Anaemia Flashcards
What is an erythrocyte more commonly known as?
- RBC
What is erythropoiesis?
- RBC production that occurs in bone marrow
How many alpha and beta globulins are generally present in RBCs?
- 2 alpha
- 2 beta
- globulins are made up of 2 polypeptide chains
How many iron and heme molecules are present in one haemoglobin molecule?
- 4 of each
- heme binds to globulin
- iron binds to heme (4 O2 can bind to each haemoglobulin)
What is the iron state when O2 is and is not bound to haemoglobulin?
- Fe3+ when bound to O2
- Fe2+ when unbound to O2
What is anaemia?
- lack of haemoglobulin in blood
- causes lack of O2 in blood
What are the 2 most common causes of anaemia?
- low RBCs
- low haemoglobulin content
What is haematocrit?
- ratio of the volume of red blood cells to the total volume of blood
- normal level is around 45%
What is mean cell volume, referred to as MCV?
- the avaerage size of the RBCs
- normal is 80-120fL
What is the basis upon how cell counters work?
- they detect change in impredance
- change is determined by the volume
When spinning blood, what are the 3 layers at the end?
- RBCs at the bottom
- buffy coat in middle (platelets and WBCs)
- plasma containing proteins
When trying to understand the cause of anaemia, what are the 4 things that need to be considered? Remember that RVCs are like money.
- not making enough RBCs (impaired erythropoiesis)
- spending too much RBCs (cancer)
- lost RBCs (trauma)
- hidden RBCs (bleeding internally)
When categorising anaemia, RBC can be grouped based on their size, which is linked to the cause. What are the 3 sizes RBCs can be grouped as?
- microcytic = small (<75fl)
- macrocytic = large (>96fl)
- normacytic = 80-96fL
What is generally the cause of microcytic anaemia?
- haemoglobin problems
- iron deficiency (need more iron molecules)
- inherited disorders (thalassaemia - globulin molecules not made)
What is the most common cause of microcytic anaemia worldwide?
- iron deficiency
What are the common causes of macrocytic anaemia?
- B12 deficiency (cobalamin)
- folic acid deficiency (B9)
Why do B12 (cobalamin) and/or folic acid cause macrolytic anaemia?
- both are needed to make DNA
- RBCs are enlarged due to defects in synthesis
Myelodysplasia is a cause of macrocytic anaemia. What is this?
- abnormal RBCs due to ageing or genetic mutations
- DNA is unable to make RBCs
What are the 3 most common causes of normocytic anaemia?
1 - anaemia of chronic disease
2 - acute haemorrhage
3 - renal failure (no EPO for maturing of RBCs)
What is reticulocyte count a measure of?
- RBCs production in bone marrow
If a patient has lethargy and their MCV is 96fL, what are the 3 key things that we need to measure in the blood that will help identify most common causes of anaemia?
1 - WBC
2 - Platelets
3 - MCV
If someone has anaemia caused by iron deficiency, what appearance will RBCs have?
- microcytic (small - <80fL)
- pale
If someone has anaemia caused by B12 or folic acid deficiency, what appearance will RBCs have?
- macrocytic (large - >100fL)
- low WBC
- megaloblastic (affects RBC, WBCs and platelets)
What is the most common cause of anaemia in the UK?
- iron deficiency
What are the 3 most common cause of anaemia caused by iron deficiency in the UK?
- Bleeding (esp. occult = internal)
- Nutrition deficiency (vegans)
- Increased requirements (cancer)
Patients generally do not present with any signs in early iron deficiency causing anaemia, except 1 that we need to know about. What is this?
- Koilonychia (Koy-lo-nicky-e-a)
- nail koils up like in a spoon shape
If we have measured WBC, platelets and MCV, but want confirm iron deficiency, what are the 3 things we can measure in the blood to confirm iron is low?
- serum iron (floating around in circulation)
- ferritin (stored iron)
- transferrin (remember trans = transport, this is a protein that carries iron in blood)
Is measuring serum iron a reliable measure of iron deficiency alone?
- no
- could be iron from a recent meal