Bcl-2/ t(14;18) Gene
Rearrangement, Quantitative Real-Time PCR - Questdiagnostics
BCL-2 is a pro-survival protein that is produced by many lymphoma
cells as a result of a
translocation
of a gene - (t(14:18). PCR testing
can be used to detect very small amounts of this gene in the
blood
or bone marrow.
When the PCR test is negative (a good result),
it means that there may be no abnormal cells in
the blood or marrow, which might be described as a molecular remission
...
The clinical significance of a molecular remission is still not clear, but achieving this kind or response
has been associated
with longer duration of response among the participants in some
studies.
PCR tests are generally given after a complete
response to treatment
has been determined using CT and bone marrow, mainly in clinical trials.
"The t(14;18) translocation is characteristic of B-cell
lymphomas, occurring in up to 90% of follicular
lymphomas. It is also found in 20% to 30% of diffuse large
B-cell lymphomas ..."
analytical sensitivity of 1 tumor cell in 100,000
normal cells.
What is PCR Testing? -
opa.faseb.org
PDF
"Sometimes referred to as "molecular
photocopying," PCR can characterize, analyze,
and synthesize any specific piece of DNA or RNA. ... Medical
research and clinical medicine
are profiting from PCR mainly in two areas: detection of
infectious disease organisms, and detection
of variations and mutations in genes, especially human
genes."
A limitation of the test is that
it can only show the status of the compartment tested: the blood or marrow.
A conversion to negative appears to be a good prognostic indicator, but not
definitively, because the test can't determine the t:14:18 status in
lymph nodes and other areas.
When bcl-2 / t:14:18 shows positive in the blood after chemo and then converts to negative after vaccine
suggests to me that the vaccine is active ... but not necessarily resulting in clinical benefit,
because it's probably easier for the immune system to " delete" tumors that are circulating in the
blood.
But I think it reinforces the concept that using vaccine in patients with minimal residual
disease is a
plausible idea. ~ KarlS
