[Dr. Jonathan Kaufman]

Re: Bone marrow plasma cell percentage at diagnosis?

by Dr. Jonathan Kaufman on Sat May 31, 2014 3:28 pm

Hopeful27,

This is a great question as this can be very confusing. I agree with dnalex, that it shouldn't be considered "infected". The term we typically used is "involved". An individual without myeloma or other plasma cell disorders would typically have less than 5% plasma cell in the marrow. That is of all the cells (nucleated cells to be precise) in the marrow, 5% are plasma cells. It doesn't mean 5% of the total space in the marrow.

By definition, patients with MGUS will have less than 10% plasma cells in bone marrow. The average percentage of plasma cell when patients are newly diagnosed can vary widely. It is common to have 30-50% involvement. Some patients have a much higher percentage, up to 100%.

What makes it somewhat confusing is that the bone marrow biopsy report will have different percentages based on the different tests. The flow cytometry routinely underestimates the true percentage. The report will also tell the percentage for the aspirate (the liquid part of the biopsy) and the core biopsy itself (the intact part of the sample). When we discuss percentages, we usually report the highest value, whether that's in the aspirate or the core biopsy.

I hope this helps.

Best wishes,

Jlk

[Ian]

Re: Bone marrow plasma cell percentage at diagnosis?

by Ian on Sat May 31, 2014 11:46 pm

Thanks, Dr. Kaufman, for a very helpful explanation. I learned a lot from it.

[Julie MM]

Re: Bone marrow plasma cell percentage at diagnosis?

by Julie MM on Sun Jun 01, 2014 5:06 pm

I was 67% at diagnosis. Then 10% after six months of Revlimid and dexamethasone. After Cytoxan, melphalan and ASCT I reached CR and 0%! Then after 1.5 yrs Revlimid maintenance, about 9 months no treatment, I relapsed at 15%.

Have been back on Revlimid and dex. Numbers coming down again

Best of luck to everyone!

[Gidtup]

Re: Bone marrow plasma cell percentage at diagnosis?

by Gidtup on Sun Jun 01, 2014 8:00 pm

Mine was 26%. After SCT it was 2%.

[morrow1022]

Re: Bone marrow plasma cell percentage at diagnosis?

by morrow1022 on Sun Jun 01, 2014 8:24 pm

85% in June when first diagnosed. Six months later after RVD was in remission.

[ScottP FL]

Re: Bone marrow plasma cell percentage at diagnosis?

by ScottP FL on Mon Jun 02, 2014 5:34 pm

Eighty percent (80%) at diagnosis, then normal levels after Revlimid, Velcade, and dexamethasone (RVD) and a stem cell transplant.