Myeloma Flashcards
associated with paraprotein
waldenstrom’s macroglobulinemia
MGUS
incidence is higher than myeloma
antibodies
can be either soluble or membrane bound
primary role is to recognise and bind pathogens
heavy chains (Fc portion)
Gamma – IgG Alpha – IgA Mu – IgM Delta – IgD Epsilon - IgE
paraprotein
monoclonal immunoglobulin present in blood or urine
If present, it tells us that there is monoclonal proliferation of a B lymphocyte / plasma cell somewhere in the body
serum protein electropherersis
separate protein based on size and charge
bands of different widths and intensities
summary of tests
Total immunoglobulin levels
Measures Ig subclasses by heavy chain/ Fc section
Electrophoresis (what identifies paraprotein)
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
immunoglobulin subclass by disease
IgM paraproteins = lymphoma
Maturing B-lymphocytes make IgM antibody at the start of the immune response
IgG, IgA paraproteins = myeloma
Mature plasma cells generate these types of immunoglobulin after isotype switching
IgM
most commonly present as the antigen receptor on the B-cell surface.
myeloma
Neoplastic disorder of plasma cells, resulting (usually) in excessive production of a single type of immunoglobulin (paraprotein)
Peaks in 7th decade
Clinical manifestations may result from direct effect of plasma cells, or effect of paraprotein
Features
CRAB – hypercalcaemia, renal failure, anaemia, bone disease
effects with paraprotein
renal failure-cast nephropathy
-hyperviscosity
by increased viscosity in blood, impaired microcirculation and hypoperfusion
Commonest
bleeding – retinal, oral, nasal, cutaneous
Can also cause cardiac failure, pulmonary congestion, confusion, renal failure
-Hypogammaglobulinaemia
Impaired production of normal Immunoglobulin
Tendency to infection
-Amyloidosis
-deposition of fibrillar protein
Morphological appearances, physical structure are similar
Biochemical or protein composition can vary
When caused by a paraprotein or light chains – AL amyloid
Nephrotic syndrome Cardiac failure (LVH) Carpal tunnel syndrome Autonomic neuropathy Cutaneous infiltration
diagnosis
Myeloma is diagnosed by finding excess plasma cells in the bone marrow
Must comprise > 10% of total bone marrow cell population
monoclonal gammopathy of uncertain significance (MGUS)
Paraproteins are common
3-4% of population over age of 75
The vast majority have nothing wrong with them
types of paraprotein
IgG 55% IgA 21% Light chain only 22% Other (IgD, non-secretory) 2% stage based on albumin & beta 2 microglobulin (not important)
