DUBSET positive

[Jenny2020]

Hi. Does anyone know what SUBSET positive means in lamen terms? I was Subset positive for cd10,cd23,cd 5 on bmb. Just don’t understand the terminology SuBset

[Pokerguy]

Hello Jenny, I believe the subset reference means that those markers are positive. I attached a communication from Cajun Jeff who puts most of it in laymen’s terms. I too have positive CD5 & CD23 and all this stuff is new and daunting at first.......CajunJeff lays it out and more eloquently than I could ever, here goes:

“In the interest of full disclosure, I have no science background. To the contrary, science was my worst subject in high school. So when I was diagnosed with cll four years ago and read up on it, I was immediately overwhelmed with terms like 13q, CD 38, monoclonal antibodies and mutated IGHV. When my doctor told me my beta2 microglobulin was high, he might as well have been speaking Chinese to me.

It has taken me many years to have some rudimentary understanding of all this. I think I would have understood it faster if I had started out with some basic understanding of cell biology and how cancer works. Cancer is simply a group of diseases that involve abnormal cell growth. For us with cll, its blood cells gone bad, more on that later. First we have to know what a cell is.

Cells (from latin word cella meaning small room) are the tiny building blocks of all life. Cells are very complicated little blocks, but more simply put are a gel like material with a nucleus surrounded by a membrane. We have different types of cells like skin cells, brain cells, bone cells, stem cells and blood cells. We have about 50 trillion cells at anyone time that live and die, or at least our normal ones do. Would you believe we have about two million red blood cells die each second?

For any number of reasons, known and unknown, our cells can turn abnormal and start multiplying and stop dying like normal cells are programmed to do. That is cancer. If our brain cells go bad, we get brain cancer. If our skin cells go bad, we get skin cancer. If our blood cells go bad, we get leukemia.

In our blood we have cells that perform different functions. Red blood cells bring oxygen to our organs. Platelets keep us from bleeding to death. White blood cells are the little soldiers of our immune system that fight infections. Cll is a disease of our white blood cells.

To make it more complicated, we have different types of white blood cells that perform different functions, like having a navy, army and air force in our blood. We have five main types of white blood cells, the two we most talk about with cll are lymphocytes and neutrophils. Lymphocytes (b cells) help fight viruses, our neutrophils help fight bacterial infections.

Cll is a cancer where our marrow makes too many lymphocytes. It is often diagnosed incidentally when we have a blood test which shows our wbc is high. But its not all our white blood cell types that are high with cll. Specifically its our lymphocytes that are high. That's why you might read so many on here discuss their absolute lymphocyte count.

Put another way, cll is when our lymphocytes go bad, multiply and will not die. Instead of living and dying like our healthy cells do, they just live on and crowd out our good cells. But how do our doctors know if our lymphocytes are cll? Okay, that's even more complicated yet, I hope I am not losing you.

We have to go back to cell biology to understand this. Remember that cells are just these little living building blocks surrounded by a membrane. As it turns out, there are all kinds of molecules that are on the surface of our cells that regulate our cells in different ways, including how our cells live and die.

Scientists have given these molecules names to distinguish them. Ever hear of CD38, CD19 and CD20? That's just the name of some of these molecules (regulators) that can live on our cll cells. CD stands for cluster of differentiation. Really? Seems like more of a cluster you know what to me. Scientists call these CD things "markers". Think of them as fingerprints.

Without getting too complicated, our cll has unique markers (molecules on the cell surface of our lymphocytes gone bad), that identify the cells as cancerous lymphocytes. Some of you have heard of flow cytometry. This is just a test they use to look for these markers. Cll cells usually "express" CD5, CD19 and CD20 molecules on their surface. If a molecule is over expressed, that just means there are more than there should be, under expressed means less than normal. Other types of leukemia may over express other CD markers. Think of them as fingerprints doctors use to see what type of leukemia we have, if we have leukemia at all.

Scientists are using cell biology to help treat us. They try to figure out what surface molecule is keeping our bad cells alive and then create drugs targeting those molecules and programming to let the bad cells die (apoptosis). That's an over simplification, but its generally true scientists focus on these abnormal markers and figure out ways to target them to treat us.

One challenging problem is that some or our remedies have a hard time distinguishing the good cells from the bad cells. Remember we said neutrophils are a type of white blood cell that fight bacterial infections? Well some of the treatments we use to kill our cll lymphocytes also kill our neutrophils. That is called an off target effect. The lymphocytes are the target, not the neutrophils. If we kill to many neutrophils we can have neutropenia, low neutrophils, and we have to be careful to avoid bad bacteria until our neutrophils recover..

Well I have rambled on enough. How all the different drugs work for us is a topic for another day, I am sure this explanation of cell biology has left some more confused than when they started.

And I also defer to the true scientists on here as I do not really understand this stuff on a scientific level and in trying to dumb it down for me to understand, may have gotten some points wrong.

But I think most of this is generally correct and took me a long time to understand, if I really do. If this is helpful to anyone, Ill take a shot at cll treatment options for dummies next”

Hope this helps

[lankisterguy Volunteer]

Hi Jenny,

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Pokerguy and cajunjeff have provided very good answers.

I would like to add a bit more.

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When your hematologist ran the FLOW test on the sample from your bone marrow, they were looking for particular combinations of protiens on your White Blood cells. and when these three ( cd10, cd23, cd 5) were found, that confirmed your cancer is CLL and not something else (like Hodgkins Lympoma or Follicular Lymphoma). So those three markers were called a subset.

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SNIP: emedicine.medscape.com/arti...

Peripheral blood flow cytometry is the most valuable test to confirm a diagnosis of chronic lymphocytic leukemia (chronic lymphoid leukemia, CLL). It confirms the presence of circulating clonal B-lymphocytes expressing CD5, CD19, CD20(dim), CD 23, and an absence of FMC-7 staining.

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Len