Iron Deficiency and Anaemia of Chronic Disease Flashcards
In what state is the iron in the haem group of haemoglobin?
Fe2+ (ferrous)
How much iron do you need per day to maintain the production of red blood cells?
How much iron does the human diet normally provide?
20 mg/day
Diet: 12-15 mg/day
How can iron be lost under normal, non-pathological conditions?
Desquamation of cells in the skin + gut
Bleeding (menstruation is 1 of the largest causes of loss of iron from the body in women)
State 4 foods that are high in iron.
Meat + fish
Vegetables
Whole grain cereal
Chocolate
Which form of iron cannot be absorbed? What effect does drinking tea have on iron absorption?
Fe3+ (ferric)
Tea promotes the conversion of Fe2+ to Fe3+
Why do meat and fish eaters have an advantage over vegetarians in terms of iron absorption?
They absorb iron in the haem form
State 3 systemic factors that increase iron absorption.
Iron deficiency
Anaemia/ hypoxia
Pregnancy
Which channel, on the basement membrane of intestinal epithelial cells, allows movement of iron into the circulation?
Ferroportin
What is a key regulator of iron absorption that affects ferroportin?
Hepcidin
How is the level of hepcidin affected?
Certain proteins (e.g. hepcidin) have iron-responsive elements in their genes So iron is part of the complex that switches on hepcidin transcription High iron = high hepcidin = low ferroportin = low absorption
How is iron stored within cells?
In ferritin micelles
What transports iron in the circulation?
Transferrin
State 3 parameters that can be measured that involve transferrin?
Transferrin
Transferrin Saturation
Total Iron Binding Capacity (TIBC)
What is the normal transferrin saturation?
20-40%
Where is erythropoietin produced and what effect does it have?
Kidneys (stimulated by hypoxia)
Increase in RBC precursors
RBC precursors will survive longer + EPO will make them grow + differentiate to produce more progeny
What is anaemia of chronic disease?
Anaemia in patients with chronic disease
What 3 typical signs of anaemia will patients with ACD NOT have?
NO bleeding
NOT iron deficient, B12 deficient or folate deficient
NO bone marrow infiltration
State 3 laboratory signs of being ill.
Raised C-reactive protein (CRP)
Raised Erythrocyte Sedimentation Rate (ESR)
Raised acute phase response proteins: Ferritin, Factor VIII, Fibrinogen,Immunoglobulins
State 4 causes of anaemia of chronic disease.
Chronic infections e.g. TB/ HIV
Chronic inflammation e.g. SLE, rheumatoid arthritis
Malignancy
Miscellaneous e.g. cardiac failure
What is the underlying cause of ACD?
ACD is due to the cytokine release that happens when someone is unwell
Cytokines block utilisation of iron by RBCs
Stop erythropoietin from increasing
Stop iron flowing from duodenum to red cells
Increase production of ferritin
Increased death of red cells
Give 2 examples of cytokines involved in ACD.
TNF- alpha
Interleukins
State 4 broad causes of iron deficiency.
Bleeding e.g. Menstrual, GI
Increased use e.g. growth, pregnancy
Dietary deficiency e.g. vegetarian
Malabsorption e.g. Coeliac disease
Under what conditions are full GI investigations performed?
When good diet with no coeliac antibodies + Male Women >40 Post-menopausal women Women with scanty menstrual loss
State 2 non-invasive investigations that can be performed for iron deficiency
Antibodies for coeliac disease
Check for urinary blood loss
State 3 causes of a low MCV.
Iron deficiency
Anaemia of chronic disease (low or normal)
Thalassemia trait
How would you confirm thalassemia trait?
Haemoglobin electrophoresis
How does serum iron help distinguish between the 3 causes of microcytic anaemia?
Iron deficiency – LOW serum iron
ACD – LOW serum iron
Thalassaemia trait- NORMAL serum iron
Describe the difference in ferritin levels in iron deficiency and anaemia of chronic disease.
Iron deficiency: LOW
ACD: HIGH (because it is an acute phase protein)
Why is ferritin not always reliable?
Some people may have a chronic disease + be bleeding e.g. RhA + a bleeding ulcer- here, ferritin may appear normal
Need to check the signs of infection/inflammation e.g. ESR + CRP to see if there is an underlying condition causing a rise in acute phase proteins
Describe the difference in transferrin in iron deficiency and ACD.
Iron deficiency: HIGH
ACD: LOW/NORMAL
Describe the difference in transferrin saturation in iron deficiency and ACD.
Iron deficiency: LOW (iron levels have decreased)
ACD: NORMAL (transferrin levels have also decreased)
State what you’d expect the following parameters to be in iron deficiency:
Hb, MCV, Serum Iron, Ferritin, Transferrin + Transferrin Saturation
Hb: LOW MCV: LOW Serum Iron: LOW Ferritin: LOW Transferrin: HIGH Transferrin Saturation: LOW
State what you’d expect the following parameters to be in anaemia of chronic disease:
Hb, MCV, Serum Iron, Ferritin, Transferrin + Transferrin Saturation
Hb: LOW MCV: LOW / NORMAL Serum Iron: LOW Ferritin: HIGH / NORMAL Transferrin: NORMAL / LOW Transferrin Saturation: NORMAL
State what you’d expect the following parameters to be in thalassemia trait:
Hb, MCV, Serum Iron, Ferritin, Transferrin + Transferrin Saturation
Hb: LOW MCV: LOW Serum Iron: NORMAL Ferritin: NORMAL Transferrin: NORMAL Transferrin Saturation: NORMAL
What are full GI investigations?
Upper GI endoscopy
Duodenal biopsy
Colonoscopy
Small bowel meal + follow through
