What Causes an Enlarged Spleen in Patients
with MPNs?
Recorded on: June 2, 2014
Ross Levine, MD
Laurence Joseph Dineen Chair in Leukemia Research
Memorial Sloan Kettering Cancer Center
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Dr. Levine:
So what causes an enlarged spleen for patients who have myelofibrosis, polycythemia vera and essential thrombocytosis?
What we know is that the bone marrow, which is normally where blood cells reside, becomes full of scar tissue, no different
than if you had a scar after an injury if you were playing a sport or something else. And the challenge is then where do the
cells go.
And it turns out that the other place that the blood cells can go and reside and do their job is the spleen. And so the cells
appear to exit the bone marrow and go to the spleen. And the problem is they then grow and like the spleen so much that
they overgrow, and they actually make too many cells and they cause big spleens that cause symptoms. Whereas, in
normal patients who don't have scarring in their bone marrow, the cells never leave the bone marrow and don't go to the
spleen.
So we really believe that it's a movement of cells from the bone marrow to the spleen. And again, drugs like JAK inhibitors
and other therapies appear to reverse that effect, and you get this reduction in the size of the spleen and a reduction in the
normal—a reduction in the number of blood-forming cells in the spleen and hopefully over the long term a reduction in the
scarring in the bone marrow.
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.