M103 T2 Symposia Flashcards
What are the two main causes of microcytic anaemia?
Fe deficiency – acquired
Thalassaemia – inherited
What causes acquired microcytic anaemia?
Chronic bleeding (GI tract, Menstrual)
Low ferritin
Low Fe, high transferrin, low transferrin saturation
What causes inherited microcytic anaemia?
alpha, beta (quantitative 𝛼/𝛽 imbalance)
normal ferritin, abnormal Hb electrophoresis/HPLC
What are the three main causes of macrocytic anaemia?
Lack of B12 (dairy) or folate (fruit/veg)
B12 deficiency – autoimmune pernicious anaemia
Folate deficiency – many causes
What can cause autoimmune pernicious anaemia?
B12 deficiency due to lack of intrinsic factor – inadequate absorption Other causes (vegan, gastric surgery, Crohn’s)
What are some of the causes of a folate deficiency?
dietary lack (tea and toast diet); alcohol malabsorption (coeliac); excess utilisation; pregnancy
What are the two main causes of normocytic anaemia?
Anaemia of chronic disease
Renal failure
What feature of a blood sample indicates normocytic anaemia as opposed to any other anaemia?
the presence of normal-sized red blood cells
What are some of the causes of anaemia of chronic disease?
Iron trapped inside macrophages
Cancer, inflammation, rheumatoid arthritis
Normal/raised ferritin, normal/low transferrin
Raised hepcidin (and inflammatory proteins)
What are some of the causes of renal failure leading to normocytic anaemia?
Lack of erythropoietin (low serum Epo level)
Red cell hormone produced by kidney
How is renal failure that has lead to normocytic anaemia treated?
with recombinant erythropoietin (weekly sc injection)
What are the two types of bone marrow failure?
congenital
acquired
What causes acquired bone marrow failure?
Marrow is empty (aplastic anaemia)
Marrow is full (infiltration e.g. leukaemia)
Marrow is not working (e.g. dysplasia)
What are the main features of bone marrow failure?
Not making enough red cells
Reticulocyte count is low
Haematinics are normal
What is excess consumption mainly caused by?
haemolysis - inherited or aquired
What is the function of a bone marrow biopsy?
shows all precursor cells
will diagnose patients with bone marrow failure conditions
What causes acquired haemolysis?
Immune (antibodies)
Non-immune (direct damage)
What causes inherited haemolysis?
Membrane problems
Haemoglobin problems
Metabolic problems
What are the three main causes of inherited RBC problems?
Membrane problems
Haemoglobinopathy
Metabolic
What causes the membrane problems that lead to inherited RBC problems?
Red cells are spherical, not biconcave
Splenectomy can help (may need cholecystectomy for gallstones also)
What are two examples of haemoglobinopathy that lead to inherited RBC problems?
sickle cell disease (wrong type of Hb)
thalassaemia (not enough Hb)