Part two - spleen

Question 1

Causes of splenomegaly

Answer 1

C - cysts
H - haematological
* Myeloproliferative disease
* Spherocytosis
* Thalassaemia
I - immunological/infiltrative and infection
* RA, SLE
* Sarcoidosis
* EBV, CMV, malaria, infective endocarditis
M - malignancy/metastases
* Haematological malignancies - lymphoma, leukaemia, haemangiosarcoma
* Metastases - lung, oancreas, stomach
P - portal hypertension

Question 2

Define OPSI

Answer 2

A fulminant and rapidly fatal illness that complicates bacteraemic infections due to encapsulated pathogens which are normally cleared from the circulation by the spleen.

Question 3

Risk factors for OPSI

Answer 3

Haematlogic indication for splenectomy
Uneducated
Unimmunised
No prophylactic antibiotics
Within two years of splenectomy
Children
-- reduced IgM production
-- reduced clearance of bacteria from blood
-- reduced opsonic activity

Question 4

Pathogenesis of OPSI

Answer 4

Encapsulated gram positive organisms usually cleared by the spleen

Impaired phagocytosis due to absence of splenic pulp
Decreased IgM production and opsonisation due to no white pulp