Red cells 2 - acquired anaemias Flashcards
What does normal haemoglobin depend on?
sex, age, ethnicity, time sample taken etc..
Normal male Hb values
12-70 (140-180)
>70 (116-156)
Normal female Hb values
12-70 (120-160)
>70 (108-143)
clinical features of anaemia
SOB pallor tiredness dizziness ankle swelling
Underlying causes clinical features of anaemia
bleeding eg menorrhagia, GI bleed
malabsorption eg diarrhoea
splenomegaly and jaundice
bone marrow pathophysiology anaemia
cellularity, stroma, nutrients
RBC pathophysiology anaemia
membrane, enzymes, haemoglobin
destruction/loss anaemia pathophysiology
bleeding
haemolysis
hypersplenism
MCV
mean cell volume = cell size
MCH
mean cell haemoglobin
3 morphological types of anaemia
hypochromic microcytic
normochromic normocytic
macrocytic
What you would measure in each of the 3 morphological types of anaemia
Hm = Serum ferritin Nn = Reticulocyte count M = Vit B12/folate or bone marrow
serum ferritin results and what they mean
low = iron deficiency anaemia normal/high = secondary anaemia, thalassaemia
Is there a pathway for excess iron excretion?
no
What happens to absorbed iron?
bound to mucosal ferritin and shedded OR
transported across basement membrane by ferroportin
What is iron bound to in plasma?
transferrin
What is iron stored in cells as?
ferritin
hepcidin
produced by hepatocytes
bind to ferroportin and stop iron absorption
chronic anaemia of inflammatory diseased
History - iron deficiency anaemia
dyspepsia/Gi bleed, menorrhagia, diet, increased requirement eg pregnancy, malabsorption eg coeliac
Examination - iron deficiency anaemia
koilonychia
tongue atrophy and angular cheilitis
abdominal and rectal
managing iron deficiency anaemia
oral iron (IV if intolerant)
rarely blood transfusion
diet, ulcer therapy, gynae etc..
Reticulocyte findings and what it means
increased - acute blood loss/haemolysis
decreased - marrow infiltration , secondary anaemia
haemolytic anaemia - 2 main things
increased red cell destruction = decrease Hb
compensation by bone marrow = increase Reticulocyte count
extravascular and intravascular haemolysis
extravascular = reticuloendothelial system and immune mediated intravascular = in vessels, non immune mediated
congenital haemolysis
hereditary spherocytosis
enzyme deficiency
haemoglobinopathy
acquired haemolysis
autoimmune mechanical (heart valve), PET, DIC, infection
Direct antiglobulin test
detects antibody or complement on RBC
reagent is anti human IgG or anti complement
DAGT results and what they mean
\+ve = immune mediated -ve = non-immune mediated
How to find out if patient is haemolysing
FBC reticulocyte count blood film serum bilirubin heptaglobin
How to find out the mechanism of haemolysis
AGT, urine, blood film
managing haemolysis
support marrow function - folic acid
autoimmune - steroids
splenectomy, transfusion?
remove valve, infection, sepsis etc
secondary anaemia type
normochromic normocytic
megaloblastic anaemia
B12/folate deficiency
non-megaloblastic anaemia
marrow infiltrate
drugs
appearance of megaloblastic anaemia
yellow tinge - bilirubin
Vitamin B12 absorption
binds to intrinsic factor made by parietal cells
absorbed in distal ileum
commonest cause of B12 deficiency
pernicious anaemia
pernicious anaemia
auto antibodies directed against INTRINSIC FACTOR
How long does it take for pernicious anaemia symptoms to appear?
1-2 years
megaloblastic anaemia treatment
B12 - im injection
oral folate –> ensure B12 levels normal if neuropathic symptoms
other causes of macrocytosis
drugs eg ART, methotrexate
hypothyroidism
alcohol
disordered liver function
