Week 231 - Anaemia Flashcards
Week 231
Anaemia in Adult Males is considered as an Hb Value less than what?
<13.5g/dl
Week 231
Anaemia in Adult Females is considered as an Hb Value less than what?
Hb <11.5 g/dl
Week 231
What is an Erythrocyte?
This is a fully developed red blood cell.
Week 231
How many new Erythrocytes are made each day?
1012 New Erythrocytes
Week 231
What is the primary site of EPO synthesis?
The peritubular cells of the kidneys (Renal cortex).
Week 231
How is EPO production triggered?
EPO is not stored. Like most physiological cycles, it is a negative feedback cycle. The production of EPO is triggered by tissue hypoxia (oxygen tension in the tubules of the kidney).
Week 231
What is the major stimulant for EPO production?
Hypoxia
Week 231
Chronic renal disease/Bilateral nephrectomy will stop or reduce the production of which growth factor?
EPO
Week 231
A failure of production of EPO causes what type of Anaemia?
Normacytic anaemia. The red cells will be a normal shape and size, but there will be less of them.
Week 231
In cases of chronic haemolysis, as in thalassaemia, EPO production rises as a result of chronic hypoxia. What effect(s) does this have?
An increase in EPO eads to an increase in the numbers of erythrocytes (red blood cells), resulting in expansion and eventually fatty deposition within the bone marrow. In children, this can cause growth deformities like Frontal Bossing.
Week 231
When do reticulocyte counts rise?
- Haemorrhage
- Haemolytic anaemia
- Treatment of a haemotinic deficiency
Week 231
What is the ratio of reticulocyte to red blood cell count in a normal human being?
1:100 Reticulocyte:Red blood cell
Week 231
What is a pronormoblast?
This is the earliest stage of the erythrocyte, formed from stem cells. They have a large nucleus, and no haemoglobin.
Week 231
What are normoblasts?
A precursor to red blood cells. There is still a nucleus, but through the many variations of normoblasts, this gradually decreases. Eventually it is extruded from the cell and released into the blood.
Week 231
What % of the final Haemoglobin do reticulocytes contain?
25%
Week 231
What is anaemia of chronic disease?
Anaemia of chronic disease. Within any individual who lives with a chronic disease (eg rheumatoid arthritis),a complex interaction of
inflammatory cytokines interferes with the red cell lifecycle by
impairing iron metabolism and inhibiting red cell precursors.
The end result is a normocytic anaemia.
Week 231
If asked to “check the haemotinics”, what do you look at?
Iron
Vitamin B12
Folate
Week 231
Iron content is rate-limiting for erythropoiesis. So, in iron deficiency anaemia, the cells are ___. This is known as ______ ______.
The red cells are smaller in size This is known as microcytic anaemia.
Week 231
What is the term used to describe low haemoglobin?
Hypochromic
Week 231
Vitamin B12 and Folate are used for which two important processes?
DNA Synthesis and Cell Mitoses.
Week 231
A Vitamin B12 or a folate deficiency leads to what?
These are important for DNA production and cell mitosis. A Lack means that cell formation and production happens more slowly. It leads to the productino of magaloblasts (enlarged, misshapen cells)!
Week 231
How much Ferrous Iron is absorbed from the small intestine every day in a healthy adult?
1mg/day
Week 231
Which protein does Iron attach to in the serum, and what is its function?
The protein is called Transferrin. It binds to iron, and transports it to the bone marrow.
Week 231
Which receptors are increased in iron deficiency?
Soluble Transfferin receptors. sTfR.
Week 231
What is ferritin?
It is a storage compound. Stored in the liver.
Week 231
Where are dying red blood cells recycled?
The spleen. This is where iron is recycled into the plasma for future use.
Week 231
Describe the iron deficieny PROFILE.
- Serum Iron is reduced
- Serum total iron binding capacity is increased. The body is working hard to bind any iron that is left.
- Serum ferritin is reduced since iron stores are low.
- Serum soluble transferrin receptors are increased since any iron in the system is being used up.
Week 231
Give causes of Vitamin B12 deficiency
- Pernicious anaemia
- Inadequate intake
- Poor absorbtion
Week 231
What is the leading cause of B12 deficiency?
Pernicious anaemia.
- Igg autoantibodies target parietal cells, and its product (intrinsic factor IF)
- This basically means that less B12-IF is absorbed in the terminal ileum. BAD TIMES.
Week 231
What are the four proteins of importance in red blood cells?
Spectrin
Actin
Protein 4.1
Ankyrin
Week 231
Defects in the structural proteins that form red blood cells can cause what?
These cells cannot withstand the shear forces of the microcirculation. Their shape changes (eg they become elliptical). These then get destroyed within the spleen by macrophages. This is haemolytic anaemia.
Week 231
Hereditary spherocytosis and elliptocytosis are examples of what?
Haemolytic anaemia. These are both due to defets in the Spectrin, one of four major protein components in the red blood cell.
Week 231
What is Thalassaemia?
There is a reduced rate of synthesis of either alpha or Beta globin chains. Within this group of inherited conditions, there may be both ineffective erythropoiesis, and haemolysis, leading to hypochromic (low iron) normacytic (normal size) anaemia.
Week 231
What is sickle-cell disease?
There is an inheritance of two abnormal Beta chains (HbSS). The abnormality is a point mutation. This causes insolubility in the cells deoxygenated state, and crystalisation within the red blood cell. This…leads to sickle cell deformity, and vascular occlusion. Most often seen in Afro-Carribean populations.
Week 231
What is 2,3 - diphosphoglycerate?
This sits in between beta chains in haemoglobin, and helps to offload oxygen.
Week 231
The change from foetal to adult haemoglobin occurs at 3-6 months. What is the difference between adult and foetal haemoglobin?
Foetal Haemoglobin has a higher affinity for oxygen than adult haemoglobin.
Week 231
In metabolic alkalosis, what happens to the oxygen dissociation curve?
With an increased pH, CO2 is decreased, and the curve shifts to the LEFT. This means there is a higher affinity for oxygen in the lungs, and it is “harder” to release oxgen to tissues. This also occurs with foetal haemoglobin.