[jane84]

Translation of flow cytometry results

by jane84 on Wed Apr 08, 2015 10:50 am

Hello,

Could somebody please help me with the results I got yesterday :

CD56 6.3 %
CD138 2.3 %
CD138+CD45+ 0.3 %
CD138+CD45- 2.1 %
CD138+CD56+ 1.5 %
CD138+CD56- 1.0 %
CD38 strong intensity 2.5 %
CD45 92 %

I had deletion 13q14, monosomy 14q32, and trisomy 9 (in FISH) when I was diagnosed in 2012. I had induction with Velcade, thalidomide and dexamethasone, followed by an autologous stem cell transplant (ASCT) with melphalan and consolidation with Velcade and dexamethasone (no maintenance).

I am now starting a new therapy with Revlimid 25 mg and dex 20 mg.

Thank you for your help
Jane

[blair77]

Re: Translation of flow cytometry results

by blair77 on Thu Apr 09, 2015 12:43 am

You would need FISH results to check for genetic abnormalities. The flow doesn't really give you much except perhaps your total plasma cell count. The type of expression could help with drug choice also I believe. Do you have your new FISH results?

[jane84]

Re: Translation of flow cytometry results

by jane84 on Thu Apr 09, 2015 5:27 am

Hello Blair77,

The only new FISH results my haematologist told me about is gain 1q21. I don't know about the other results, but I remember reading some time ago that 1q21 together with deletion 13q14 was of bad prognosis. What does that mean exactly?

Thank you again.

[mikeb]

Re: Translation of flow cytometry results

by mikeb on Thu Apr 09, 2015 1:38 pm

Hi Jane,

I am going to go out on a limb here, not sure that my interpretation is correct, but hoping it might be some help to you. I'm hoping someone more knowledgeable here can verify my interpretation or shoot it down.

I think the point of the flow cytometry test in your case is to try to determine the nature of the myeloma cells that you now have and see how likely they are to respond to the Revlimid + dex therapy that you're starting.

The CD56 etc. refer to protein "receptors" commonly found on myeloma cells. I think that the percentages refer to the % of plasma cells in your bone marrow aspirate that had each of the different types of receptors (or combinations of receptors).

I did some quick searching just now, but I could not find anything saying which of the receptors Revlimid is most effective against.

I hope this is a help to you and that it's in the right ballpark as far as accuracy. Having one of the more expert folks in the Beacon community also comment on this will be a help to both of us.

Best wishes for your new therapy to go well. Please keep us posted on how things go for you.
Mike

[JimNY]

Re: Translation of flow cytometry results

by JimNY on Thu Apr 09, 2015 2:02 pm

There is some good information here in the forum that Multibilly has posted before about these sorts of results. I found two of his posts that I think are especially helpful.

First, in this older thread ("Please help me defining the term 'CD'", started Dec 10, 2013), , he writes:

These are "clusters of differentiation," hence the designation “CD” in CD138+, etc.

Plasma cells have various groups of antigens on their surface. These antigens are flags that help tell your immune system if the cell is a friend or foe. There are many different flags (clusters of differentiation), something like 300 different ones. Healthy plasma cells have their own unique combination of flags. Myeloma plasma cells can have some slightly different flags. One of the more common flags found in myeloma cells is CD138. The overall profile of your flags is what is called your immuno­pheno­type.

When analyzing the cells during your test, some of these flags pop up and others don’t. When they do pop up, they are positive (i.e. CD138+). When they don’t pop up, they are negative (i.e. CD56-).

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.

Your test is just telling you that you have a typical profile of CDs found on the surface of myeloma cells. They aren’t additive like you suggest and each CD is unique. You are showing that you have CD38+ and CD138+ on 11.8% of your marrow cells. Likewise, CD19 and CD56 aren’t popping up and are therefore reported as CD19- and CD56-.

Note that the unique CDs found on the surface of myeloma cells are the basis of how some of the new drugs coming out for myeloma treatment work. These drugs use these specific CDs to target the myeloma cells for execution or to finally go through a natural death process (instead of just living on and on like cancer cells tend to do).

The overall profile of your specific flags (positive or negative) and specifically the levels of certain flags (low or high) can have some some impact on one’s prognosis. This is something that you should discuss with your doctor to get his/her take…but again, don’t freak out and dwell on this.

Also, in this more recent discussion ("Incomplete results on initial bone marrow biopsy", started Jan 27, 2015), 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).

[jane84]

Re: Translation of flow cytometry results

by jane84 on Thu Apr 09, 2015 5:20 pm

Thanks a lot Mike and Jim. I hope Revlimid will be more appropriate, only the future will tell us. There is one thing I am sure of: This forum is a gift.

Good luck to both of you!

[Dr. Adam Cohen]

Re: Translation of flow cytometry results

by Dr. Adam Cohen on Thu Apr 09, 2015 6:06 pm

As mentioned in many of the previous posts, flow cytometry is just a another tool used to identify if there are myeloma cells present in the bone marrow, and to characterize the markers that are expressed on the surface of these cells.

It's hard to interpret your results based on the partial panel you provided, but I suspect there is a small population of myeloma cells that are present in your marrow specimen. There usually is a summary sentence at the end of the flow cytometry report describing the findings that may be more helpful than looking at the individual percentages.

It's important to take the flow cytometry report in the context of the entire bone marrow biopsy report. Myeloma cells are often lost during the processing for flow cytometry, so the percentage of myeloma cells in the marrow is often under-represented by flow cytometry, and it's more accurate to use the percentage on the biopsy or aspirate specimen.

Finally, at this time there is no good evidence that particular markers (or "CD" antigens) on the surface of myeloma cells predict for prognosis or for response to currently available therapies. However, there are new drugs in development, such as daratumumab or elotuzumab, that do recognize specific markers on myeloma cells, and as more of these types of drugs (called mono­clonal antibodies) become available, identifying the particular markers on a patient's myeloma cells may become more important in the future.

Hope this helps!

[jane84]

Re: Translation of flow cytometry results

by jane84 on Fri Apr 10, 2015 1:36 pm

Thank you Dr. Cohen. I will ask for a full report during my next visit.