Myeloma Flashcards
What is an antibody?
Produced by B cells, mostly plasma cells
Can be either soluble or membrane-bound
Primary role is to recognise and bind pathogens
This may directly impede the biological process or direct other components of the immune system by “tagging” the antigen
What are the names of heavy chains?
IgM - initial phase of Ab production
IgG - most common
IgA - mucous membrane immunity
IgE - parasite response or hypersensitivity
What are the light chains?
Kappa or lambda
Random selection for each cell
But, each cell will only make 1 type of light chain with 1 specificity
Free light chains are also found in the blood at low levels – difficult to measure
What is paraprotein?
Monoclonal immunoglobulin present in the blood or urine
What is indicated if paraprotein is in the bloodstream or urine?
monoclonal proliferation of B cells or plasma somewhere in the body
What tests can be used to assess antibodies and paraproteins?
Total immunoglobulin levels
- Measures Ig subclasses by heavy chain/ Fc section
Electrophoresis
- Assesses antibody diversity, identifies paraprotein
Immunofixation - Identifies what class of paraprotein is present (i.e. IgG, IgM)
Light chains
Assesses imbalance/ excess of light chains in urine / serum
What do IgM paraproteins indicate?
Lymphoma
What do IgG or IgA paraproteins indicate?
Myeloma
What is myeloma ?
Neoplastic disorder of plasma cells, resulting (usually) in excessive production of a single type of immunoglobulin (paraprotein)
What are the features of myeloma?
bone disease lytic bone lesions pathological fractures cord compression hypercalcaemia bone marrow failure esp. anaemia Infections
CRAB – hyperCalcaemia, Renal failure, Anaemia, Bone disease
What are the effects of the paraprotein in myeloma?
Renal failure - cast nephropathy
Hyperviscosity - bleeding in retinal, oral, nasal or cutaneous ares
Hypogammaglobulinaemia - impaired production of normal immunoglobulin = infection
Amyloidosis - deposition of fibrillar protein in orans
How is myeloma diagnosed?
Biopsy where plasma cells in bone marrow
What is myeloma treatment?
Chemotherapy Proteasome inhibitors (carfilzomib, bortezomib), IMiDs (lenalidomide, pomalidomide), monoclonal antibodies Bisphosphonate therapy Zoledronic acid Radiotherapy Steroids Surgery Pinning of long bones; decompression of spinal cord Autologous stem cell transplant
