haematology - acquired haemolytic anaemias Flashcards
classification of acquired haemolytic anaemias
autoimmune (Coomb’s +ive)
- warm
- cold
- paroxysmal cold haemoglobinuria
non-immune (Coomb’s -ive)
- paroxysmal nocturnal haemoglobinuria
- microangiopathic haemolytic anaemia
- thrombotic thrombocytopenia purpura
- haemolytic uraemia syndrome
Coomb’s test
+ive = +ive direct antiglobulin test (DAT)
features of warm AIHA
IgG
37°C
+ Coomb’s
spherocytes
features of cold AIHA/agglutinin disease
IgM
<37°C
+ Coomb’s
Raynauds
causes of WAIHA
mainly primary idiopathic lymphoma CLL SLE methyldopa
causes of cold AIHA/agglutinin disease
primary idiopathic
lymphoma
infections (EBV, mycoplasma)
management of WAIHA
steroids
splenectomy
immunosuppression
management of cold AIHA/agglutinin disease
treat underlying condition
avoid cold
chemotherapy if lymphoma
paroxysmal cold haemoglobinuria is usually caused by
viral infection, eg. measles, syphilis, VSV
what antibodies are found in PCH
Donath-Landsteiner antibodies
what do Donath Landsteiner antibodies do
present in PCH
stick to RBCs in cold
complement mediated haemolysis on rewarming
PCH is self limiting because
self limiting as IgG mediated they dissociate at higher temp than IgM
paroxysmal nocturnal haemoglobinuria
acquired loss of protective surface GPI markers on RBCs, platelets, and neutrophils
- causes complement mediated lysis
features of paroxysmal nocturnal haemoglobinuria
morning haemoglobinuria
thrombosis
Budd-Chiari syndrome - hepatic venous thrombosis
dx of paroxysmal nocturnal haemoglobinuria
immunophenotype shows altered GPI
Ham’s test (in vitro acid-induced lysis)
