularly in newborns. Most cases can be detected soon after birth. An adult with this disease should have their children tested, although the presence of the disease in children is usually noticed soon after birth. Occasionally, the disease will go unnoticed until the child is about 4 or 5 years of age. A person may also be a carrier of the disease and show no signs or symptoms of the disease. Other symptoms may include abdominal pain that could lead to the removal of the spleen and/or gallbladder.
Chronic symptoms include anemia, increased blood viscosity, and splenomegaly, and some symptoms are still unknown at this stage. Furthermore, the detritus of the broken-down blood cells – unconjugated or indirect bilirubin – accumulates in the gallbladder, and can cause pigmented gallstones to develop. In chronic patients, an infection or other illness can cause an increase in the destruction of red blood cells, resulting in the appearance of acute symptoms, a "hemolytic crisis". Spherocytosis patients who are heterozygous for a hemochromatosis gene may suffer from iron overload despite the hemochromatosis genes being recessive.
In a peripheral blood smear, the red blood cells will "appear" abnormally small and lack the central pale area that is present in normal red blood cells. These changes are also seen in non-hereditary spherocytosis, but they are typically more pronounced in hereditary spherocytosis. The number of immature red blood cells (reticulocyte count) will be elevated. An increase in the mean corpuscular hemoglobin concentration is also consistent with hereditary spherocytosis.
Other protein deficiencies cause hereditary elliptocytosis, pyropoikilocytosis or stomatocytosis.
In longstanding cases and in patients who have taken iron supplementation or received numerous blood transfusions, iron overload may be a significant problem. This is a potential cause of heart muscle damage and liver disease. Measuring iron stores is therefore considered part of the diagnostic approach to hereditary spherocytosis.
An osmotic fragility test can aid in the diagnosis. In this test, the spherocytes will rupture in liquid solutions less concentrated than the inside of the red blood cell. This is due to increased permeability of the spherocyte membrane to salt and water, which enters the concentrated inner environment of the RBC and leads to its rupture. Although the osmotic fragility test is widely considered the gold standard for diagnosing hereditary spherocytosis, it misses as many as 25% of cases. Flow cytometric analysis of eosin-5′-maleimide-labeled intact red blood cells and the acidified glycerol lysis test are two additional options to aid diagnosis.
Hereditary pyropoikilocytosis (HPP) is an autosomal recessive form of hemolytic anemia characterized by an abnormal sensitivity of red blood cells to heat and erythrocyte morphology similar to that seen in thermal burns. Patients with HPP tend to experience severe haemolysis and anaemia in infancy that gradually improves, evolving toward typical elliptocytosis later in life. However, the hemolysis can lead to rapid sequestration and destruction of red cells. Splenectomy is curative when this occurs.
HPP has been associated with a defect of the erythrocyte membrane protein spectrin and with spectrin deficiency.It was characterized in 1975.It is considered a severe form of hereditary elliptocytosis.
Congenital hemolytic anemia (or hereditary hemolytic anemia) refers to hemolytic anemia which is primarily due to congenital disorders.
Genetic testing for the presence of mutations in protein molecules is considered to be a confirmatory testing technique. It is important to know the risks regarding the transmission and dangers of HPP.
Microcytic anaemia is any of several types of anaemia characterized by small red blood cells (called microcytes). The normal mean corpuscular volume (abbreviated to MCV on full blood count results) is 80-100 fL, with smaller cells (100 fL) as macrocytic (the latter occur in macrocytic anemia).The MCV is the average red blood cell size.
In microcytic anaemia, the red blood cells (erythrocytes) are usually also hypochromic, meaning that the red blood cells appear paler than usual. This is reflected by a lower-than-normal mean corpuscular hemoglobin concentration (MCHC), a measure representing the amount of hemoglobin per unit volume of fluid inside the cell; normally about 320-360 g/L or 32-36 g/dL. Typically, therefore, anemia of this category is described as "microcytic, hypochromic anaemia".
Basically classified by causative mechanism, types of congenital hemolytic anemia include:
- Genetic conditions of RBC Membrane
- Hereditary spherocytosis
- Hereditary elliptocytosis
- Genetic conditions of RBC metabolism (enzyme defects). This group is sometimes called "congenital nonspherocytic (hemolytic) anemia", which is a term for a congenital hemolytic anemia without spherocytosis, and usually excluding hemoglobin abnormalities as well, but rather encompassing defects of glycolysis in the erythrocyte.
- Glucose-6-phosphate dehydrogenase deficiency (G6PD or favism)
- Pyruvate kinase deficiency
- Aldolase A deficiency
- Hemoglobinopathies/genetic conditions of hemoglobin
- Sickle cell anemia
- Congenital dyserythropoietic anemia
- Thalassemia
Typical causes of microcytic anemia include:
- Childhood
- Iron deficiency anemia, by far the most common cause of anemia in general and of microcytic anemia in particular
- Thalassemia
- Adulthood
- Iron deficiency anemia
- Sideroblastic anemia, In congenital sideroblastic anemia the MCV (mean corpuscular volume) is either low or normal. In contrast, the MCV is usually high in the much more common acquired sideroblastic anemia.
- Anemia of chronic disease, although this more typically causes normochromic, normocytic anemia. Microcytic anemia has been discussed by Weng et al.
- Lead poisoning
- Vitamin B (pyridoxine) deficiency
Other causes that are typically thought of as causing normocytic anemia or macrocytic anemia must also be considered, and the presence of two or more causes of anemia can distort the typical picture.
There are five main causes of microcytic anemia forming the acronym TAILS. Thalassemia, Anemia of chronic disease, Iron deficiency, Lead poisoning and Congenital sideroblastic anemia. Only the first three are common in most parts of the world. In theory, these three can be differentiated by their red blood cell (RBC) morphologies. Anemia of chronic disease shows unremarkable RBCs, iron deficiency shows anisocytosis, anisochromia and elliptocytosis, and thalessemias demonstrate target cells and coarse basophilic stippling. In practice though elliptocytes and anisocytosis are often seen in thalessemia and target cells occasionally in iron deficiency. All three may show unremarkable RBC morphology. Coarse basophlic stippling is one reliable morphologic finding of thalessemia which does not appear in iron deficiency or anemia of chronic disease. The patient should be in an ethnically at risk group and the diagnosis is not confirmed without a confirmatory method such as hemoglobin HPLC, H body staining, molecular testing or another reliable method. Course basophlic stippling occurs in other cases as seen in Table 1
A normocytic anemia is defined as an anemia with a mean corpuscular volume (MCV) of 80–100 which is the normal range. However, the hematocrit and hemoglobin is decreased.
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.
In general, signs of anemia (pallor, fatigue, shortness of breath, and potential for heart failure) are present. In small children, failure to thrive may occur in any form of anemia. Certain aspects of the medical history can suggest a cause for hemolysis, such as drugs, consumption of fava beans due to Favism, the presence of prosthetic heart valve, or other medical illness.
Chronic hemolysis leads to an increased excretion of bilirubin into the biliary tract, which in turn may lead to gallstones. The continuous release of free hemoglobin has been linked with the development of pulmonary hypertension (increased pressure over the pulmonary artery); this, in turn, leads to episodes of syncope (fainting), chest pain, and progressive breathlessness. Pulmonary hypertension eventually causes right ventricular heart failure, the symptoms of which are peripheral edema (fluid accumulation in the skin of the legs) and ascites (fluid accumulation in the abdominal cavity).
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 (intravascular hemolysis) or elsewhere in the human body (extravascular, but usually in the spleen). It has numerous possible consequences, ranging from relatively harmless to life-threatening. The general classification of hemolytic anemia is either inherited or acquired. Treatment depends on the cause and nature of the breakdown.
Symptoms of hemolytic anemia are similar to other forms of anemia (fatigue and shortness of breath), but in addition, the breakdown of red cells leads to jaundice and increases the risk of particular long-term complications, such as gallstones and pulmonary hypertension.
Cigar cells (also referred to as pencil cells) are red blood cells that are cigar or pencil shaped on Peripheral blood smear. Cigar cells are commonly associated with hereditary elliptocytosis. However, they may also be seen in iron deficiency anemia and other pathological states that decrease red blood cell turnover and or production. In the case of iron deficiency anemia, microcytosis and hypochromia would also be expected.
Kostmann syndrome is a group of diseases that affect myelopoiesis, causing a congenital form of neutropenia (severe congenital neutropenia [SCN]), usually without other physical malformations. SCN manifests in infancy with life-threatening bacterial infections.
Most cases of SCN respond to treatment with granulocyte colony-stimulating factor (filgrastim), which increases the neutrophil count and decreases the severity and frequency of infections. Although this treatment has significantly improved survival, people with SCN are at risk of long-term complications such as hematopoietic clonal disorders (myelodysplastic syndrome, acute myeloid leukemia).
Kostmann disease (SCN3), the initial subtype recognized, was clinically described in 1956. This type has an autosomal recessive inheritance pattern, whereas the most common subtype of Kostmann syndrome, SCN1, shows autosomal dominant inheritance.
Infants with SCN have frequent infections: 50% have a significant infection within 1 month, most others by 6 months. Their etiology is usually bacterial, especially staphylococcal, and they commonly involve abscesses, both cutaneous and of internal organs, pneumonia, mastoiditis (inflammation of the mastoid process), and sepsis. All of these are life-threatening for infants.
Southeast Asian ovalocytosis is a blood disorder that is similar to, but distinct from hereditary elliptocytosis. It is common in some communities in Malaysia and Papua New Guinea, as it confers some resistance to cerebral Falciparum Malaria.
The low incidence of this syndrome is often related to aldolase A's essential glycolytic role along with its exclusive expression in blood and skeletal muscle. Early developmental reliance and constitutive function prevents severe mutation in successful embryos. Infrequent documentation thus prevents clear generalisation of symptoms and causes. However five cases have been well described. ALDOA deficiency is diagnosed through reduced aldoA enzymatic activity, however, both physiological response and fundamental causes vary.
In non-contiguous patients an aggravated form of adolase-a deficiency has been seen to manifest in muscular deterioration. This is often recognized initially through signs of muscle weakness and exercise intolerance, suggesting rapid muscular fatigue and damage, likely directly related to ATP depletion. This breakdown of muscular fibers or, rhabdomyolysis, can lead to detectable blood creatine phosphate level elevation and potentially exaggerated hyperkalemia.
It is hereditary haemolytic anaemia in which the red blood cell is oval-shaped. The primary defect in SAO differs significantly from other forms of elliptocytosis in that it is a defect in the gene coding for a protein that is not directly involved in the cytoskeleton scaffolding of the cell. Rather, the defect lies in a protein known as the band 3 protein, which lies in the cell membrane itself. The band 3 protein normally binds to another membrane-bound protein called ankyrin, but in SAO this bond is stronger than normal. Other abnormalities include tighter tethering of the band 3 protein to the cell membrane, increased tyrosine phosphorylation of the band 3 protein, reduced sulfate anion transport through the cell membrane, and more rapid ATP consumption. These (and probably other) consequences of the SAO mutations lead to the following erythrocyte abnormalities:
- A greater robustness of cells to a variety of external forces, including:
- Reduction in cellular sensitivity to osmotic pressures
- Reduction in fragility related to temperature change
- greater general rigidity of the cell membrane
- Loss of sensitivity to substances that cause of cells
- Reduced anion exchange
- Partial intracellular depletion of ATP
- A reduction in expression of multiple antigens
These changes are thought to give rise to the scientifically and clinically interesting phenomenon that those with SAO exhibit: a marked "in vivo" resistance to infection by the causative pathogen of malaria, "Plasmodium falciparum". Unlike those with the Leach phenotype of common hereditary elliptocytosis (see above), there is a clinically significant reduction in both disease severity and prevalence of malaria in those with SAO. Because of this, the 35% incidence rate of SAO along the north coast of Madang Province in Papua New Guinea, where malaria in endemic, is a good example of natural selection.
The reasons behind the resistance to malaria become clear when given an explanation the way in which "Plasmodium falciparum" invades its host. This parasite is an obligate intracellular parasite, which must enter the cells of the host it is invading. The band 3 proteins aggregate on the cell membrane at the site of entry, forming a circular that the parasite squeezes through. These band 3 proteins act as receptors for the parasite. Normally a process much like endocytosis occurs, and the parasite is able to isolate itself from the intracellular proteins that are toxic to it while still being inside an erythrocyte (see figure 2). The increased rigidity of the erythrocyte membrane in SAO is thought to reduce the capacity of the band 3 proteins to cluster together, thereby making it more difficult for the malaria parasite to properly attaching to and enter the cell. The reduced free ATP within the cell has been postulated as a further mechanism behind which SAO creates a hostile environment for "Plasmodium falciparum".
Fibrinogen disorders are set of hereditary or acquired abnormalities in the quantity and/or quality of circulating fibrinogens. The disorders may lead to pathological bleeding and/or blood clotting or the deposition of fibrinogen in the liver, kidneys, or other organs and tissues. These disorders include:
- Congenital afibrinogenemia, an inherited blood disorder in which blood does not clot normally due to the lack of fibrinogen; the disorder causes abnormal bleeding and thrombosis.
- Congenital hypofibrinogenemia, an inherited disorder in which blood may not clot normally due to reduced levels of fibrinogen; the disorder may cause abnormal bleeding and thrombosis.
- Fibringogen storage disease, a form of congenital hypofibrinogenemia in which specific hereditary mutations in fibrinogen cause it to accumulate in, and damage, liver cells. The disorder may lead to abnormal bleeding and thrombosis but also to cirrhosis.
- Congenital dysfibrinogenemia, an inherited disorder in which normal levels of fibrinogen composed at least in part of a dysfunctional fibrinogen may cause abnormal bleeding and thrombosis.
- Hereditary fibrinogen Aα-Chain amyloidosis, a form of dysfibrinogenemia in which certain fibrinogen mutations cause blood fibrinogen to accumulate in the kidney and cause one type of familial renal amyloidosis; the disorder is not associated with abnormal bleeding or thrombosis.
- Acquired dysfibrinogenemia, a disorder in which normal levels of fibrinogen are composed at least in part of a dysfunctional fibrinogen due to an acquired disorder (e.g. liver disease) that leads to the synthesis of an incorrectly glycosylated (i.e. wrong amount of sugar residues) added to an otherwise normal fibrinogen. The incorrectly glycosalated fibrinogen is dysfunctional and may cause pathological episodes of bleeding and/or blood clotting.
- Congenital hypodysfibrinogenemia, an inherited disorder in which low levels of fibrinogen composed at least in part of a dysfunctional fibrinogen may cause pathological episodes of bleeding or blood clotting.
- Cryofibrinogenemia, an acquired disorder in which fibrinogen precipitates at cold temperatures and may lead to the intravascular precipitation of fibrinogen, fibrin, and other circulating proteins thereby causing the infarction of various tissues and bodily extremities.
Acquired dysfibrinogenemia occurs as a known or presumed consequence of an underlying disease which directly or indirectly interferes with the clotting function of fibrinogen. Individuals with acquired dysfibrinogenemias have a greater tendency for bleeding complications than those with congenital fibrinogenemia. The following Table gives some abnormalities, causes, and apparent pathophysiology along with some comments on examples of acquired dysfibrinogenmeia.
Acquired dysfibrinogenemia commonly present with signs, symptoms, and/or prior diagnoses of the underlying causative disease or drug intake in an individual with an otherwise unexplained bleeding tendency or episode. Bleeding appears to be more prominent in acquired compared to congenital dysfibrinogenemia; pathological thrombosis, while potentially occurring in these individuals as a complication of their underlying disease, is an uncommon feature of the acquired disorder.
CCD causes persistent secretory diarrhea. In a fetus, it leads to polyhydramnios and premature birth. Immediately after birth, it leads to dehydration, hypoelectrolytemia, hyperbilirubinemia, abdominal distention, and failure to thrive.