2: Microangiopathic Haemolytic Anaemias Flashcards
What is a microangiopathic haemolytic anaemia
RBC damage in circulation causing intravascular haemolysis
What are the 3 types of MAHA
- DIC
- TTP
- HUS
Which age group does TTP occur in
Middle-age (40 years)
what. gender is TTP more common in
women
what ethnicity is TTP more common in
afro-carribean
what causes TTP
autoantibodies to ADAMST13 a protein that cleaves and inactive VWF
what is the mnemonic to remember symptoms in TTP
Nasty Fever Ruined My Tubes
what neurological symptoms are associated with TTP
- Headache
- Altered mental status
- Seizures
what is the F in TTP
Fever
what are symptoms of renal function impairment in TTP
- Proteinuria
- Haematuria
what are symptoms of MAHA
- Pallour
- Dyspneoa
- Jaundice
what are symptoms of thrombocytopenia
- Bleeding gums
- Petechiae
- Purpura
explain pathophysiology of MAHA
- Autoantibodies to ADAMST13 means no longer can cleave VWF causing permanent activation
- Activation results in micro thrombi formation which occlude arterioles and capillaries resulting in fragmentation of RBC
- Microthrombi occluding arterioles and capillaries result in ischaemia of end organs (kidneys and brain)
how will FBC present in TTP
- Anaemia
- Thrombocytopenia
how will coagulation studies present in TTP
- Increase APTT and PT
how will d-dimer present in TTP and why
- Increase - due to clot degredation
explain coombs test in MAHA
Coombs test will be negative
what will be seen on peripheral blood smear in TTP
Schistocytes
what may be seen on U+E and why
Increase urea and creatinine due to renal failure
what is used to managed TTP
Plasma exchange therapy
Glucocorticoids
in which age group does haemolytic uraemia syndrome occur
Under 5-years
what infection causes haemolytic uraemia syndrome
E.COLI O157:H7
explain manifestation of haemolytic uraemia syndrome
Diarrhoea illness then 5-10d later manifests with MAHA, thrombocytopenia and renal failure
how does thrombocytopenia present clinically
Bleeding
Petechiae
Purpura
