Aani Haem: Anaemia Flashcards
What are causes of microcytic anaemia?
Iron deficiency
Thalassaemia
ACD
Sideroblastic anaemia
What is sideroblastic anaemia?
When body cannot incorporate iron into haemoglobin - ineffective erythropoeisis
What do sideroblasts look like?
Nuceleated erythroblasts - they have iron granules around the nucleus to form ‘rings’ = Ring Sideroblasts
Where are sideroblasts normally found?
In the Bone Marrow
What will the TIBC be in iron deficiency anaemia (IDA)?
High because there is free transferrin because not enough iron to bind to it
What will the ferritin levels be in IDA?
LOW because it is a storage of iron. Not enough iron to form storage tins
Causes of IDA?
- Lack of absorption e.g. gastic surgery, coeliac.
- Too much excretion e.g. MAHA
- Little intake e.g. Babies/Old people
- Blood loss e.g. peptic ulcers, hookworm, HMB
- Higher demand e.g. kids and pregnancy
Where in sideroblasts is the iron stored?
In mitochondria around the nucleus
Which stain is used to see sideroblasts?
Prussian Blue Stain
Causes of sideroblastic anaemia?
- MDS
- Lead excess
- Chemo
- Alcohol excess
Treatment of sideroblastic anaemia?
Pyridoxine (Vit B6- promotes RBC synthesis)
What will the ferritin levels be in ACD?
High because the iron is sequestered to prevent bacteria from getting it
What will serum iron levels be in ACD?
Low, it all been sequestered
What will TIBC be in ACD?
Low
What is TIBC an indirect measure of?
Transferrin
When is TIBC low?
When the iron stores are full e.g. ACD, sideroblastic anaemia
When is TIBC high?
When the iron stores are low and empty so we need more iron e.g. IDC
How do inflammatory markers cause ACD?
IL1 and TNF reduce the EPO receptor so less EPO synthesis
IL6 and LPS make hepcidin which reduces Iron absorption from the gut by reducing Transferrin
When is Ferritin high?
It is an acute phase protein and high during infection/inflammation/ malignancy
Causes of macrocytic anaemia?
M FAT RBC Myelodysplastic Disorders Foetus Antifolates (phenytoin) /Alcohol Thyroid (hypothyroid) Reticulocytosis B12 deficiency/Folate deficiency Cirrhosis
What causes megaloblastic anaemia?
b12 and folate deficiency
What does megaloblastic film look like?
Hypersegmented neutrophils
Leukopaenia
Macrocytosis of RBCs
Anaemia
Why does B12 deficiency take less time to occur than folate deficiency?
because we have B12 stores in our liver
Where does B12 come from?
Meat & dairy
Where is B12 absorbed?
Stomach, then terminal ilium
Which cells make Intrinsic factor?
Gastric parietal cells
Which condition prevents absorption of B12?
Pernicious Anaemia (Abs against IF and parietal cells)
Which tests can test for Pernicious anaemia?
- Schillings (outdated)
- Parietal cell ABS
- Intrinsic Factor Abs
Treatment of B12 deficiency?
Replenish B12 with IM hydroxocobalamin
Where is folate absorbed?
Jejenum
Where does folate come from?
Green vegetables, nuts, yeast
Symptoms of B12/folate deficiency?
Glossitis
Angular Cheilosis
What does free plasma Hb bind to? N.B. Free plasma Hb is ABNORMAL. Hb should be contained within RBCs.
Haptoglobins
When haptoglobins run out, what happens to excess free Hb?
Filtered by glomerulus –> Haemoglobinuria (dark red/coca cola urine)
At what level of Hb do haptoglobins run out?
150 g/l
What are the consequences of free Hb?
AKI - nephrotoxic!
Haemosiderinuria
Consequences of haemolysis?
Anaemia
Excess bilirubin –> gall stones
Susceptible to parvovirus B19
Iron overload
What is the purpose of the DAT test?
Identify whether haemolytic anaemia is autoimmune or not.
Do you get free plasma Hb in extravascular haemolysis?
No. It occurs within macrophages
What is missing in paroxysmal nocturnal haemoglobinuria (PNH)?
GPI anchor that protects RBC against complement mediated destruction
Causes of extravascular haemolysis?
Autoimmune & Hereditary Spherocytosis
What is LDH?
Lactate Dehydrogenase
When is LDH released: intra or extra vascular haemolysis?
Intravascular only (it is released from cells)
Biological features of extravasc haemolysis?
- Splenomegaly
- Rise in unconj bilirubin
- Rise in urobilinogen
- High reticulocytes
- Pigmented gallstones