basics Flashcards
describe neutrophils
polymorphs (take various forms)
phagocyte invaders
attract other cells to site of injury/infection
increased in stress
describe eosinophils
bi-lobed, red granules
hypersensitivity reactions
fight parasites
allergic conditions
describe basophils
large deep purple
tissue mast cells
mediate hypersensitivity reactions
granules contain histamine
describe monocytes
phagocytose invaders
liver longer than neutrophils
describe lymphocytes
small with condensed nucleus and rim of cytoplasm
released in response to infection
where is erythropoietin made?
kidneys
what is erythropoietin released in response to and what does it stimulate?
hypoxia and RBC production
where does red cell destruction occur?
liver and spleen
red cells taken up by macrophages
what do the products of red cell destruction make?
globin chains = amino acids
haem = iron and bilirubin
what will happen if a cell has no mitochondria?
no kreb’s cycle, relies on glucose metabolism
what will happen if a cell has no nucleus?
can’t divide, can’t replace damaged proteins, limited lifespan
what will happen if a cell is stuffed with Hb?
high osmotic pressure, needs to pump ions to stop swelling
what is iron in its reduced form
Fe2+ -> Fe3+ = stopped by NADH (electron donor)
what is needed for cells susceptible for oxidative stress?
glutathione, stops H2O2 forming, G6PG = rate limiting enzyme
how is microcytic anaemia seen on blood results?
low Hb and low MCV
what is microcytic anaemia due to?
haemoglobinisation problems
what are the causes of microcytic anaemia?
TAILS
thalassaemia
anaemia of chronic disease
iron deficiency
lead poisoning
sideroblastic anaemia
what is the most common cause of microcytic anaemia?
iron deficiency
what is functional iron?
haemoglobin
what is transported iron?
serum iron, transferrin
what is iron stored as?
serum ferritin
what inhibits iron transport?
hepcidin
what is thalassaemia caused by?
fucked up globin chain
what is iron deficiency anaemia, anaemia of chronic disease caused by?
fucked up iron part of the haemoglobin chain
what is sideroblastic anaemia caused by?
fucked up part of protoporphyrin part of haemoglobin chain
what are the 2 haemoglobinopathies?
thalassaemia and sickle cell
what are the different types of haemoglobin?
haemoglobin A - HbA, HbA2, HbF
2 alpha chains
2 beta chains
when does sickle cell occur?
when there’s a mutation that alters haemoglobin structure
what is the diagnostic sign of beta-thalassamia?
raised HbA2
what are the clinical signs and symptoms of alpha thalassaemia?
trait - asymptomatic, possible low MCV
full disease -moderate anaemia, very low MCV
patient presents with jaundice, splenomegaly
fetalis - not compatible with life
what are the clinical signs and symptoms of beta thalassaemia?
babies - HbF falls - pale, failure to thrive
what is the treatment for beta thalassaemia?
regular transfusions for live (side effect = iron overload)
meds = desferrioxamine
what is the pathophysiology of a sickle crisis?
in low O2 levels, HbS polymerises and distorts shape of red cell leading to vaso-occlusion = sickle crisis
what investigations are used for sickle crisis?
FBC (Hb, RBC)
blood film (target cells, teardrop cells)
haemoglobin electrophoresis = beta thalassaemia (identifies HbS and if HbA2 raised)
how do you treat a sickle crisis?
acute - analgesia, hydration, oxygen
chronic - if hyposplenism = prophylactic penicillin, folic acid, hydroxycarbamide (hydroxyurea)
what are the underlying causes of AOCD?
causes of inflammation, autoimmune, malignancy, disease
how does AOCD present?
microcytic/normocytic anaemia
chronic infection
autoimmune conditions
HIGH SERUM FERRITIN
how do you treat AOCD?
treat underlying cause
recombinant EPO and iron supplements
what are the blood findings of iron deficiency anaemia?
decreased functional iron (Hb) + reduced storage iron (low serum ferritin)
what are the causes of IDA?
diet - vegetarian
pregnancy
blood loss - menorrhagia, GI bleeds (ulcers, tumours) NSAIDs, haematuria
coeliac
what does negative iron balance lead to?
iron deficient erythropoiesis - falling RBC MCV
microcytic anaemia
epithelial changes - skin, koilonychiaw
what is management for IDA?
iron supplementation
how does lead poisoning present?
cognitive defects
peripheral neuropathy
renal dysfunction
neuro signs + microcytic anaemia = LEAD POISONING
what is sideroblastic anaemia?
impaired haem synthesis as can’t put iron and protoporphyrin together = IRON OVERLOAD
how does acquired sideroblastic anaemia present and what are the causes?
macrocytic anaemia
myelodysplastic syndromes, drugs and toxins
how does congenital sideroblastic anaemia present and how is it passed on?
microcytic, hypochromic anaemia
x-linked
how does sideroblastic anaemia generally present?
weakness, fatigue, difficulty breathing
iron overload -> hepatomegaly/splenomegaly, arrhythmias
what investigations are used in sideroblastic anaemia and what will be seen on it?
blood film
increased reticulocytes, stippled RBCs (basophilic stippling)
what is the management for sideroblastic anaemia?
pyridoxine
iron overload = deferoxamine
what is the initial investigation for macrocytic anaemia
blood smear
