How Sensitive Are CLL Minimal Residual Disease (MRD) Test Results? | Transcript | Chronic Lymphocytic Leukemia | Patient Power


How Sensitive Are CLL Minimal Residual Disease (MRD) Test Results?

Please remember the opinions expressed on Patient Power are not necessarily the views of our sponsors, contributors, partners or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. That’s how you’ll get care that’s most appropriate for you.

But that's kind of a gross testing.  Yes, you feel better, but I don't know how much leukemic cells you've got in your lymphatics or in some other part of your body.  So there became a—sadly gradual, but it became a process of getting to be more and more sensitive in your testing.  For example, if you take a half gallon of any liquid, dump out the liquid actually, put one black marble in there, fill all the rest of that half gallon with white marbles, that's what we want to test for.  We want to be able to see—a half gallon is about the size of your normal bone marrow, so we want to be able to see if there's one bad cell amongst that.  We can't do that.  

It's just too, too precise, too sensitive a level.  We can though say that you only have a million cells—I know that sounds like a huge number, but when you have in scientific lingo we use numbers, 10 to the sixth, 10 to 10th, 10 to the 12th, you were diagnosed with 10 to the 15th-ish cells in that bone marrow.  We can get down to 10 to the 5th now, 10 to the sixth cells.  That's a huge drop from 10 to the 15th.  That's 10 with 15 zeros after it versus 10 versus nine versus nine zeros after it.  That's a large number of cells.  So, yes, we have gotten more and more sensitive.  

The problem with sensitive testing, which is always the issue, is you tend to get false positives in them so sometimes a number that is barely possible or barely not positive could be somewhat iffy because the tests aren't that wonderful.  

The problem with that also is I can't tell you if you have zero cells or 999,999 cells that are malignant. There's no way I can tell that really consistently at this point in time.  So you have to think of things like, I'm kind of like a diabetic.  It's always there, but as long as I control it I can live a healthy, high-quality life.  Maybe in a few years we'll get more sensitive than that, but right now that's the best we can give you.  

They've gotten much more sophisticated, and he said, well, you're not MRD negative, and I kind of freaked out.  And he said, some day you may need treatment again.  Well, I went many years.  It was 17 years between when I had the initial treatment of FCR and when later, I happened to have Gazyva, or obinutuzumab, and some steroids is what I had, but anyway, that was last year, but it was a long, long time.  So while I was not MRD-negative I lived my life. 

Please remember the opinions expressed on Patient Power are not necessarily the views of our sponsors, contributors, partners or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. That’s how you’ll get care that’s most appropriate for you.

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Page last updated on May 22, 2019