Myeloma Flashcards
Definition of myeloma
Malignant clonal proliferation of plasma cells
What does a monoclonal band on serum/urine electrophoresis represent? How does this differ from normal?
identical immunoglobulins produced by a single clone of plasma cells. Usually one plasma cell produces different immunoglobulins
Commonest type of myeloma
IgG
Why are patients with myeloma prone to infection?
Immunoparesis- low levels of other Ig
What are Bence Jones proteins?
Free Ig light chains (kappa or lambda) appearing in the urine
Symptoms of myeloma (5)
Ostelytic bone lesions causing pain, fracture Hypercalcaemia symptoms Bone marrow suppression symptoms Recurrent bacterial infections Renal impairment
Tests in myeloma:
a) FBC
b) blood film
c) skeletal survey
d) serum and urine electrophoresis
e) bone marrow biopsy
f) urine microscopy
a) anaemia, may be neutropenia/thrombocytopenia if marrow infiltration
b) rouleaux formation
c) osteolytic lesions
d) monoclonal banding
e) increased plasma cells
f) casts
Treatment of myeloma (4)
Corticosteroids
Alkylating agents e.g. cyclophospamide
Thalidomide
High dose chemo and autologous stem cell transplant in fit patients
Management of bone disease (4)
Opiate analgesia (avoid NSAIDs)
Bisphosphonates
Vertebroplasty
Local radiotherapy
How does myeloma cause lytic bone disease?
Release of IL-6 causing suppression of osteoblasts and activation of osteoclasts
Definition of MGUS (3)
Paraprotein in serum
What is the risk of MGUS?
Progression to myeloma
What is amyloid?
Extracellular deposits of abnormal protein that are resistant to degradation
What cause AL amyloidosis?
Insoluble sheets of light chain from a small mutated plasma cell clone
How does AL amyloidosis present?
Slowly progressive multisystem disease
Organ damage in AL amyloid
a) kidney
b) heart
c) liver
d) nervous
e) GI
a) nephrotic syndrome
b) restrictive cardiomyopathy
c) hepatomegaly and deranged LFTs
d) peripheral and autonomic neuropathy, carpal tunnel syndrome
e) malabsorption
Tests in AL amyloid
isotope scan showing high uptake in affected organs
Fat/organ/rectal biopsy with Congo Red stain- “apple green birefringence” under polarised light
Lymphoplasmacytoid neoplasm causing a characteristic IgM paraprotein
Waldenstrom’s macroglobulinaemia
Tumour effects in WM (3)
lymphadenopathy
splenomegaly
marrow failure
Effects of the paraprotein in WM (2)
Hyperviscosity
Neuropathy
Cliical features of hyperviscosity (4)
Lethargy
Confusion
Visual disturbance
Cardiac failure
Treatment of hyperviscosity
Plasmapharesis
Describe the structure of antibody
Made of two heavy chains and two light chains; has a variable region determining antigen specificity
How is the variable element generated?
From V-D-J light-chain recombination in the precursor B-cell
What do immature B cells express on their surface and where do they go after leaving the bone marrow?
Express IgM and IgD, go the lymph nodes
Responses of the B cell to activation
Somatic hypermutation and class switching
