CP39 - HAEMOGLOBINOPATHIES and OBSTETRIC HAEMATOLOGY Flashcards
what controls the production of RBC?
by erythropoietin which is produced in the kidneys in response to tissue oxygen concentration
what are some physiological changes in pregnancy
plasma volume expands in pregnancy by 50%
red cell mass expands by 25%
MCV increases physiologically in pregnancy due to mobiliation of iron
when does physiological anaemia happen
pregnancy
what happen to the WBC during pregnancy
WBC is present in the placenta as pregnancy forces them out of bone marrow
what happen to the platelet account during pregnancy
Platelet count falls after 20weeks and thrombocytopenia is most marked in late pregnancy
what state does pregnancy put thrombosis?
pregnancy is a pro-thrombotic state
what sort of condition is sickle cell anaemia?
haemolytic anaemia
what are the underlying causes to the admintion of the sickle cells anaemia to hospital?
sickle cells depositino on vessels and block blood flow and cause ischemia
then the ischaemia of the tissue cause painful episodes - hospital
which type of haemoglobulin is the normal type
Hb - A
what is sickle cells trait
it is the presence of only one copy of the sickle cell gene ie heterozygous
Hb-A/S - Hb-S 45%, Hb-A 55%
when does sickle cells trait become a clinical problem
when severe hypoxia
what is the genetic make up of sickle cell disease
Hb S/S
what is the clinical feature for sickle cell disease
decreased RBC count , RBC sickle cell shape
Hb S > 95
what are some acute complications for sickle cell disease?
vasco-occlusive crisis - hans and feet (dactylitis), chest syndrome, abdo pain
what is the medical emergency for sickle cell disease
sequestration crisis - blockage of major blodd vessels (spleen, liver)
what are some chronic complications for sickle cell disease?
Hyposplenism - due to infarction and atrophy of spleen.
Renal disease: medullary infarction with papillary necrosis.
Tubular damage - can’t concentrate urine (bed-wetting at night). Glomerular – chronic renal failure/dialysis
Avascular necrosis (AVN) –femoral/humeral heads
Leg ulcers, osteomyelitis, gall stones, retinopathy, cardiac, respiratory
what are some treatment for sickle cell diseases
penicillin from 6 months
acute crisis
vaso-occlusive - analgesia
priapism (persistent and painful erection of the penis)
transfusion - splenic sequestration, aplastic crisis, pre-operative, acute chest crisis
Exchange: Acute chest crisis, acute stroke, pre-operative.
Regular exchange: Primary and secondary stroke prevention
Hydroxycarbamide - increases Hb F (time delay to polymerisation, reduced adhesion to endothelium, enhances NO)
Bone marrow transplant
what is thalassaemia
it is a genetic condition which causes production of Hb with different ratios of alpha and beta chains
what is the composition of alpha thalassaemia
all 4 chains are alpha - generally not survivable
what is the pathogenesis in beta thalassaemia
Reduced rate of production of beta-globin chains (pathology caused by excess alpha chains)
what is the chain composition of thalassaemia major ?
both copy of the genes produce beta chain - ie produce little to none Hb-A - often fatal if untreated
what is the histology of beta-thalassaemia trait?
microcytic hypochrontic Hb which resemble iron deficiency
what is the main histology of β-THALASSAEMIA MAJOR
lots of nucleated red cells
what is the pathology of β-THALASSAEMIA MAJOR?
anaemia (alpha chain excess)
increase bone marrow activity (to increase production of RBC by the body) - skeletal deformity
enlarged and overactive spleen - increase transfusion requirement
