Anaemia Flashcards
(70 cards)
1
Q
What is an erythrocyte more commonly known as?
A
- RBC
2
Q
What is erythropoiesis?
A
- RBC production that occurs in bone marrow
3
Q
How many alpha and beta globulins are generally present in RBCs?
A
- 2 alpha
- 2 beta
- globulins are made up of 2 polypeptide chains
4
Q
How many iron and heme molecules are present in one haemoglobin molecule?
A
- 4 of each
- heme binds to globulin
- iron binds to heme (4 O2 can bind to each haemoglobulin)
5
Q
What is the iron state when O2 is and is not bound to haemoglobulin?
A
- Fe3+ when bound to O2
- Fe2+ when unbound to O2
6
Q
What is anaemia?
A
- lack of haemoglobulin in blood
- causes lack of O2 in blood
7
Q
What are the 2 most common causes of anaemia?
A
- low RBCs
- low haemoglobulin content
8
Q
What is haematocrit?
A
- ratio of the volume of red blood cells to the total volume of blood
- normal level is around 45%
9
Q
What is mean cell volume, referred to as MCV?
A
- the avaerage size of the RBCs
- normal is 80-120fL
10
Q
What is the basis upon how cell counters work?
A
- they detect change in impredance
- change is determined by the volume
11
Q
When spinning blood, what are the 3 layers at the end?
A
- RBCs at the bottom
- buffy coat in middle (platelets and WBCs)
- plasma containing proteins
12
Q
When trying to understand the cause of anaemia, what are the 4 things that need to be considered? Remember that RVCs are like money.
A
- not making enough RBCs (impaired erythropoiesis)
- spending too much RBCs (cancer)
- lost RBCs (trauma)
- hidden RBCs (bleeding internally)
13
Q
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?
A
- microcytic = small (<75fl)
- macrocytic = large (>96fl)
- normacytic = 80-96fL
14
Q
What is generally the cause of microcytic anaemia?
A
- haemoglobin problems
- iron deficiency (need more iron molecules)
- inherited disorders (thalassaemia - globulin molecules not made)
15
Q
What is the most common cause of microcytic anaemia worldwide?
A
- iron deficiency
16
Q
What are the common causes of macrocytic anaemia?
A
- B12 deficiency (cobalamin)
- folic acid deficiency (B9)
17
Q
Why do B12 (cobalamin) and/or folic acid cause macrolytic anaemia?
A
- both are needed to make DNA
- RBCs are enlarged due to defects in synthesis
18
Q
Myelodysplasia is a cause of macrocytic anaemia. What is this?
A
- abnormal RBCs due to ageing or genetic mutations
- DNA is unable to make RBCs
19
Q
What are the 3 most common causes of normocytic anaemia?
A
1 - anaemia of chronic disease
2 - acute haemorrhage
3 - renal failure (no EPO for maturing of RBCs)
20
Q
What is reticulocyte count a measure of?
A
- RBCs production in bone marrow
21
Q
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?
A
1 - WBC
2 - Platelets
3 - MCV
22
Q
If someone has anaemia caused by iron deficiency, what appearance will RBCs have?
A
- microcytic (small - <80fL)
- pale
23
Q
If someone has anaemia caused by B12 or folic acid deficiency, what appearance will RBCs have?
A
- macrocytic (large - >100fL)
- low WBC
- megaloblastic (affects RBC, WBCs and platelets)
24
Q
What is the most common cause of anaemia in the UK?
A
- iron deficiency
25
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)
26
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
27
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)
28
Is measuring serum iron a reliable measure of iron deficiency alone?
- no
- could be iron from a recent meal
29
Is measuring ferritin (stored iron) a reliable measure of iron deficiency alone?
- a good measure
- low = deficient
- high = overload
30
Is measuring serum transferrin (transporter of iron), also known as total iron binding capacity a reliable measure of iron deficiency?
- yes
- increases when serum iron is low to scavenage for iron
31
What is the most sensitive measure of iron deficiency?
- transferrin saturation
- ratio between serum iron and transferrin (transports iron)
- if low = iron deficient
32
What is occult GI malignancy in relation to anaemia?
- blood that leaks into the GI tract causing anaemia
33
What common event each month can make women more susceptible to anaemia?
- menstrul cycle
34
If you suspect a patient is aneamic and you have already looked at the WBC, MCV and platlet count, what are 3 blood markers that should be measured?
1 - serum iron
2 - folate
3 - B12 (cobalamin)
35
What is folate deficiency?
- reduced folage (vegetable) cuasing low folic acid
- folic acid is also called B9
- folice acid makes RNA and DNA
36
What are 2 common gastrointestinal diseases that can cause folate deficiency due to malabsorptin?
1 - coeliacs disease in upper GI (gluten intolerance)
2 - crohns disease (inflammatory bowel disease)
37
What form of anaemia is folate deficiency able to cause?
- macrocytic anaemia
- blood cells unable to maturate into reticulocytes due to DNA
38
What is vitamin B12, also known as cobalamin and why is it important in anaemia?
- vitamin in meat and dairy
- coenzyme in DNA and RNA synthesis
39
How is vitamin B12, also known as cobalamin absorbed in the diet?
- digested in stomach
- intrinsic factor (IF) released from parietal cells and bind to B12
- B12 bound to IF is absordbed in ileum broken down and absorbed
40
Pernicious means to have a harmful effect on something. What is pernicious anaemia?
- immune system attacks parietal cells so no IF
- no IF means no B12
- can be treated with B12 injections
41
What is megaloblastic anaemia?
- large RBCs caused by B12 or B9 deficiency
42
How long can it take the human body to become deficient in:
- iron
- vitamin B12
- folic acid
- iron = 6-8 years
- vitamin B12 - 3-4 years
- folic acid - 4 months
43
What is anaemia of chronic disease?
- anaemia caused by a chronic condition
- most common cause of anaemia in hospitalised patients
44
In chronic disease what can cause increased use of iron?
- inflammation
45
In chronic disease what are some of the common causes of the anaemia?
- inflammation (autoimmune)
- cancer
- renal failure (low EPO)
46
In iron deficiency and chronic disease anaemia is serum iron low in both?
- yes
47
In iron deficiency and chronic disease anaemia is ferritin low in both?
- no
- iron deficiency = yes
- chronic disease anaemia = normal or high
48
In iron deficiency and chronic disease anaemia is transferris low in both?
- no
- iron deficiency = high
- chronic disease anaemia = low as none available
49
In iron deficiency and chronic disease anaemia is transferrin saturation low in both?
- no
- iron deficiency = low
- chronic disease anaemia = normal
50
In chronic disease ferritin is available in stores such as in the liver, so why do they develop anaemia?
- unable to mobilise
- iron stuck in macrophages in bone marrow
51
What is normocytic anaemia?
- Mean corpuscular volume (MCV) appears normal
- BUT large SD of micro and macrocytic RBCs
52
What is the the cause of normocytic anaemia?
- combination of iron, B12 and/or B9 deficiency
53
In additon to iron, B12 and B9 deficiencies, what else related to RBC production could cause normocytic anaemia?
- chronic kidney disease
- kidneys produce erythropoeitin (EPO) for RBC maturation
- chronic diseases
54
If the MCVs, iron, B12 and B9 are all normal with no chronic disease inflammatory disease or malignancy, what would be the test that could be performed to try and identify the cause of the anaemia?
- bone marrow biopsy from iliac crest
- blood cell factory
55
If a patient is having a biopsy as their iron, B12 and B9 are normal, what would be low in the blood sample?
- reticulocyte count is low
56
What are the 3 most common causes of bone marrow failure?
1 - myelodysplasia (RBCs do not mature - genetic or cancerous)
2 - marrow is full (leukaemia, lymphoma, myeloma)
3 - marrow is empty (aplastic anaemia)
57
RBCs generally last between 100-120 days and are the broken down and recycled. However, there are some conditions that can reduce the life of a RBC, which is called haemolysis. What are the 3 most common inherited conditions?
1 - membrane problems
2 - haemoglobin problems
3 - metabolic problems
58
Problems with the RBCs membrane can shorten the life span of RBCs. What are the most common causes of inherited membrane dysfunction of RBCs?
- sickle cell disease changes membrane shape
- thalassaemia
59
What is sickle cell disease?
- an autosomal recessive disease (both parents need to pass on gene)
- no alpha haemoglobin, swapped with s haemoglobin
- common in Africa and South America (malaria protection)
- circle appears on blood stain within RBC
60
In sickle cell disease, what happens if you have both genes for S haemoglobin and 1 S haemoglobin?
- 1 sickle and 1 alpha haemoglobin = sickle cell trait
- 2 sickle cell haemoglobin = sickle cell disease
61
Although microcytic anaemia is more commonly caused by iron deficiency, it can also be inherited in a disease called thalassaemia, what is this disease?
- thalassa is greek for by the sea, as first identified here
- anaemia means low haemoglobin
- genetic mutation in alpha or beta globins
62
In thalassaemia, what happens to the globins?
- they may not be produced at all
- they may be dysfunctional, so heme and iron cannot bind
63
In thalassaemia the iron will appear normal, so how can these patients be diagnosed?
- haemoglobin electrophoresis
64
Generally where is thalassaemia more common?
- similar areas as malaria
65
What is glucose 6 phosphate dehydrogenase (G6PD)?
- an enzyme
- it protects RBCs from oxidation
- without it RBCs undergo haemolysis
66
Immune haemolytic anaemia is caused when the immune system attacks its own RBCs. There are 2 forms of Immune haemolytic anaemia called warm IgG and cold IgM, what are these?
- in warm IgG, IgG attack RBCs when the body is warm
- in cold IgM, IgM attack RBCs when the body is cold
- both cause low RBCs and low haemoglobin and therefore anaemia
67
If MCV, WBC and platelets are normal, and then iron, B12 and B9 are all normal, what could be a cause of anaemia?
- bleeding disorders
- blood leaks in GI tract (occult)
- internal bleeding
68
Bleeding can cause anaemia, in a very acute bleed/loss of blood. During this will haemoglobin and MCV be normal or low?
- both will be normal
69
Bleeding can cause anaemia, in chronic bleeding/loss of blood. During this will haemoglobin and MCV be normal or low?
- haemoglobin will be low
- MCV will be microcytic as iron will be low
70
What are the 3 most common causes of bleeding that can cause anaemia, that can be acute or chronic?
1 - menstrul cycle
2 - GI tract
3 - urinary
