[sharly62]

Interpreting flow cytometry & FISH test results

by sharly62 on Tue Feb 10, 2015 9:51 am

Could anyone please help decipher these results for us:

Flow cytometric analysis performed on a concurrent bone marrow aspirate sample demonstrates an aberrant plasma cell population that is CD19(-), CD20(dim/subset), CD28(+), CD38(+), CD138(+), CD45(dim), CD56(+), CD81(+), CD117(-), cyKappa(-), and cyLambda(+) .. Cytogenetics: normal male karyotype diploid XY . FISH: Positive result for the presence of a clone with an IGH/CCND1/MYEOV gene rearrangement (translocation) at a low level.

[JimNY]

Re: Interpreting flow cytometry & FISH test results

by JimNY on Tue Feb 10, 2015 11:11 am

I'm not an expert on these things, but I believe the key results from the report are the FISH results at the end. They indicate that the chromosomal abnormality t(11;14) is present in some of the myeloma cells. That's generally not considered to be a bad chromosomal abnormality, and there are some studies that suggest it may even have a positive effect on prognosis.

The first part of the report, before the FISH results, is not so important. It basically says that there were cells found that have markers that are typical for multiple myeloma. Multibilly has posted a nice explanation of these sorts of results a few times here in the forum; see, for example, this posting, where he wrote:

The "CD" designations (like CD38+) that you find on the BMB test results are not to be confused with chromosomal abnormalities. These CD designations are simply what are known as "clusters of differentiation" (or, alternatively, the cell's "immuno­phenotype"), which is just a fancy way of saying that the cell's surface has some specific markers. There are over 300 dif­fer­ent clusters of differ­en­tia­tion. As an example, CD38+ is a common marker that is found pre­dominantly on multiple myeloma cells (which is why certain drugs like some monoclonal antibodies are tuned to look for that specific CD38+ marker).

Healthy plasma cells typically have the following profiles of clusters of differ­en­tia­tion: CD19+, CD45+, CD20–, and CD56–.

Myeloma cells can have the following profiles of clusters of differentiation: CD56+, CD38+, CD138+, CD19-, CD45-, etc.

Some of the CD markers do have diagnostic relevance, and there are some articles discussing their potential prognostic impact. But, I don't recall doctors ever classi­fy­ing the risk of a multiple myeloma patient based on the CD markers alone. Most of the current discussions around risk classification are more centered on one's cyto­genetics (chromo­somal ab­nor­mali­ties).