Advanced Flashcards
1
Q
Polymerization
A
IgA, IgM, and free light chains can polymerize if in excess. Will appear as multiple restrictions of same type on immnotyping
must depolymerize and test again : most used reducing substances:
- Beta-mercaptoethanol (BME or 2 ME)
- Dithiothreitol (DTT)
- theses cleave and reduce disulfide bridges
- if one peak after reducing, you can conclude it was one monoclonal gammopathy
2
Q
Heavy Chain Disease
A
rare B-cell neoplasms that are clinically and morphologically distinct from one another but that have in common the production of an abnormal immunoglobulin heavy chain incapable of binding light chains.
- the altered heavy chains contain deletions, insertions, and point mutations that result in loss of a large portion of the constant-1 domain responsible for light chain binding
- this common feature gives rise to three different diseases dependent on the heavy chain class that is produced, each with a unique clinical presentation
- isolated B-1 fraction increase
- only subtracted in one heavy chain area, and no subtraction of kappa or lambda
- confirm with different method (IFE)
3
Q
Interferences in Beta-2 fraction
A
- peak in Beta-2 that is not subtracted by any antisera
- verify the sample is a plasma sample (not serum as it should be )
- very if the patient received an injection of iodinated contrast product recently
- contrast dyes absorrb at 200 nm wavelength and are visible on capillary technologies (SPE and IT)
- can appear on SPE if given in last 2 to 6 days
Alpha2 fraction : omnipaque, ultravist, visipaque, iopamiron, telebrix, hexabrix, xenetix
Beta2 fraction - lomenron, optiject
- contrast dye is eliminated after 24-48 hours
4
Q
IgG4 - related disease
A
- uncommon systemic immune-mediated disease with a heterogeneous clinical presentation affecting a wide range of organ systems
- characterized by the infiltration of IgG4-breaing plasma cells and raised IgG4 levels
- mean age of diagnosis is 60 years with clear male predominance
- polyclonal IgG4 Ab migrate to a well-defined, focal, yet relatively broad electrophoretic area (beta-gamma bridging) and left skewed gamma curve
5
Q
dilute sample
A
if peaks don’t completely disapear after using hyper gamma antisera
6
Q
A
