Pernicious anaemia Flashcards
what type of disease in pernicious anaemia?
autoimmune disorder
which vitamin is affected pernicious anaemia?
what happens to this vitamin’s levels?
vitamin B12
low
Define pernicious?
causing harm in a subtle or gradual way
why is diagnosis oft delayed?
because symptoms are subtle
Normal take up of Vit B12?
step by step
- Stomach’s parietal cells makes intrinsic factor
- Intrinsic factor binds to vit B12
- Vitamin B12-intrisnic factor is absorbed at the terminal ileum via a Ca2+ dependent process
- Enterocytes will bind vit B12 to transcobalamin II (a transport protein)
- Now B12 can move through blood.
where is intrinsic factor made?
Stomach
function of intrinsic factor?
bind to vit B12
which cells make intrinsic factor?
where are these cells located?
parietal cells
stomach
B12 is absorbed where?
which mineral is involved in the absorption here?
terminal ileum
Ca2+ (helps absorb vit B12)
vit B12 is bound to which transport protein so it can be carried in the blood?
where does this binding happen?
transcobalamin II
ileum
vitamin B12’s normal functions?
-2
make blood cells
myelinate nerves
in Pernicious anaemia, why does vit B12 absorption decrease?
-2 ways
o Intrinsic factor antibodies bind to intrinsic factor - this blocks vit B12’s binding site
o gastric parietal cell antibodies cause atrophic gastritis – thus intrinsic factor not made – less B12 absorbed
↓Vit B12 will cause what disorders generally speaking?
-2
macrocytic anaemia & neuropathy
which gender is a risk factor?
Females
which blood group is a risk factor?
Blood Group A
Risk Factors?
-4
Females
Middle to old age
Other autoimmune disorders
Blood Group A
which cancer is a potential complication in pernicious anaemia?
Gastric Cancer
Anaemia symptoms in pernicious anaemia?
Lethargy
Pallor
Dyspnoea
neuro symptoms in pernicious anaemia can be split into what 3 categories?
Peripheral neuropathy features
Spinal cord degeneration
Neuropsychiatric features
vit B12 deficiency signs at the mouth
-2
Glossitis – red tongue
central cyanosis
skin colour in pernicious anaemia?
why does this happen?
lemon tinge
pallor from anaemia + mild jaundice
Neuropsychiatric symptoms?
-5
Memory loss Poor focus Confusion Depression Irritability
Spinal cord degeneration symptoms?
-4
Progressive weakness
Ataxia
Spasticity
Paraplegia
Peripheral neuropathy symptoms?
-3
which limbs are affected more?
Pins & needles
Numbness
Paraesthesia
legs more than arms
define paraplegia?
paralysis of the legs
define hemiplegia?
paralysis of one side of the body
define ataxia?
inability to coordinate voluntary muscular movement due to a CNS disorder
main Ix?
-4
results for each.
FBC: macrocytic anaemia, low WBC, low platelets
↓Vit B12
↓intrinsic factor
Antibodies: anti intrinsic factor antibodies & anti gastric parietal cell antibodies present
what happens to platelets and WBC?
give the medical name
leukopenia
thrombocytopenia
what happens to MCV?
high
what does MCV stand for?
mean corpuscular volume
1st line Mx?
-route
how much do you give?
Vitamin B12 IM injection
6 injections over 2 weeks, then 3 injections a month
how do you change Mx if there are neuro symptoms?
Give more B12 if neuro symptoms present
some pts will require what other supplement?
folic acid supplement
