anaemia Flashcards
define anaemia
low level of haemoglobin - result of underlying disease
what can cause microcytic anaemia?
TAILS
thalassaemia
anaemia of chronic disease
iron deficiency
led poisoning
sideroblastic
what is sideroblastic anamaeia?
has enough iron but can not put the iron into haemoglobin
defective protoporphyrin and prevents formation of haem
how do you manage microcytic anaemia?
vit C supplement and iron supplements
treat underlying cause
what can cause normocytic anaemia?
3As and 2Hs
acute blood loss, anaemia of chronic disease, aplastic anaemia
haemolytic anaemia, hypothyroidism
what is aplastic anaemia?
stops producing enough new RBC
how do you manage normocytic anaemia?
controlling blood loss, treat underlying disease, blood tranfusion, medication to promote RBC production
what can cause macrocytic anaemia?
megaloblastic - B12/ folate deficiency
normoblastic - alcohol, reticulocytosis, hypothyroidism, liver disease, drugs
how do you manage macrocytic anaemia?
B12 before folate!
targeting underlying cause, encourage diets with rich in folate (fortified cereals, leafy veg)
why do you treat B12 before folate deficiencies?
B12 deficiency can sub acute degeneration of spinal cord
folate can mask B12 deficiency
treat B12 first as a precaution
what are the general symptoms of anaemia?
tiredness, SoB, headaches, dizziness, palpitation worsening of other conditions - angina, HF, peripheral vascular disease
what are specific symptoms of iron deficiency anaemia?
pica (dietary cravings for abnormal things eg dirt)
hair loss
koilonychia - spoon shaped nails
angular chelitis - red and swollen around edge of lips
atrophic glottitis - red swollen smooth tongue
brittle hair and nails
what does jaundice in the eyes indicate?
haemolytic anaemia - build up of bilirubin
what would bone deformities with general anaemia symptoms indicate?
thalassaemia due to bone marrow expansion
how many blood groups are there?
38
which are the most significant blood groups and why?
ABO and Rh - due to being the most immunogenic
what is the ABO system based off?
- ABO system is based of presence/ absence of inherited ABO oligosaccharide antigens on the surface of patients erythrocytes as well as presence of the opposite AVO-related antibodies within patients serum
how can you be group A blood type?
AO or AA
O is recessive
how can you group AB blood group?
ab alleles - they are codominant
how can you be group O?
oo - recessive alleles
what is the rhesus system compromised of?
- Compromised of over 50 different antigens but most significant is D antigen – most immunogenic and defined by positive (presence) or negative (absence)
how are anti-D AB generated?
through exposure to Rh - D proteins
in positive cases
what is alloimmunisation?
process of being exposed to foreign antigen then produces the specific AB required
what % of blood transfusions result in alloimmunisations?
1%
what Rh group of women are risk during pregnancy?
Rh- negative if baby is potentially positive
baby’s Ig can can cross placenta and get into mothers bloodstream - mothers immune system recognises the foreign antigens and produces antibodies to fight it
if mothers (Rh - negative) AB attack foetus (Rh - pos) what can occur?
haemolytic disease of the foetus or newborn
how does HDFN present?
asymptomatic to jaundice to life threatening
what is done to prevent HDFN?
prophylaxis anti- D to Rh-neg mothers and then testing umbilical cord to determine the severity to work out how much anti-D is required in future pregnancies
what can happen with an incompatible blood tranfusion?
shock, kidney failure, circulatory collapse, death
what happens during a blood cross match?
find out ABO and Rh group
checks for other AB within receipts serum
what is the universal donor?
O neg
what is a haemolytic transfusion reaction?
destruction of incompatible donor RBC cells - can be acute or delayed response
what is a febrile non haemolytic reaction?
destruction of incompatible donor WBC
what can destruction of incompatible donor platelets cause?
post transfusion purpura - leaky capillaries under the skin
what is leukodepeltion?
all leukocytes are removed from blood - removes risk of infection or reaction to different antigens
describe acute haemolytic transfusion reaction
<24hrs
can occur during transfusion
impending feeling of doom, burning sensation at site, chills, fever, back pain
what is the most severe haemolytic transfusion reaction?
intravascular haemolysis - within blood vessels
activates complement, lyses donor RBC, haemoglobin released into plasma, bilirubin also released
what can haemolytic transfusion reaction trigger?
massive complement activation from RBC lysis - uncontrollable clotting cascade then triggers disseminated intravascular coagulation - DIC
what is most common cause of intravascular haemolytic reaction?
incompatible ABO
can transfusion result in extravascular haemolysis?
yes - donor RBC removed by macrophages within spleen and liver
donor RBC may be covered in macrophages by recipient AB
when would delayed haemolytic transfusion present?
1-14 days post transfusion
can patients have allergic reactions to blood transfusions?
yes - heightened IgE response
feeling ithcy and breaking out in hives
stop transfusion and antihistamines
can you have a transfused iron overload?
yes - numerous blood transfusions
what does excess iron do?
deposit in organs - causing damage
leads to fibrosis, cirrhosis
what diagnostic signs are seen in chronic disease anaemia?
high or normal ferritin stores
iron conc is decreases - distrupted to other areas
inflam response markers
what diagnostic signs are seen in IDA?
- Microcytic
- Increase TIBC – total iron binding capacity – how much transferrin is bound to iron
- Decrease in ferritin – more sensitive – no stores left
- Then iron conc will decrease as a result
- Check B12 and folate to rule other causes
what are IDA specific symptoms?
- Koiloncyhia: spoon shaped nails. Quite brittle
- Atrophic glossitis – inflammation of tongue, smooth and swollen
- Angular chelitis – red swollen patches on lip edges
- Post-cricoid webs (plummer vinson syndrome) – thin membranes causing dysphagia
what would IDA blood film look like?
- Microcytic anaemia and hypochromic (pale due to lack of iron which is red)
- Can be varying sizes (anisocytosis) as well as abnormal shapes (poikilocytosis)
what are the IDA investigations?
- All patients require a coeliac serology testing
- All men and post-menopausal women should have urgent upper and lower GI endoscopy unless other obvious blood loss
- Small bowel investigtaions only required if – suspect pathology or ID refractory to treatment
what is haemolytic anaemia?
premature RBC lysis
when does haemolysis of RBC occur (in terms of days)?
40days into life cycle
why does haemolysis occur?
- RBC recognised by lympho-reticulum system as abnormal
- They are not abnormal they are recognising self antigens
what are haemolytic diagnostic signs?
- High bilirubin levels
- Very high LDH – lactate dehydrogenase hormone – RBC breakdown increased (also seen in cells with high turnover – high in tumours)
- Increases reticulocyte count – immature RBC. They are rounder and smaller and contain DNA fragments so stain blue on blood films
what would indicate intra-vascular haemolysis?
- Increased methaemalbuminaemia – this binds to albumin – albumin released in breakdown
- Heamosiderinuria – excessive free Hb is filtered by renal glomeruli
what are acquired causes of haemolytic anaemia?
immune mediated seen on direct antiglobulin test positive – drug induced, autoimmune haemolytic anaemia, paroxoysmal cold haemogloburia (donath-landsteriner AB bind to RBC during cold) – (AB bind self AG during cold can have warm version
what are hereditary causes of haemolytic anaemia?
G6PD deficiency
pyruvate kinase deficiency
membrane defects
why does G6PD deficiency cause haemolytic anaemia?
puts RBC at risk of oxidative damage
what would indiciate haemolytic anaemia on a blood film?
heinz bodies and blister cells
different shape - spherocytosis or elliposis
loss of central palor - not biconcave
what membrane defects can cause haemolysis and why?
spherocytosis - loose part of cell as pass through spleen
elliptocytosis
what haemoglobinopathies can cause anaemia?
sickle cell anaemia and thalassaemia
what is produced in sickle cell anaemia?
HbS rather than HbA
why does HbS cause sickle cell anaemia?
HbS tend to polymerise - all proteins bind together and lose biconcave shape - get stuck in small vessels
what symptoms specific to sickle cell?
vaso-occlusie crisis- can lead to ischaemia, severe bone bone, dacyltitis 9severe swelling of hands and feet), leg ulcers, abdo pain, stroke/ seizures, cognitive impairment. Priapism
what are sickle cell complications?
: engorged spleen – blood gets stuck. In children can lead to atrophic spleen. Aplastic crisis: due to parovirus B19 – sudden reduction in marrow cells
- Splenic infarction ( more at risk of infections especially encapsulated organisms), poor growth, chronic renal failure, gall stones (more bilirubin production), iron overload or blood borne infections due to more blood transfusions
what is the most common cause of IDA in adults?
blood loss
who is most at risk of IDA?
pregnancy, menorrhagia, vegetarian/ vegan, coeliac disease, hookworm infection, NSAID use
what dietary products contain iron?
animal products- eggs, red meat, fish, poultry
what is he difference between folate and B12?
they are both vit B - have different sources - slightly different roles
what dietary products contain folate?
green leafy veg, citrus fruits, fruit, dry beans, peas, liver, yeast
what type of anaemia can vit b12 deficiency cause?
pernicious anaemia
what is the pathophysiology responsible for b12 deficient anaemia?
parietal cells of stomach produce intrinsic factor- essential for B12 absobrtion in the ileum
pernicious anaemia is auto-immune where AB form against parietal cells/ intrinsic factor
B12 is required for the production of RBC
what are b12 deficient specific symptoms?
neurological
visual/ mood/ cognitive changes
numbness/ paraesthesia
loss of vibration sense or proprioception
what is paraesthesia?
pins and needles sensation - seen in b12 deficiency
why are IDA usually asymptomatic or may only have fatigue?
body can try and compensate - if healthy usually can
what diseases can cause dysphagia which results in anaemia?
oesophageal malignancy, oesophageal webs (thinning membranes)
what pathologies causing dyspepsia can cause anaemia?
gastric cancer, peptic ulcer
what underlying anaemia causing pathology may present as abdo pain?
coeliac pain, intra abdo malignancy
weight loss and anaemia may indicate?
IBS, bowel cancer
which blood cells does acute leukaemias mainly affect?
WBC
why might Vit B12indicate pancytopenia?
B12 deficiency leads to defective DNA synthesis in hemopoietic precursor - hence resulting in macrocytic and megaloblastic anaemia
what is megaloblastic anaemia?
unusually large and structurally abnormal immature RBC released
what shape does aplastic anaemias have?
normocytic
what is aplastic anaemia?
body stopes producing new RBC - alot less cellular contents
what are symptoms of aplastic anaemia?
SoB, tachycardia, recurrent infections, unexplained bruising, epistaxis, rash, headaches, fever
what does icteric mean?
yellowish pigment - jaundice
why does jaundice occur?
build up of bilirubin - biproduct of RBC breakdown
what is the most common childhood cancer?
acute lymphoblastic leukaemia
what is most common inherited haemolytic anaemia?
hereditary spherocytosis
what do spherocytes look like on blood film?
spherical RBC
no central pallor - due to loss of biconcavity
what is AIHA?
auto-immune haemolytic anaemia
shorted RBC survival can be warm/ cold reactive
on a blood film how does Vit b12 deficiency/ folate show?
macrocytic
what occurs during hereditary spherocytosis?
RBC breakdown as enter spleen
what are signs of hereditary spherocytosis?
jaundice, gall stones, splenomegaly, aplastic crisis in parovirus presence
on a blood film what would hereditary spherocytosis show?
MCHC raised, high reticulocytes, spherocytes
what diagnostic test can be used for AIHA?
coombs test
what is warm AIHA associated with?
similar symptoms to HF/ angina
is cold AIHA more likely to be chronic?
yes
what is cold AIHA linked to?
malaria, EBV
