Haemolysis flashcards
Causes of spherocytosis
Hereditary spherocytosis (30% neg family history, MCHC increased) warm AIHA phosphate deficiency on TPN Severe burns Wilson's disease copper def Clostridium welchii sepsis
Evidence of haemolysis
reticulocytosis Spherocytosis, sickled cells Hyperbilirubinaemia Elevated LDH Low haptoglobin Urinary and faecal urobilinogen raised Raised plasma Hb* Haemoglobinuria* Urinary haemosiderin* Methaemalbuminaemia*
- means intravascular
Symptoms/clinical syndromes with hereditary spherocytosis
Jaundice Splenomegaly Gall stones leg ulcers haemolytic crisis aplastic crisis
Diagnosis hered spherocytosis how?
Blood film
negative DAT
Flow cytometry- reduced binding of eosin 5 malemide
Can do osmotic fragility test but not very specific
What are the two types of autoimmune HA in adults?
Warm -over 85%
cold agglutinin haemolysis - less than 15%
Secondary causes of immune haemolytic anaemia
lymphoproliferative disorders- CLL main association
other malignancy
infection
CTD
Which drugs can induce an AIHA?
Penicillin- haptens
quinine, rifampicin - immune complexes
Cephalothin- non specific adsorption onto red cell
management of warm AIHA?
supportive care, transfusion where severe
steroids similar to ITP dosing (downregulate Fc receptors on macrophages and decrease autoab production)
second line splenectomy and rituximab
if refractory, cyclosporine or cyclophosphamide, MMF (no evidence aza, IVIG, plasma exchange)
What does cold agglutinin haemolysis mean?
Occurs only when complement cascade proceeds to completion, with haemolysis limited by thermal amplitude of the IgM and physiological inhibitors of the complement cascade.
Cold agglutinins associated with
Infections- mycoplasma, EBV
Lymphoma
Note DAT positive to C3d only
Note haemolysis is intravascular
Treat cold agglutinins with
Keep warm
Rituximab
If mixed warm/cold can give pred
sometimes there is no associated haemolysis so do nothing
Causes of microangiopathic HA
DIC TTP HUS prosthetic valve Pre-eclampsia Vascular malformation Brown snake bite Disseminated mucoid adenoca
TTP/HUS associations
Idiopathic Familial Infection e coli o157:H7, HIV SLE pregnancy chemo (cisplatin, mitomycin, gemcitabine) bone marrow tx Drugs (quinine, cyclosporine)
What is the defect in PNH?
Acquired clonal stem cell disorder
Due to deficiency in complement regulatory protein- lack of GP1 anchored proteins results in increased sensitivity of red cells to complement (Hams test positive), lack of CD59 on red cells and CD 16 on neutrophils via flow cytometry
What is the treatment for PNH?
Eculizumab- reduces haemolysis and transfusion
Ab against terminal complement protein C5
