Dysproteinurias Flashcards
single myeloma
plasmacytoma
where do myelomas arise from
bone marrow
what happens in myeloma
- malignant clonal proliferation of abnormal plasma cells which accumulate in the bone marrow
- produce abnormal proteins (defective IgG) that are deposited throughout many organ sites
- this is known as AL amyloidosis
how is the IgG seen as on electrophoresis
paraprotein or monoclonal band
3 domains of symptoms in myeloma
- renal impairement
- haematological
- bones
what happens to the kidneys
AL amyloidosis and monoclonal Ig deposition in glomerulus
- amyloidosis results in increased permeability with proteinuria, often progressing to nephrotic syndrome
- precipitation of abnormal light chains (Bence Jones protein) in renal tubules is toxic to epithelial cells - leads to acute renal failure
what happens to the immune system
- anaemia, neutropenia, thrombocytopenia (low platelets)
- this may result from bone marrow infiltration by plasma cells
- leads to symptoms of anaemia, recurrent infection and bleeding
what happens to the bones
bone destruction is common
- myeloma cells activate osteoclasts (and not osteoblasts) - increased bone breakdown
- ache (eg backache), pathological fractures, verterbal collapse
- hypercalcaemia - may be symptomatic
how may hypercalcaemia present (renal system)
renal stones
what is needed to make a diagnosis
a high index of suspicion eg bone ache that is not improving (could be back ache)
what is seen under polarized light
apple green birefringence when staining with Congo Red and seen under polarized light
blood investigations
serum protein electrophoresis
serum free light chains
urine investigation
Bence Jones protein assay
what is seen on bone marrow biopsy
investigations:
- bloods
- urine (BJ)
- bone marrow biopsy
- skeletal survey of X rays
- renal biopsy
