[Nanette]

Stem Cell Transplant Lite

by Nanette on Mon May 10, 2010 8:54 pm

Easing bone marrow transplants to widen their use

By Lauran Neergaard (AP) - May 10, 2010 - Washington - Bone marrow transplants are undergoing a quiet revolution: No longer just for cancer, research is under way to ease the risks so they can target more people with diseases from sickle cell to deadly metabolic disorders.

The old way: High doses of radiation and chemotherapy wipe out a patient's own bone marrow before someone else's is infused to replace it, hopefully before infection strikes. (more)

Wow! Interesting. Modern medicine never ceases to amaze me.

"The old way: High doses of radiation and chemotherapy wipe out a patient's own bone marrow before someone else's is infused to replace it, hopefully before infection strikes.

The new way: Rather than destroying the patient's bone marrow, just tamp it down enough to make space for the donated marrow to squeeze in alongside and a sort of twin immune system takes root. It's what doctors taking a page from mythology call "mixed-cell chimerism" — patient and donor blood and immune cells living together to improve health."

[Pat Killingsworth]

Re: Stem Cell Transplant Lite

by Pat Killingsworth on Tue May 18, 2010 12:09 pm

"Transplant Lite" sounds like what is called a "mini-allo" SCT. But isn't there a problem with host/graph disease, with both immune systems in place?

[Beacon Staff]

Re: Stem Cell Transplant Lite

by Beacon Staff on Tue May 18, 2010 12:51 pm

Thanks, Nanette, for pointing out this article. We contacted a couple of myeloma experts about this news. They confirmed that the transplant procedure described in the news article is typically referred to as a mini-allo or non-myeloablative allo transplant.

Dr. S. Vincent Rajkumar of the Mayo Clinic wrote in response to our questions:

1. Do you think the hybrid immune system described in this news article has the potential to be superior to the immune system resulting from a traditional bone marrow transplant? Why or why not?

Not sure. The reason why allogeneic transplants have not worked as well in myeloma is not just due to lack of efficacy, but due to toxicity from graft versus host disease. In "nonmyeloblative" allogeneic transplants (also referred to as "mini" allogeneic transplants), it is true that the patient's marrow is not destroyed, but the problem of graft versus host disease remains. The studies so far are not conclusive, and although we have hope, we do not recommend these transplants in general outside a clinical trial setting for most patients.

2. Why might the new procedure be safer and/or more effective than standard autologous and allogeneic transplants?

Nonmyeloablative transplants are not safer than autologous transplants. They are safer than conventional allogeneic transplants. So far, we do not have clear data that allogeneic approaches (either conventional or non-myeloablative) are superior to autolgous transplants. Results of a large US study are expected later this year and may answer this question.

3. Do you think that this new procedure may be applicable for myeloma patients? Please explain.

Yes, it may be. But until we know its safety and efficacy relative to other good treatment options for myeloma, it is prudent to perform these primarily in the context of clinical trials.

Dr. Sagar Lonial from Emory Winship Cancer Institute wrote, "Any allo transplant (transplant from a donor) is associated with a high risk of complications, and given the low risk of an auto transplant and the plethora of new drugs, i think it is a tough sell to use an allo transplant for myeloma."