haemolysis Flashcards
what is haemolysis?
breakdown of RBC
how does haemolysis present?
normocytic or false macrocytic anaemia - pale, fatigue
jaundice
dark urine
splenomegaly
hepatomegaly
what are the clinical results for intravascular haemolysis?
low haptoglobin
increased LDH
increased urine Hb and hemosiderin
schistocytes
what are the causes of intravascular haemolysis?
G6PD deficiency
ABO mismatch
malaria
drug-induced
what are the clinical results for extravascular haemolysis?
increased unconjugated bilirubin
increased LDH
splenomegaly
target cells
what are the causes of extravascular haemolysis?
thalassaemia
sickle cell
hereditary spherocytosis
autoimmune haemolytic anaemia
what immunoglobulins are involved in autoimmune acquired haemolysis?
warm IgG
cold IgM
what are the causes of warm IgG autoimmune acquired haemolysis?
autoimmune (SLE)
drugs
infections
what are the causes of cold IgM autoimmune acquired haemolysis?
infections
lymphoproliferative disorders
what causes alloimmune acquired haemolysis?
haemolytic transfusion reaction
what causes mechanical autoimmune acquired haemolysis?
DIC
TTP
haemolytic uraemic syndrome (HUS)
infections
burns
prosthetic heart valve
what are acquired causes of abnormal cell membrane?
liver disease
vitamin E deficiency
what are congenital causes of abnormal cell membrane?
hereditary spherocytosis
altered spleen (inc transit time)
what are congenital causes of abnormal red cell metabolism?
G6PD deficiency
failure to generate ATP
what are genetic causes of abnormal haemoglobin?
sickle cell disease
how do we confirm haemolysis?
FBC - inc. reticulocytes, inc. serum unconjugated bilirubin, inc. urinary urobilinogen
inc. LDH - indicated increased cellular breakdown
what does direct coomb’s test identify?
warm and cold autoimmune haemolytic anaemia
what does indirect coomb’s test identify?
screening in antenatal care and RBC phenotypical for transfusions
what type of transmission is G6PD deficiency?
x-linked
what type of transmission is hereditary spherocytosis?
autosomal dominant
how does G6PD deficiency cause haemolysis?
reduced NAPDH leads to oxidative stress, too much gutathione
how will a patient with G6PD deficiency haemolysis present?
rapid onset jaundice and anaemia
how does hereditary spherocytosis cause haemoylsis?
abnormal RBC shape
inc. sequestration in spleen
extravascular haemolysis
how would a patient with hereditary spherocytosis haemolysis present?
young child
Fhx splenectomy
jaundice, mild anaemia, splenomegaly
what would blood film show in G6PD deficiency haemolysis?
Heinz bodies
Bite cells
