Haematology in GI disorders (anaemia) Flashcards
In the lab 4: 30 minutes on haematology in GI disorders -Approach to anaemia - Diagnosis of iron deficiency
What’s anaemia in terms of haem concentration in men over 15 year of age?
below 130 g/L
What’s anaemia in terms of haem concentration in non-pregnant women over 15 year of age?
below 120g/L
What’s anaemia in terms of haem concentration in children (age 12-14)?
below 120 g/L
What’s anaemia in terms of haem concentration in throughout the pregnancy?
below 110 g/L
Mean Corpuscular Volume (MCV):
what are the possibilities (result) and meaning of average volume of RBCs?
- small: microcytic anaemia
- normal: normocytic
- lage: macrocytic
Potential pitfall – remember the MCV is a mean, and doesn’t tell you everything about the RBC characteristics
Potential causes of anaemia (from the lecture slide):
- microcytic
- normocytic
- macrocytic
How to remember (my understanding):
- microcytic -> caused by deficiency/fault of something - so RBCs do not look right as do not have enough substrate to be formed
- normocytic -> blood cells may be initially formed correctly but then either destroyed or lost (e.g. haemorrhage)
- macrocytic -> blood cells cannot be formed correctly due to failure in a correct metabolic pathways (e.g. hypothyroidism)
Potential causes of anaemia (from PeerMedics):
- microcytic
- normocytic
- macrocytic
Features of RBCs on the blood smear associated with severe iron deficiency anaemia
Possible features of the anaemia found during an inspection part of GI examination
- skin and conjunctival pallor
- koilonychia
- angular stomatitis
- glossitis
- hair loss
What’s haemosiderin, haemosiderosis and haemochromatosis?
How is the iron stored within the cells?
Within the cells, iron is bound to protein and forms complexes called ferritin and haemosiderin
Haemosiderin vs Ferritin
What’s the difference?
Possible causes of iron deficiency
- chronic blood loss e.g. menorrhagia, chronic GI blood loss
- decreased iron absorption e.g. coeliac disease, atrophic gastritis, tea
- pregnancy
What’s the classic picture (on FBCs) of iron deficiency?
Microcytosis (MCV) and hypochromia (MCH)
Iron deficiency anaemia -> what occurs first: anaemia or iron deficiency?
- anaemia is a late clinical manifestation of iron deficiency
- symptoms of iron deficiency may manifest before the stage of anaemia is reached
What’s ferritin and where is it present?
- Ferritin is the main storage complex
- present mostly in the liver, but also in the bone marrow, spleen and muscles
What does serum iron measure?
Serum iron measures the amount of iron that is circulating in the liquid part of blood bound to transferrin (a transport protein).
- What do transferrin and total iron-binding capacity describe?
- What is the result of it in iron deficiency anaemia?
Transferrin and total iron-binding capacity (TIBC)
- TIBC is a reflection of how much transferrin is available to bind to iron
- In iron deficiency anaemia, the transferrin level and TIBC are high
Iron deficiency anaemia
What would be the result for:
- MCV
- Serum iron
- Serum TIBC (total iron binding capacity)
- Serum ferittin
- iron in BM
Iron deficiency anaemia
- MCV -> reduced
- Serum iron -> reduced
- Serum TIBC (total iron binding capacity) -> increased
- Serum ferittin -> reduced
- iron in BM -> absent
Anaemia of Chronic disease
What would be the result for:
- MCV
- Serum iron
- Serum TIBC (total iron binding capacity)
- Serum ferritin
- iron in BM
Anaemia of Chronic Disease
- MCV -> low or normal
- Serum iron -> reduced
- Serum TIBC (total iron binding capacity) -> reduced
- Serum ferritin -> normal or raised
- iron in BM -> present
Thalassemia
What would be the result for:
- MCV
- Serum iron
- Serum TIBC (total iron binding capacity)
- Serum ferritin
- iron in BM
Thalassemia
- MCV -> reduced
- Serum iron -> normal
- Serum TIBC (total iron binding capacity) -> normal
- Serum ferritin -> normal
- iron in BM -> present
Sideroblastic anaemia
What would be the result for:
- MCV
- Serum iron
- Serum TIBC (total iron binding capacity)
- Serum ferritin
- iron in BM
Sideroblastic anaemia
- MCV -> low (in inherited); normal (in acquired)
- Serum iron -> raised
- Serum TIBC (total iron binding capacity) -> normal
- Serum ferritin -> raised
- iron in BM -> present
Sideroblastic anemia or sideroachrestic anemia is a form of anemia in which the bone marrow produces ringed sideroblasts rather than healthy red blood cells:
- the body has iron available but cannot incorporate it into hemoglobin
- granules of iron accumulated in the mitochondria surrounding the nucleus
*it is either a genetic disorder or part of myelodysplastic syndrome (haematological malignancies)
What does hepcidin do in terms of iron concentration in the blood?
Hepcidin regulates iron homeostasis (metabolism and absorption)
Hepcidin binds to cell surface ferroprotein causes its degradation (via lysosomes)
Summary: hepcidin INHIBITS iron absorption, release and transport
How does hepcidin behave in iron deficiency?
