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Multiple blood transfusions can result in iron overload. The iron overload related to thalassemia may be treated by chelation therapy with the medications deferoxamine, deferiprone, or deferasirox. These treatments have resulted in improving life expectancy in those with thalassemia major.
Deferoxamine is only effective via daily injections which makes its long-term use more difficult. It has the benefit of being inexpensive and decent long-term safety. Adverse effects are primary skin reactions around the injection site and hearing loss.
Deferasirox has the benefit of being an oral medication. Common side effects include: nausea, vomiting and diarrhea. It however is not effective in everyone and is probably not suitable in those with significant cardiac issues related to iron overload. The cost is also significant.
Deferiprone is a medication that is given by mouth. Nausea, vomiting, and diarrhea are relatively common with its use. It is available in both Europe and the United States. It appears to be the most effective agent when the heart is significantly involved.
There is no evidence from randomized controlled trial to support zinc supplementation in thalassemia.
People with severe thalassemia require medical treatment. A blood transfusion regimen was the first measure effective in prolonging life.
Iron overload is an unavoidable consequence of chronic transfusion therapy, necessary for patients with beta thalassemia. Iron chelation is a medical therapy that avoids the complications of iron overload. The iron overload can be removed by Deferasirox, an oral iron chelator, which has a dose- dependent effect on iron burden. Every unit of transfused blood contains 200–250 mg of iron and the body has no natural mechanism to remove excess iron. Deferasirox is a vital part in the patients health after blood transfusions. During normal iron homeostasis the circulating iron is bound to transferrin, but with an iron overload, the ability for transferrin to bind iron is exceeded and non-transferrin bound iron is formed. It represents a potentially toxic iron form due to its high propensity to induce oxygen species and is responsible for cellular damage. The prevention of iron overload protects patients from morbidity and mortality. The primary aim is to bind to and remove iron from the body and a rate equal to the rate of transfusional iron input or greater than iron input. During clinical trails patients that received Deferasirox experienced no drug-related neutropenia or agranulocytosis, which was present with other iron chelators. Its long half life requires it to be taken once daily and provides constant chelation. Cardiac failure is a main cause of illness from transfusional iron overload but deferasirox demonstrated the ability to remove iron from iron-loaded myocardial cells protecting beta thalassemia patients from effects of required blood transfusions.
Long-term transfusion therapy to maintain the patient’s hemoglobin level above 9-10 g/dL (normal levels are 13.8 for males, and 12.1 for females). Patients are transfused by meeting strict criteria ensuring their safety. They must have: confirmed laboratory diagnosis of thalassemia major, and hemoglobin levels less than 7g/dL, to be eligible for the transfusion. To ensure quality blood transfusions, the packed red blood cells should be leucoreduced with a minimum of 40g of hemoglobin content. By having leucoreduced blood packets, the patient is at a lower risk to develop adverse reactions by contaminated white cells and preventing platelet alloimmunisation. Pre-storage filtration of whole blood offers high efficiency for removal and low residual of leukocytes; It is the preferred method of leucoreduction compared to pre-transfusion and bedside filtration. Patients with allergic transfusion reactions or unusual red cell antibodies must received “washed red cells” or “cryopreserved red cells.” Washed red cells have been removed of plasma proteins that would have become a target of the patient’s antibodies allowing the transfusion to be carried out safely. Cryopreserved red cells are used to maintain a supply of rare donor units for patients with unusual red cell antibodies or missing common red cell antigens. The transfusion programs available involve lifelong regular blood transfusion to main the pre-transfusion hemoglobin level above 9-10 g/gL. The monthly transfusions promote normal growth, physical activities, suppress bone marrow activity, and minimize iron accumulation. It has been announced the starting of the first clinical trial with CRISPR/Cas9 in Europe in 2018.
Treatment is the same as for patients with sickle cell disease. Patients may receive hydroxyurea to induce the protective effects of increased fetal hemoglobin production. They may also benefit from blood transfusions especially during vaso-occlusive crises. Patients may be offered chemoprophylaxis with penicillin. They may have splenic dysfunction and splenectomy is frequently performed. Vaccination against encapsulated bacteria including Streptococcus pneumoniae is recommended.
Treatment for alpha-thalassemia may consist of blood transfusions, and possible splenectomy; additionally, gallstones may be a problem that would require surgery. Secondary complications from febrile episode should be monitored, and most individuals live without any need for treatment
Additionally, stem cell transplantation should be considered as a treatment (and cure), which is best done in early age. Other options, such as gene therapy, are still being developed.
In terms of treatment for delta-beta thalassemia one possible concern would be anemia, where, therefore, blood transfusions would be given to the affected individual (though blood transfusions might introduce complications, as well).
Stem cell transplant is another option, but the donor and the individual who will receive the bone marrow transplant must be compatible, the risks involved should be evaluated, as well
Gene therapy, as well as, bone marrow transplant are also possible treatments for the disorder, but each have their own risks at this point in time. Bone marrow transplantation is the more used method between the two, whereas researchers are still trying to definitively establish the results of gene therapy treatment. It generally requires a 10/10 HLA matched donor, however, who is usually a sibling. As most patients do not have this, they must rely on gene therapy research to potentially provide them with an alternative. CDA at both clinical and genetic aspects are part of a heterogeneous group of genetic conditions. Gene therapy is still experimental and has largely only been tested in animal models until now. This type of therapy has promise, however, as it allows for the autologous transplantation of the patient's own healthy stem cells rather than requiring an outside donor, thereby bypassing any potential for graft vs. host disease (GVHD).
In the United States, the FDA approved clinical trials on Beta thalassemia patients in 2012. The first study, which took place in July 2012, recruited human subjects with thalassemia major, and ended in 2014.
Treatment of individuals with CDA usually consist of frequent blood transfusions, but this can vary depending on the type that the individual has. Patients report going every 2–3 weeks for blood transfusions. In addition, they must undertake chelation therapy to survive; either deferoxamine, deferasirox, or deferiprone to eliminate the excess iron that accumulates. Removal of the spleen and gallbladder are common. Hemoglobin levels can run anywhere between 8.0 g/dl and 11.0 g/dl in untransfused patients, the amount of blood received by the patient is not as important as their baseline pre-transfusion hemoglobin level. This is true for ferritin levels and iron levels in the organs as well, it is important for patients to go regularly for transfusions in order to maximize good health, normal ferritin levels run anywhere between 24 and 336 ng/ml, hematologists generally do not begin chelation therapy until ferritin levels reach at least 1000 ng/ml. It is more important to check iron levels in the organs through MRI scans, however, than to simply get regular blood tests to check ferritin levels, which only show a trend, and do not reflect actual organ iron content.
Individuals heterozygous for the Hb Lepore request no particular treatment. There is no anemia or, if there is, it is very mild.
Treatment is by phlebotomy, erythrocytapheresis or chelation therapy with iron chelating agents such as deferoxamine, deferiprone or deferasirox.
If iron overload has caused end-organ damage, this is generally irreversible and may require transplantation.
A potential complication that may occur in children that suffer acute anemia with a hemoglobin count below 5.5 g/dl is silent stroke A silent stroke is a type of stroke that does not have any outward symptoms (asymptomatic), and the patient is typically unaware they have suffered a stroke. Despite not causing identifiable symptoms a silent stroke still causes damage to the brain, and places the patient at increased risk for both transient ischemic attack and major stroke in the future.
Hypochromic anemia may be caused by vitamin B6 deficiency from a low iron intake, diminished iron absorption, or excessive iron loss. It can also be caused by infections (e.g. hookworms) or other diseases (i.e. anemia of chronic disease), therapeutic drugs, copper toxicity, and lead poisoning. One acquired form of anemia is also known as Faber's syndrome. It may also occur from severe stomach or intestinal bleeding caused by ulcers or medications such as aspirin or bleeding from hemorrhoids.
Hypochromic anemia occurs in patients with hypochromic microcytic anemia with iron overload. The condition is autosomal recessive and is caused by mutations in the SLC11A2 gene. The condition prevents red blood cells from accessing iron in the blood, which causes anemia that is apparent at birth. It can lead to pallor, fatigue, and slow growth. The iron overload aspect of the disorder means that the iron accumulates in the liver and can cause liver impairment in adolescence or early adulthood.
It also occurs in patients with hereditary iron refractory iron-deficiency anemia (IRIDA). Patients with IRIDA have very low serum iron and transferrin saturation, but their serum ferritin is normal or high. The anemia is usually moderate in severity and presents later in childhood.
Hypochromic anemia is also caused by thalassemia and congenital disorders like Benjamin anemia.
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
Congenital hemolytic anemia (or hereditary hemolytic anemia) refers to hemolytic anemia which is primarily due to congenital disorders.
Ted DeVita died of transfusional iron overload from too many blood transfusions.
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
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".
Because of the microcirculatory distress, a telltale sign or symptom of a potential sickling collapse is cramping. Specifically to sickle cell trait, cramping occurs in the lower extremities and back in athletes undergoing intense physical activity or exertion. In comparison to heat cramps, sickling cramps are less intense in terms of pain and have a weakness and fatigue associated with them, as opposed to tightly contracted muscles that lock up during heat cramps.
A sickling collapse comes on slowly, following cramps, weakness, general body aches and fatigue. Individuals with known positive sickle cell trait status experiencing significant muscle weakness or fatigue during exercise should take extra time to recover and hydrate before returning to activity in order to prevent further symptoms.
A collapse can be prevented by taking steps to ensure sufficient oxygen levels in the blood. Among these preventative measures are proper hydration and gradual acclimation to conditions such as heat, humidity, and decreased air pressure due to higher altitude. Gradual progression of exertion levels also helps athletes' bodies adjust and compensate, gaining fitness slowly over the course of several weeks.
Microcytosis is a condition in which red blood cells are unusually small as measured by their mean corpuscular volume.
It is also known as "microcythemia". When associated with anemia, it is known as microcytic anemia.
Microcytic anemia is not caused by reduced DNA synthesis.
Thalassemia can cause microcytosis. Depending upon how the terms are being defined, thalassemia can be considered a cause of microcytic anemia, or it can be considered a cause of microcytosis but not a cause of microcytic anemia.
There are many causes of microcytosis, which is essentially only a descriptor. Cells can be small because of mutations in the formation of blood cells (hereditary microcytosis) or because they are not filled with enough hemoglobin, as in iron-deficiency-associated microcytosis.
Red blood cells can be characterised by their haemoglobin content as well as by their size. The haemoglobin content is referred to as the cell's colour. Therefore, there are both "normochromic microcytotic red cells" and "hypochromic, microcytotic red cells". The normochromic cells have a normal concentration of haemoglobin, and are therefore 'red enough' while the hypochromic cells do not; thus the value of the mean corpuscular hemoglobin concentration.
Anisocytosis is a medical term meaning that a patient's red blood cells are of unequal size. This is commonly found in anemia and other blood conditions. False diagnostic flagging may be triggered by an elevated WBC count, agglutinated RBCs, RBC fragments, giant platelets or platelet clumps. In addition, it is a characteristic feature of bovine blood.
The red cell distribution width (RDW) is a measurement of anisocytosis and is calculated as a coefficient of variation of the distribution of RBC volumes divided by the mean corpuscular volume (MCV)
Delta-beta thalassemia is a form of thalassemia, and is autosomal recessive in terms of heredity. It is associated with "hemoglobin subunit delta"
Anisocytosis is identified by RDW and is classified according to the size of RBC measured by MCV. According to this, it can be divided into
- Anisocytosis with microcytosis – Iron deficiency, sickle cell anemia
- Anisocytosis with macrocytosis – Folate or vitamin B deficiency, autoimmune hemolytic anemia, cytotoxic chemotherapy, chronic liver disease, myelodysplastic syndrome
Increased RDW is seen in iron deficiency anemia and decreased or normal in thalassemia major (Cooley's anemia), thalassemia intermedia
- Anisocytosis with normal RBC size – Early iron, vit B12 or folate deficiency, dimorphic anemia, Sickle cell disease, chronic liver disease, Myelodysplastic syndrome