Anaemia Flashcards
What are young RBCs called which have a nucleus
Erythroblasts
What is enucleation and when does it occur
Erythrocyte getting rid of nucleus before leaving bone marrow
What helps keep iron in the ferrous Fe2+ form
Ascorbic acid
What are folic acid and vitamin B12 used for
In production of the nucleotide base thymine
Essential for production of DNA during erythropoiesis
What does the presence of reticulocytes suggest
Bone marrow is active in producing RBCs
Plenty of Iron , folate and vitamin B12 available for erythropoiesis
What is anaemia? What values diagnose it in males vs females?
Decreased haemoglobin concentration
Females : below 11.5g/dL
Males : below 13.5 g/dL
Name three types of anaemia
Iron deficiency anaemia (microcytic anemia)
Normochromic normocytic anaemia
Macrocytic anaemia
What is anisocytosis?
variation in RBC size
What is poikilocytosis
variation in RBC shape
What is iron deficiency anaemia also known as
Microcytic (hypochromic) anaemia
What is a common feature of iron deficiency anaemia
Increased platelet count
What is ferritin
Protein in which iron is bound in liver
What are the physical signs of leukaemia
Expansions of the abdomen - extramedullary haematopoiesis causes splenomegaly and hepatomegaly
Splenomegaly - enlarged spleen
Hepatomegaly - englarged liver
What is leukaemia?
A cancer of white blood cells/leukocytes.
Young abnormal WBCs are spilling out of bone marrow
Why does leukaemia result in increased likelihood for infections
WBCs produced are of one clone and therefore unable to respond to a range of infections
Why do leukaemia patients bruise easily?
Low platelet count
What is normocytic normochromic anemia?
RBC’s are normal in size and Hb content, but are too few in number (lack of EPO)
Anaemia caused by another underlying condition
Microcytic anaemia
Iron deficiency
Causes of macrocytic anaemia
Dietary deficiency of B12 and folate (folic acid)
Pernicious anaemia: autoimmune disease, B12 is not absorbed.
Diagnosis?
Microcytic anaemia
Causes of microcytic anaemia
Iron deficiency can be caused by:
- dietary deficiency of iron (vegetarian diet)
- malabsorption (gastrectomy, coeliac disease)
- chronic blood loss (menstruation, ulceration of stomach or duodenum, colonic carcinoma, hookworm and schistosomiasis)
Serum ferritin and transferrin saturation importance in an iron deficiency patient?
- Most of iron is bound up in a protein in the liver called ferritin
- A Transferrin Saturation of less than 20% suggests iron deficiency anaemia (iron circulates in the blood attached to a plasma protein called transferrin)
- There is an increased rate of cell division of the red cell precursor cells in an iron-deficient environment leading to the individual cells to be smaller (microcytic anaemia)
Diagnosis?
Normochromic normocytic anaemia, very high WBC and low PLT indicates acute myeloid leukaemia.
Diagnosis?
Macrocytic anaemia
Why would a patient with macrocytic anaemia experience pins + needles?
- Vitamin B12 is used in the maintenance of myelin sheaths in the nervous system
- Therefore, deficiency of Vitamin B12 can lead to dysfunction of the nervous system including peripheral nerves and the spinal cord
Sickle cell disease genetics
- Single base mutation on the gene responsible for the production of β-globin chain —> replacement of glutamic acid (glutamate) with Valine
- High altitudes: amount of O2 in the air is reduced —> amount of O2 bound to RBCs is reduced = hypoxemia
- Abnormal B-globin chains in the Hb molecules within RBC interact with each other and polymerise to form a rigid structure within the cytoplasm —> deformation of the entire cell —> sickle-shaped
- Sickle shaped cells = unable to pass through the sinusoids in the spleen —> engorged with blood —> stretches capusle —> pain in left upper part of abdomen
If haemolysis is the cause of anaemia what type of RBC will be prominent?
Increased reticulocyte count
Hereditary Spherocytosis
- Caused by a deficiency of Spectrin (membrane protein) —> loss of surface area of RBC membrane —> forces the cell to take on a spherical shape
- Spherocytes unable to squeeze through the sinus in the spleen —> prematurely trapped and broken down
- Increased rate of haemolysis can cause jaundice and anaemia
- Splenomegaly = common feature
What nutrients are essential for the production of RBCs (erythropoiesis)?
Iron, Vitamin B12 and folate
Anaemia occurs when there’s either: (4 things)
- Decreased rate of production of RBCs
- Increased rate of destruction of RBCs (haemolysis)
- Loss of RBCs due to blood loss
- Impaired production of RBC due to a lack of one of the nutrients needed for their production
Why are there few reticulocytes in a patient who has leukaemia?
All the bone marrow is involved in production of abnormal and useless WBCs —> little space for erythropoiesis —> reticulocyte count is reduced
What hormone stimulates production of RBCs? Disease of which organs causes decreased production of this hormone?
- Erythropoietin (EPO)
- Chronic kidney disease (cause by diabetes for instance)
Other cause of a normochromic normocytic anaemia?
Renal failure
If HGB low and MCV low
Microcytic anaemia (iron deficiency)
If HGB low and MCV high
Macrocytic anaemia (low B12 and folate)
If HGB low and MCV normal
Normocytic anemia (low EPO)
