Anaemias Flashcards
What is erythrocytosis?
Excess red cells only
What is polycythaemia?
Excess red cells as well as others such as WBC and/or platelets
What is pancytopenia?
Low levels of all types of blood cells, often arise when bone marrow is invaded by cancer originating from other organs, or from external factors such as drugs and infectious agents. Anaemia associated with pancytopenia is called aplastic anaemia
What is pure red cell aplasia (PRCA)?
It is the most common form of red cell aplasia due to absent or reduced numbers of erythroblasts leading to the reduction of red cells alone. It can appear as congenital condition or acquired syndrome, congenital being more common
What is erythroid hyperplasia?
Increased numbers of erythroblasts where erythropoiesis is ineffective
What is the difference between myeloma and lymphoma?
Myeloma - WBC multiply in an inappropriate manner
Lymphoma - WBC tumour centred on the lymph node
What is myelofibrosis?
Marrow becomes overgrown with fibroblasts
What absorbs ferrous iron into the enterocytes?
Absorbed through the transmembrane protein divalent metal transport-1 (DMT-1), which is found in the luminal surface if the enterocytes of the duodenum and jejunum
How is ferric iron absorbed?
Ferric iron is poorly absorbed but can be converted to ferrous iron by the luminal enzyme iron-reductase, which functions bets at a low pH and is present in the stomach
What is sideroblastic anaemia?
The failure to incorporate iron into haemoglobin in red cell precursors. When a mutation occurs for the synthesis of haemoglobin on the X-chromosome, synthesis is impaired, leading to a build-up of iron in the mitochondria, creating sideroblasts. They can still mature into red cells but they contain iron inclusion granules called Pappenheimer bodies and can be viewed under a Perls stain
How can the lack of copper lead to sideroblastic anaemia?
Copper is a cofactor for enzymes involved in haemoglobin synthesis. Excess of zinc can also cause this as it inhibits the absorption of copper in the intestines
What is the most common genetic cause of iron overload?
Hereditary haemochromatosis (HH), 83% caused by mutations in HFE (human haemochromatosis protein)
What lab results are associated with iron deficiency?
Low MCV, low MCH, low MCHC with pencils and target cells
What ate the two methods to treat iron overload?
Iron-chelating therapy and venesection (bleeding from a vein)
