Anaemias Flashcards
Aplastic anaemia
Cause: Failure of bone marrow development, caused by toxins, gamma radiation and certain medications that inhibit enzymes needed for hemopoiesis
Symptoms: Sore throat and mouth, hemorrhages in skin on backs of hands and forearms
Autoimmune haemolytic anaemia
Cause: occurs when antibodies directed againt the person’s own red blood cells (RBCs) cause them to lyse, leading to an insufficient number of oxygen carrying red blood cells in circulation
Symptoms: short of breath, pale, jaundice, enlarged spleen and swelling of lymphatics
Congential spherocytosis
Cause: An inherited gene, characterised by abnormal red blood cells called spherocytes that are thin and fragile. These cells cannot change shape to pass through certain organs as normal RBCs do, so they stay in the Spleen longer, where they are eventually destroyed
Symptoms: Most people with hereditary spherocytosis have only mild anaemia, but stresses on the body from infection can cause jaundice and even a temporary halt in the bone marrow’s production of blood cells.
Essential thrombocythemia
Causes: A rare chronic blood disorder characterised by the overproduction of platelets by megakaryocytes in the bone marrow. It may develop into acute myeloid leukemia or myelofibrosis
Symptoms: bleeding, blood clots, headache, nausea, vomitting, abdominal pain, visual disturbances, dizziness, fainting and numbness in the extremities; the most common signs are increased white blood cell count, reduced red blood cell count and enlarged spleen
Hypersplenism (Splenomegaly)
Four cardinal (greatest importance) signs of hypersplenism are; some reduction in the number of circulating blood cells affecting granulocytes, erythrocytes or platelets in any combination, a compensatory proliferative response in the bone marrow, and the potential for correction of these abnormalities by splenectomy. It is usually associated with increased workload, which suggests hyperfunction Symptoms: an enlarged spleen, along with caput medusae, is an important sign of portal hypertension.
Megaloblastic anaemia
Cause: Megaloblastic anaemia, the most common cause of macrocytic anaemia, is due to a deficiency of either vitamin B12, folic acid, or both. Deficiency in folate and/or vitamin B12 can be due either to inadequate intake or insufficient absorption. Pernicious anaemia is caused by a lack of intrinsic factor, which is required to absorb vitamin B12 from food. A lack of intrinsic factor may arise from an autoimmune condition targeting the parietal cells (atrophic gastritis) that produce intrinsic factor or against intrinsic factor itself. These lead to poor absorption of vitamin B12.
microcytic anaemia
Microcytic anaemia is primarily a result of haemoglobin synthesis failure or insufficiency, which could be caused by several etiologies (set of causes):
Haem synthesis defect
Iron deficiency anaemia
Anaemia of chronic disease
Globin synthesis defect
Alpha and beta thalassemia (any of a group of hereditary haemolytic diseases caused by faulty haemoglobin synthesis, widespread in Mediterranean, African, and Asian countries.)
HbE/HbC syndrome
Various other unstable haemoglobin diseases
Iron deficiency anaemia is the most common type of anaemia overall and it has many causes including insufficient dietary intake, blood loss, and parasitic infestation. RBCs often appear hypochromic (paler than usual) and microcytic (smaller than usual) when viewed with a microscope.
Normocytic normochromic anaemia
Normocytic anaemia occurs when the overall haemoglobin levels are decreased, but the RBC size (mean corpuscular volume) remains normal. Causes include:
Acute blood loss (haemorrhagic anaemia)
Anaemia of chronic disease
Aplastic anaemia (destruction of bone marrow) - caused by toxins, gamma radiation, and certain medications that inhibit enzymes needed for hemopoiesis
Hemolytic anaemia - RBC plasma membranes rupture prematurely
Symptoms: reduced serum iron and reduced total iron binding capacity, but a normal serum ferritin
Polycythemia
A disease state in which the hematocrit (the volume percent of red blood cells in the blood) is >55%.It can be due to an increase in the number of red blood cells (“absolute polycythemia”) or to a decrease in the volume of plasma (“relative polycythemia”). Polycythemia is sometimes called erythrocytosis, but the terms are not synonymous because polycythemia refers to any increase in red blood cells, whereas erythrocytosis only refers to a documented increase of red cell mass. The overproduction of red blood cells may be due to a primary process in the bone marrow (a so-called myeloproliferative syndrome), or it may be a reaction to chronically low oxygen levels or, rarely, a malignancy.
Sickle cell anaemia
People with sickle-cell anaemia have a gene that causes the blood protein haemoglobin to form abnormally. As a result, RBCs are produced in a sickle shape. People with sickle-cell anaemia may experience ‘crises’, swelling in hands and feet, reduced ability to fight infection, and even strokes and heart attacks.
Sideroblastic anaemia
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 to transport oxygen efficiently. The disorder may be caused either by a genetic disorder or indirectly as part of myelodysplastic syndrome, which can evolve into hematological malignancies (especially acute myelogenous leukemia).
Thalassaemia
Thalassemia occurs when your body is unable to produce enough haemoglobin, which functions to carry oxygen throughout the body. This condition is also caused by faulty genes (autosomal recessive). People with mild thalassemia often experience typical symptoms of anaemia, such as tiredness, while those with a moderate or severe form may have an enlarged spleen, slowed growth, bone problems, and jaundice.
