10. Myelomas and paraproteins Flashcards
When requesting a lab test for possibly myeloma, which of the following is the single most useful test?
Serum electrophoresis
Tells you what exactly the problem is
What conditions are associated with paraproteins
Amyloidosis
Waldenstrom’s macroglobunemia
MGUS
What is an antibody?
An immunoglobulin is just an antibody
Produced by B cells, mostly plasma cells. Can either be soluble of protein bound but there main 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
Describe the structure of an immunoglobulin?
Basic Y shape structure
2 heady chains
2 light chains
FC portion at bottom is recognised by immune system
Fabregion is antigen binding zone and has infinite variability
What are the different types of immunoglobulins?
IgG- most prevalent
IgA- mucous membrane immunity
IgM- Initial phase of antibody production
IgD-
IgE-parasite immune responses, hypersensitivity
How are light chains arranged?
Evenly split between kappa or lambda
What is meant by an immunoglobulin profile?
Tells yiu about the different arrangement of subclasses by measuring heavy chains/Fc
Doesn’t tell you if there’s paraproteins
Doesn’t tell yiu if there all the same
What is a paraprotein
A group of antibodies that are producing monoclonal antibodies. Can be found in the blood of protein
What is serum electropheresis
Seperates proteins based on size and charge
Forms a characteristic patterns of bands of different widths and intensities based on proteins present
What is immunofixation?
Identifies which class of paraproteins are present (IgG, IgM)
What are light chains?
Asesses imbalance/ excess of light chains in urine/serum
Determine the split between kappa and lambda
What does the paraprotein tell you about disease?
IgM- lymphoma, maturing B lymphocytes make IgM antibodies at the start of the immune response
IgA/IgG- myeloma, nature plasma cells generate these types of immunoglobulin after isotoype switching
What is myeloma?
Neoplasticism disorder of plasma cells resulting in excessive production of a single type of immunoglobulin (paraprotein)
Peaks in the 7th decade, clinical symptoms. Result from direct effect of plasma cells or from paraprotein
What are the general features of myeloma?
C- hypercalcaemia
R- renal failure
A- anaemia
B- bone disease
Bone disease- multiple lyric legions, vertebral collapse, pathological fracture
Bone marrow failure esp. anaemia, infections
What do paraproteins cause in the body?
Renal failure- cast nephropathy
Hyper viscosity- syndrome caused by increased viscosity in blood, impaired micro circulation and hypo percussions
Hypogammaglobinaemia
Impaired production of normal immunoglobulin
Tendency to infection