DUMS Flashcards
what is a haem group
iron and flat porphyrin ring
erythropoiesis
production of RBCs
where are iron stores
liver, spleen, bone marrow
how are red cells produced in hypoxia
hypoxia sensed by kidneys > EPO produced which stimulates red cell production
site of haematopoeisis
Embryo – yolk sac (week 3 -7) then liver (week 6) then marrow (week 16)
At birth – mostly bone marrow, liver and spleen
Birth to maturity – number of active bone marrow sites decreases
Adult – skull, ribs, sternum, pelvis, proximal ends of femur (axial skeleton)
monocyte
large single nucleus
faintly saining granules
becomes macrophage
what does an eosinophil look like
bi-lobed nucleus
bright orange/red granules
what does a neutrophil look like
segmented nucleus
neutral staining granules
(acute inflammation)
basophil
large deep purple granules obscuring nucleus
normal haemoglobin
males: 130–180 g/L
females: 120–160 g/L
when could you see target cells in blood film
iron deficiency anaemia
hyposplenism
thalassaemia
sickle cell
liver disease
causes of microcytic anaemia
TAILS
thalassaemia
anaemia of chronic disease
iron deficiency
lead poisoning
sideroblastic anaemia
why does microcytic anaemia happen
because you are missing the building blocks to make Hb
however the nuclear machinery still works so the cell is still dividing but the it produces smaller cells (and paler)
types of haem deficiency
lack of iron erythropoiesis
- iron deficiency
- anaemia of chronic disease
problems with porphyrin ring synthesis
- lead poisoning
- congenital sideroblastic anaemia (X-linked)
globin deficiency
- thalassaemia
transferrin
transfer iron
ferritin
stores iron
low ferritin
suggest iron deficiency
causes of iron deficiency
loss of iron (blood loss: menorrhagia, GI tumour, ulcers, NSAIDs)
malabsorption: coeliac or crohns
lack in diet
where is iron absorbed
proximal small bowel (duodenum and proximal jejunum)
what control iron absorption
hepcidin (produced in the liver)
causes of true macrocytic anaemia
megaloblastic (impaired DNA) or non-megaloblastic
what does a megaloblastic red blood cell look like
larger than normal RC precursor with immature nucleus
causes of megaloblastic
B12 deficiency
folate deficiency
how does megaloblastic anaemia happen
DNA damage affects cells ability to divide
Hb production carries on as normal
where do you get B12 and how long can you store it
animal products
stores for 2-4 years
causes of B12 deficiency
low dietary intake
pernicious anaemia
gastrectomy and congenital def of intrinsic factor
what is pernicious anaemia
autoimmune condition
causing destruction of gastric parietal cells
resulting in intrinsic factor deficiency with B12 malabsorption in the ileum
why can pernicious anaemia patients appear mildly jaundiced
intramedullary haemolysis
testing for pernicious anaemia
auto-antibodies
- intrinsic factor antibody (first line)
- gastric parietal cell antibody
presentation of pernicious
peripheral neuropathy with numbness or paraesthesia
loss of vibration or proprioception
visual changes
mood or cognitive changes
management of pernicious anaemia
1Mg hydroxocobalamin 3x a week then every 3 months
what food contains folate and where is it absorbed
found in plant food and absorbed in jejunum
causes of folate deficiency
diet (alcoholics)
malabsorption (coeliac, crohns)
excess utilisation- pregnancy, malignancy, exfoliating dermatitis, haemolysis
drugs (anticonvulsants)
causes of non-megaloblastic macrocytosis
alcohol excess
liver disease
hypothyroidism (may not be associated with anaemia)
marrow failure (myelodysplasia, myeloma, anaplastic anaemia)
indications for a blood transfusion
symptomatic anaemia where Hb <70
examples of false macrocytosis
reticulocytosis in response to acute blood loss or red cell breakdown- reticulocytes are bigger than mature red cells
cold-agglutinins- cause RBCs to clump at temperatures lower than core body temp
