AIHA

Question 1

What

Answer 1

Mediated by autoantibodies causing mainly extravascular haemolysis and spherocytosis.
Most commonly idiopathic, may be secondary to lymphoproliferative disorder, infection or drugs
Positive DAT

Question 2

Types

Answer 2

Warm and cold

Classified according to optimatl binding temp to RBCs

Question 3

Warm AIHA

Answer 3

IgG mediated
Bind at body temperature
Rx: steroids, immunosuppression (+/- splenectomy)

Question 4

Cold AIHA

Answer 4

IgM mediated
Bind at low temps (4 deg)
Activate cell surface complement
Chronic anaemia, made worse by cold
Often Raynaud's or acrocyanosis
Rx: Keep warm, chlorambucil

Question 5

Causes

Answer 5

Mostly idiopathic
Warm: lymphoproliferative (CLL, lymphoma), drugs, autoimmune disease eg DLE
Cold: may follow infection (mycoplasma, EBV)