Marrow Cellularity %?
 

I have a “theoretical” question, but there is a reason I am asking it…

I have read that it is possible to compute a “normal” per cent of bone marrow cellularity by subtracting a person’s age from 100. For example, I am 46 years old, so 100-46 = 54%. In other words, a person my age with normal cellularity would expect to have ~54% active blood making cells in the bone marrow.

Does this mean that as everyone ages, we all will eventually have hypocellular bone marrow (if we live long enough)? Let’s say I am 90 years old – so now am I expected to have 10% cellularity? This doesn’t seem right. I imagine that this general guideline (100 – age = %normal cellularity) is a general guideline and does not hold up for all ages.

The reason I ask is that one of my doctor’s described my particular situation of slowly declining cellularity as if my bone marrow were just slowly “wearing out.” I wondered if, as we age, our marrow does indeed wear out – but not usually at (or anywhere near) age 46.

Any thoughts on this?

That's a very interesting question. I have hypocellular bone marrow too but don't know the percentage. I have often wondered if the 100 minus age was accurate in all age groups and diseases.

Chirley

David,

The general guideline for computing marrow cellularity as "100-age=percent" applies even at advanced age. So, yes, a 90-year-old would be expected to have something in the area of 10% cellularity. In fact, the rate of decline in cellularity seems to accelerate after age 70. I have heard doctors describe the effects of MDS on cellularity as making it seem as though the bone marrow is just wearing out.

There is a chart on page 9 of Bone Marrow Pathology by Barbara J. Bain, David M. Clark, and Irvin A. Lampert that can be seen at Google Books. It shows the expected decline in cellularity of normal bone marrow as people age.

Hope this helps.
Ruth

when i was diagnosed that formula was how my dr. described it to me. to help me understand she said i had the bone marrow of a 90 yr old. i'm 29 with less than 10% cellularity. this whole process has been such a learning experience!

Ruth?
 

Soo...if we are all naturally experiencing bone marrow cellularity decline, and I am starting (at this point in my life) at only 10%....doesn't seem to reason that my body will at one point just give up making bone marrow or it will at least decrease even further? Or do people with AA bodies differ? A grim thought I suppose, but I thought it was a good question :)

Deanna16, your question is a good one that you might best ask of your doctor. I think if your cellularity were to decrease further you would have to move from "watch and wait" to some sort of immunosuppressive treatment designed to improve your marrow function.

Ruth

that's what i thought you'd say :D thank you, i will see how the dr. responds next time i go...in the past her answer has been similar to yours