How manh good B-cells do I have ?: Below is a... - CLL Support

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How manh good B-cells do I have ?

markjeep51 profile image
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Below is a 2019 Flow Cytometry Report, which I really do not understand.

"Based on 7-AAD, CD45/SSC and FSC histograms, viable cell distribution in the sample was 47% lymphoid, 4% monocytic, and 48% myeloid. There is a population of CD19+ B cells (38% of total cells) that express kappa light chain and co-express CD5 and dim CD20 without significant expression of CD10 or lambda light chain. CD5+ T cells are no increased and show a similar size based on FSC. There is no increase in blasts on a CD45/SSC histogram. Gating on cells produced the phenotypes shown above. These findings are consistant with persistence of the patient's previously diagnosed CLL."

My oncologist explained that the % of good (non-defective) B-cells is estimated as follows: 47% ( lymphoid) minus 38% (B-cells with CD19+) = 9% good B-cells. Is this a correct way to estimate the % of good B-cells?

I understand that all B-cells have the marker CD19. The doctors analysis above implies that the B-cell's having the CD19+ marker are the defectived one. Is this a correct understanding ?

I am led to believe that the term " lymphoid" is an obsolute term and has been replaced with the term "lymphocyte", correct ?

I am assuming that the 47% number is the % of lymphocytes, relative to the White Blood Count (WBC), correct ?

I am assuming that the 48% myeloid number is the approximate % of neutrophils, relative to the WBC, correct ?

I am assuming tha the 38% number is the % of lymphocytes having the CD19+ marker attached to its surface, correct ?

I am trying to simple get a basic understanding of what my Flow Test is saying. Hoping someone can shed some light.

PS: Currently on watch & wait, deletion 13q14.3, ZAP-70 negative, mutated IgVH. Have one inch lymph node on my neck but feel fine otherwise.

Thanks

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markjeep51
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9 Replies
gardening-girl profile image
gardening-girl

mark, since no one has yet responded to your questions, I'll give it a try, putting your questions in italics.

My oncologist explained that the % of good (non-defective) B-cells is estimated as follows: 47% ( lymphoid) minus 38% (B-cells with CD19+) = 9% good B-cells. Is this a correct way to estimate the % of good B-cells?

No, there are a couple of things wrong with this. First of all it is the B-cells that express both CD19 and CD5 that are your kappa light chain expressing CLL cells. Even subtracting the 38% CD19/CD5 B-cells from the 47% lymphoid cells will not give you the % normal B cells. You need to know the number of CD19 cells without CD5 to know that. The 9% of cells that your doctor referred to as being the % of normal B-cells leaves out the fact that normally 80% of lymphocytes are T-cells with a smaller number of NK cells. Using the 80% number, 80% of 9% equals 1.8, which would mean that 1.8% of your B-cells are normal. You need to forget about % and track the absolute numbers!

I understand that all B-cells have the marker CD19. The doctors analysis above implies that the B-cell's having the CD19+ marker are the defectived one. Is this a correct understanding ?

No, CD19 is expressed on all B-cells. It is the additional presence of CD5, normally a T cell marker, on a CD19 B-cell that leads to a CLL diagnosis.

I am led to believe that the term " lymphoid" is an obsolute term and has been replaced with the term "lymphocyte", correct ?

Probably not. Lymphoid is the term used to refer to cells of the lymphoid lineage; lymphocytes (B-cells & T-cells) & NK cells. Just like Myeloid is used to refer to cells of the myeloid lineage; neutrophils, macrophages, dendritic cells, eosinophils and basophils.

I am assuming that the 47% number is the % of lymphocytes, relative to the White Blood Count (WBC), correct ?

Yes!

I am assuming that the 48% myeloid number is the approximate % of neutrophils, relative to the WBC, correct ?

Yes, as long as you realize it is an approximate number. They are the most numerous of the myeloid lineage cells in this analysis.

I am assuming that the 38% number is the % of lymphocytes having the CD19+ marker attached to its surface, correct ?

38% is the number of lymphocytes that have CD19+ and CD5+. To quote your report:"There is a population of CD19+ B cells (38% of total cells) that express kappa light chain and co-express CD5..."

Wonderful that you are on watch and wait. With your deletion 13q14.3, ZAP-70 negative, mutated IgVH status you are likely to remain treatment free for a very long time, and indeed may never need treatment!

Let me know if I missed anything and don't hesitate to ask away. There are lots of us here with years of experience, mucking our way through the terminology, as well as wending our way through various treatments.

gardening-girl

PS- I probably have said this first. Pay attention to cell counts, not percents. Your report should have given you numbers for CD19 cells, CD19/CD5, neutrophils, etc. It is these numbers that you need to keep track of, not percents!

markjeep51 profile image
markjeep51 in reply to gardening-girl

WOW !!! What a great response. You really cleared up a lot of questions I had. Great great job. Thank you very much for taking the time with me. Mark

markjeep51 profile image
markjeep51 in reply to gardening-girl

Just to make sure I understand your methodology, I will submit my exam paper as follows:

What I will be doing is (a) using your methodology above, (b) taking into account my 2019 Flow Cytometery Test, and (c) applying my July 2021 blood test, to calculate an absolute estimate count of my good & bad B-cells and T-cells.

My July 2021 blood results are 25.61 k/cmm WBC, 16.13 k/ccm lymphocyte, 8.96 k/ccm neutrophils, IgG 343mg/dL, and 138 k/cmm platelets.

Base on your comments above, my good B-cell count is estimated as follows:

1.8% times 25.61 k/ccm = 1.8% time 25,610/ccm = 461/ccm of good B-cells.

Note that the normal lymphocyte count is from ~1,000 to ~4,800/ccm, which includes both B-cells and T-cells. Using the estimate that B-cells make up ~ 20% of a lymphocyte count, the resulting B-cell range , for a normal person would be ~200/cmm to ~960/cmm (=20% times 4,800). Therefore, I conclude that my good B-cell count of 461 could still be interpreted as being within a normal range.

My defective B-cell count is estimated at 38% times 25,610 = 9,732/cmm.

The number of T-cells is estimaed as follows:

Where 47% times 25,610 = 12,037 ( is the # of both B-cells plus T-cells).

Therefore, the number of T-cells = 12,037 minus 9,732 ( # of bad B-cells) minus 461 ( # of good B-cells) = 1,844/cmm T-cells.

For a normal person, the # of T-cells would be estimated at 80% of the 1,000 to 4,800 lymphocyte range. This equates to 800/cmm to 3,840/cmm. Once again, I conclude that my T-cell count could still be interpreted as being within a normal range.

But due to the complex bio- chemical interactions of CLL and the consequences of having a defective 13q14.3 gene, my immune system is not operating normally; luckily, it is only slowly degrading. Will keep my fingers crossed for more effective treatments someday.

gardening-girl profile image
gardening-girl in reply to markjeep51

Definitely a good effort. I think that you did follow my thinking. However I'm afraid it doesn't work that way when you have changing percents of normal and defective cells.

Let's try doing the same calculation that you did with a starting a WBC approximately double your current count of 25.61 k/cmm. 50/cmm x 1.8% = 0.9 or 900/cmm. According to this way of thinking you'd have more normal B cells than you have now, and with each increase in your WBC you'd calculate more normal B cells. Unfortunately it's not going to work that way. If anything the normal B cell count may decrease with increasing CLL cells.

You are not going to be able to know how many normal B cells you have until you have another flow cytometry test quantitating the CD19+ and CD19+/CD5+ cells. 16.13 k/cmm is a pretty low count, and with your excellent markers, as AussieNeil said, you can anticipate a long watch & wait.

Also, a suggested edit in a few places. When I was following your calculations above, I just about went crazy trying to figure out how you could have 16.13 k/ccm lymphocytes! I asked my husband to help me figure it out and he pointed out that you must have meant 16.13 k/cmm, not ccm! 🤔

And yes, we can all hope for more effective treatments!🙏

markjeep51 profile image
markjeep51 in reply to gardening-girl

My old physics teacher would have shot me for making a mistake on how I illustrated the 'dimensions" of a problem; cmm and not ccm ! Your correct. Thanks for your comments.

PS: I will ask my doctor for the number of polycolonal B cells, as bkoffman suggests. Sounds like the only way to get a snap shot on how any good B-cells I have floating around. Mark

gardening-girl profile image
gardening-girl in reply to markjeep51

Yes, the polyclonal B cells will be the CD19+ cells that don't also express CD5+.

AussieNeil profile image
AussieNeilAdministrator

Hi Mark,

You are fortunate in having your oncologist explain this to you and you've nearly got it!

Lymphoid and Myeloid refer to the stem cell lines from which all our blood cells are made in our bone marrow. B, T and NK lymphocytes are produced from the lymphoid stem cell line and every other blood cell type (not just neutrophils) are produced from the myeloid stem cell line, per the image below.

CD19 markers are found on not just CLL cells, but all B cells (except the mature plasma cell form). See: abcam.com/primary-antibodie...

CLL cells are identifiable by a specific pattern of CD expression, plus they either have just a kappa or lambda light chain in their B cell receptor.

So what differentiates your CLLs cell from your healthy B cells is that unique CD pattern, plus the kappa light chain per "There is a population of CD19+ B cells (38% of total cells) that express kappa light chain and co-express CD5 and dim CD20 without significant expression of CD10 or lambda light chain." Another member might have just lambda light chain expression in their CLL cells.

That 9% of good lymphocytes will be B, T and NK cells. Before you developed CLL, about 5 to 15% of your lymphocytes would be B cells and the rest T (helper and cytotoxic) plus natural killer (NK) cells. The ration of B, T and NK cells is likely disrupted by the influence of the CLL cells on the T cell population.

Keep in mind that the reported percentages may vary depending on the bone marrow sample taken and that CLL cells mainly proliferate in our nodes: healthunlocked.com/cllsuppo... Most importantly, you've got excellent markers, so can anticipate a long watch and wait.

Neil

Hematopoeisis- bone marrow blood cell production from myeloid and lymphoid stem cell lines
bkoffman profile image
bkoffmanCLL CURE Hero

Your doctor can ask the pathologist for the number of polyclonal B cells. Those would be normal B cells and was likely measured, but it often not reported. As others stated, your doctor's explanation is not fully correct and what matters is the absolute count.

markjeep51 profile image
markjeep51 in reply to bkoffman

I will ask my doctor for the number of polycolonal B cell, as you suggest. I'll let you know what happens. Great suggestion. PS: I tried to calculate an estimated number of normal B cells as suggested by the methodology putforth by Gardening-Girl. But as AussieNiel stated, "The ratio of B, T and NK cells is likely disrupted by the influence of the CLL cells on the T cell population". So my assumption of using ~20 % of Lymphocytes are B-cells and ~80% are T-cells may no longer be true. The longer one has CLL , it is unknown to me what trending direction these ratios move in, relative to my specific gene defect.

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