Haem I (Anaemia) Flashcards
What is a single test that would reveal a patient is suffering from an autoimmune haemolytic anaemia? [1]
Direct positive coombs test
Describe the lineage of multipotent myeloid stem cells [4]
What is TPO? [1]
Where is it produced? [1]
What does it regulate ? [1]
Thrombopoietin (TPO):
TPO is produced by the liver and essential for the control of platelet production
What is the pathway from Haematopoietic stem cell (HPSCs) - to erythrocyte? [1]
Haematopoietic stem cell (HPSCs)
–>
common myeloid progenitor cell (CMPC)
–>
Proerythroblast
–>
erythroblast
–>
reticulocyte
–>
erythrocyte
The proerythroblast develops into an (early) erythroblast. The erythroblast then undergoes a sequence of changes where its nucleus progressively shrinks and its cytoplasm becomes filled with haemoglobin (not stained). When full of haemoglobin it is called a normoblast. The normoblast then expels its nucleus and becomes a reticulocyte. Most reticulocytes stay in the marrow and mature into erythrocytes but some may be released into the blood, especially after haemorrhage. Reticulocytes can transport oxygen, just not as efficiently as mature erythrocytes. They can mature into adult RBCs in the circulation
Include iron stuff.
Name 5 drugs which cause macrocytic anaemia?
Azathioprine
Methotrexate
Fluorouracil
Phenobarbital
Mercaptopurine
Trimethoprim
What are specific signs associated with anaemia of iron deficiency? [4]
- Koilonychia (spoon shaped nails)
- Angular stomatitis (inflammation of corners of mouth)
- Restless legs syndrome
- Hair loss
- Post-cricoid webs
Name 7 risk factors for IDA
- pregnancy
- vegetarian and vegan diet
- menorrhagia
- hookworm infestation
- chronic kidney disease
- coeliac disease
- gastrectomy/achlorhydria
- non-steroidal anti-inflammatory drug (NSAID) use
- chronic heart failure
Why do PPIs interfere with Fe absorption? [1]
Fe is best absorbed in an acidic environment
Proton pump inhibitors (e.g., omeprazole), can interfere with iron absorption as they reduce stomach acid
Describe what is meant by transferrin saturation [1]
What is the formula for transferrin saturation? [1]
Transferrin saturation refers to the proportion of the transferrin molecules bound to iron, expressed as a percentage.
Transferrin saturation = serum iron / total iron-binding capacity
What do raised ferritin levels indicate? [4]
Inflammation (e.g., infection or cancer)
Liver disease
Iron supplements
Haemochromatosis
A patient presents with IDA without a clear underlying cause. What is the next stage in investigating this patient? [2]
colonoscopy and oesophagogastroduodenoscopy (OGD) for malignancy.
Describe the management of IDA [3]
1ST LINE
- oral iron replacement (ferrous sulfate)
- 200 mg once daily
2ND LINE
- intravenous iron replacement
3rd LINE:
- Blood transfusion
Describe what would describe to a patient about taking oral iron [2]
Oral iron works slowly. A rise in haemoglobin of 20 grams/litre is expected in the first month.
Common side effects are constipation, naseua, **abdominal pain & **black stools.
Describe the pathophysiology of ACD [2]
Hepcidin is acute phase protein that usually works to reduce the availability of iron from infecting microorganisms.
Chronic inflammation mediated by IL-6 can lead to a hepcidin-induced block of iron absorption and iron release from macrophages
This reduction in the availability of iron for the production of erythrocytes as part of erythropoiesis can lead to a microcytic anaemia. However, this is only seen in 25% of cases.
Describe the FBC result for ACD [2]
The FBC may show a normocytic normochromic anaemia (approx. 75%)
or
a microcytic anaemia (approx. 25%).
In ACD, the MCV is rarely below 70 fL.
Describe how Fe tests would help to diagnose ACD [3]
The clinical presentation of ACD is generally that of the underlying disorder
Serum ferritin:
- Normal or raised (due to release during inflammation)
Serum iron:
- Low
TIBC:
- Low
What are specific signs associated with anaemia of vit. B12 deficiency? [7]
- Glossitis
- Positive Rombergs test & neurological impairment - posterior column degeneration
- Decreased vibration sense - posterior column degeneration
- Ataxia - posterior column degeneration
- Hyperpigmentation of nails
- Petechiae: generally a late sign of vitamin B12 deficiency.
- Optic neuropathy
Define what is meant by pernicious anaemia [2]
Pernicious anaemia is an autoimmune condition involving antibodies against the parietal cells or intrinsic factor. Intrinsic factor is essential for B12 absoprtion
Specifically have:
- Antibodies to intrinsic factor: block vitamin B12 binding site
- Antibodies to gastric parietal cells: reduced acid production and atrophic gastritis. Therefore less B12 absorption
Describe the clinical features of pernicious anaemia
Peripheral neuropathy, with numbness or paraesthesia (pins and needles)
mild jaundice: combined with pallor results in a ‘lemon tinge’
Loss of vibration sense
Loss of proprioception
Visual changes
Mood and cognitive changes
TOM TIP: For your exams, remember to test for vitamin B12 deficiency and pernicious anaemia in patients presenting with []
TOM TIP: For your exams, remember to test for vitamin B12 deficiency and pernicious anaemia in patients presenting with peripheral neuropathy, particularly with pins and needles.
Describe the treatment regime for pernicious anaemia
Intramuscular hydroxocobalamin is initially given to all patients with B12 deficiency, depending on symptoms:
No neurological symptoms
- 3 times weekly for two weeks
Neurological symptoms
- alternate days until there is no further improvement in symptoms
MAINTENANCE:
Pernicious anaemia
– 2-3 monthly injections for life of intramuscular hydroxocobalamin
Diet-related:
- oral cyanocobalamin or twice-yearly injections
Describe the presentation of subacute combined degeneration of the spinal cord [3]
progressive weakness
ataxia
paresthesias that may progress to spasticity and paraplegia
Which vitamin is folate? [1]
B9
Describe causes of folate deficiency [6]
- Inadequate dietary intake
- Alcohol excess
- Malabsorption (e.g. coeliac disease, Crohn’s disease)
- Increased requirements (e.g. pregnancy, malignancy)
- Increased loss (e.g. Chronic liver disease)
- Other (e.g. anti-convulsants, ETOH abuse)
Which investigations are used to diagnose folate deficiency? [1]
Red cell folate is a better measure of levels than serum folate, since levels are affected even with a short period of deficiency.
How do you treat folate deficiency? [1]
Folic acid is usually given as a once daily oral dose of 5 mg for up to four months.
[] is the most common cause of a non-megaloblastic anaemia
Explain your answer [1]
Chronic alcohol use is the most common cause of a non-megaloblastic anaemia.
It is thought to be due to the toxic effects of acetaldehyde on erythrocyte progenitors.
What advice should you give pregnant women regarding folic acid intake? [1]
Folate deficiency causes an increased risk of which pathology? [1]
all women should take 400mcg of folic acid until the 12th week of pregnancy
Risk of neural tube defects
Which heridatory diseases fall under umbrella of haemolytic anaemia? [5]
- Hereditary spherocytosis
- Hereditary elliptocytosis
- Thalassaemia
- Sickle cell anaemia
- G6PD deficiency
What are the key investigation results for haemolytic anaemia? [3]
Full blood count shows a normocytic anaemia
Blood film shows
schistocytes (fragments of red blood cells)
Direct Coombs test is positive in autoimmune haemolytic anaemia (not in other types)
Define what is meant by: [3]
- Hereditary spherocytosis
- Hereditary elliptocytosis
Hereditary spherocytosis
- Autosomal dominant familial condition; autoantibodies produced against proteins in RBC membrane mean it causes a spherical shape when they pass through the spleen
- Can still perform adequately despite reduced SA
- Fragile and easily lysed
Hereditary elliptocytosis:
- Autosomal dominant familial condition; autoantibodies produced against proteins in RBC membrane mean it causes an ellipse shape
- Can still perform adequately despite reduced SA
- Fragile and easily lysed
Mycoplasma pneumoniae
specific features of autoimmune haemolytic anaemia: positive direct antiglobulin test (Coombs’ test).
SCA
Hyposplenism
Hyposplenism
Hyposplenism
Hyposplenism
Describe the clinical presentation of a vaso-occlusive crisis in SCA [3]
(Which bones are more commonly impacted?)
Vaso-occlusive crises:
- Acute pain in the hand and feet (dactylitis) owing to vasoocclusion of the small vessels and avascular necrosis of the bone
marrow in children
- Possible to have CNS infarction in children leading to stroke,
seizures and cognitive defects
- In adults there is pain in the long bones such as the femur, spine, ribs and pelvis due to avascular necrosis of the bone marrow
How does an acute chest syndrome present on CXR? [1]
Pulmonary infiltrates
According to NICE guidelines, which laboratory test is considered the gold standard for confirming the diagnosis of sickle cell anemia?
a) Complete Blood Count (CBC)
b) Hemoglobin Electrophoresis
c) Serum Ferritin
d) Coagulation Profile
According to NICE guidelines, which laboratory test is considered the gold standard for confirming the diagnosis of sickle cell anemia?
a) Complete Blood Count (CBC)
b) Hemoglobin Electrophoresis
c) Serum Ferritin
d) Coagulation Profile
