Posted on 12/17/2006 10:12:07 PM PST by Coleus
Stem cell therapy with bone-marrow derived mesenchymal stem cells appears promising to treat graft versus host disease (GvHD), researchers said at the 48th annual meeting of the American Society of Hematology (ASH).
Katarina Le Blanc, MD, PhD, Karolinska University Hospital, Huddinge, Stockholm, Sweden, and colleagues transfused mesenchymal stem cells into the gut and liver of a small boy with severe, refractory, life-threatening GvHD as a "last resort" treatment. To their delight, the researchers saw a "remarkable" anti-inflammatory and immunomodulatory response, Dr. Le Blank said in a presentation on December 12th.
It has been known for some time that bone marrow contains not only hematopoetic stem cells but also mesenchymal stem cells, which are the stem cells of connective tissue. These cells provide the stroma usually composed of connective tissue that hematopoetic stem cells live on in the bone marrow, and they also give rise to bone, cartilage, muscle, and connective tissue, Dr. Le Blanc explained.
Mesenchymal stem cells also appear to have immunomodulatory and anti-inflammatory effects, and are proven to inhibit T-cell alloreactivity in vivo. Therefore, the GvHD characteristic of attacking the host body's cells is blocked by the injection of these stem cells.
Spurred by the success of their first MSC infusion, Dr. Le Blanc and her colleagues gave varying doses of MSC derived from bone marrow to 52 patients with severe grades III or IV acute GVHD. The stem cells were donated from HLA-identical sibling donors, haploidentical donors, and human leukocyte antigen (HLA)-mismatched donors. "The HLA match does not seem to be as important with mesenchymal cells as it does with hematopoetic stem cell transplantation," noted Dr. Le Blanc.
Results were successful overall. No side effects were seen after infusion.
Of the 40 patients treated, 19 had complete responses, nine showed improvement, 7 patients did not respond, 4 had stable disease, and 1 patient could not be evaluated due to short follow-up. In addition, 21 patients remain alive from 6 weeks to 3.5 years after MSC transplantation. "Mesenchymal stem cells have immunomodulatory and tissue repairing effects and should be further explored as treatment of severe acute GvHD in prospective randomized trials," Dr. Le Blanc said. [Presentation title: Mesenchymal Stem Cells for Treatment of Severe Acute Graft-Versus Host Disease. Abstract 753]
Specific Stem Cells Reduce Graft-versus-host-disease Among Stem Cell Transplant Recipients
According to results presented at the 2006 annual meeting of the American Society of Hematology (ASH), mesenchymal stem cells appear to ease graft-versus-host disease among patients who have received a stem cell transplant.
Allogeneic stem cell transplant is type of a therapeutic approach used for the treatment of various types of cancer. With this approach high doses of chemotherapy and/or radiation therapy are utilized and followed by the infusion of donor stem cells. These high doses are associated with greater side effects—particularly low levels of blood cells—than more moderate doses of therapy. Allogeneic stem cell transplants are used to restore blood cell levels following high-dose therapy and thus reduce the associated risk of life-threatening infection, bleeding, or anemia. This approach involves the infusion of a donor’s hematopoietic stem cells, which are immature blood cells that mature into the necessary blood cells once they are circulating in a patient’s body.
Another potential benefit of allogeneic stem cell transplant is that the donor stem cells can mount an attack against a patient's cancer cells. Unfortunately, the donor stem cells may also mount an attack against a patient's healthy cells, resulting in a condition called graft-versus-host disease (GVHD), which may be life-threatening. Graft-versus-host disease is often treated with steroids, though it sometimes does not respond to steroids or stops responding. In this event it is referred to as steroid-refractory GVHD. Because steroid-refractory GVHD is a serious condition with a high death rate, researchers are evaluating ways to treat it or reduce its symptoms.
Researchers from Europe recently conducted a study to evaluate the infusion of stem cells among patients with steroid-refractory GVHD. This study included 52 patients who had undergone a bone marrow transplant and had developed steroid-refractory GVHD. Patients were treated with mesenchymal stem cells from a donor. Mesenchymal stem cells are specific types of stem cells that are collected from bone marrow (spongy material inside) and will develop into bone, muscle, cartilage, and connective tissue. They are thought to help suppress the donor's immune cells and reduce the risk of GVHD.
The researchers concluded that treatment with mesenchymal stem cells appears to effectively treat steroid-refractory GVHD that would otherwise have been fatal in a majority of patients who underwent allogeneic stem cell transplants. A subsequent clinical trial to further evaluate this strategy is planned. Patients with steroid-refractory GVHD may wish to speak with their physician regarding their individual risks and benefits of participating in a clinical trial further evaluating this or other promising treatment strategies. Two sources of information about ongoing clinical trials include the www.eCancerTrials.com and the National Cancer Institute (www.cancer.gov). Reference: LeBlanc K, et al. Mesenchymal Stem Cells for Treatment of Severe Acute Graft-Versus-Host Disease. Proceedings from the 2006 annual meeting of the American Society of Hematology. December 2006. Abstract #753.
Could the test subject have benefited from his own stem cells? The article is vague.
Bone marrow transplants are transplanted from other people who are a tissue match.
This wasn't a transplant. They were using bone marrow stem cells to grow replacements for other organs.
Okay, maybe not 'grow' but elicit a response.
Could the test subject have benefited from his own stem cells?
No. In plain English, allogenic means tissue from another person was used for the original transplant, often in the form of that person's stem cells. Leukemia is a good example where you need a bone marrow transplant from someone else. Elements of the graft's immune system attack the recipient in Graft Versus Host Disease.
Interesting. I don't see you as correct here though.
Their hematopoetic, i.e. blood forming, stem cells caused the leukemia, aka a cancer of their blood.
Where do you imply that the initial cells for this article came from?
"The stem cells were donated from HLA-identical sibling donors, haploidentical donors, and human leukocyte antigen (HLA)-mismatched donors. "The HLA match does not seem to be as important with mesenchymal cells as it does with hematopoetic stem cell transplantation," noted Dr. Le Blanc."
The second donor, i.e. the mesenchymal stem cell donor for treating the steroid-refractory GVHD patient. That's what is remarkable about the story. (HLA)-mismatched donors means that donor and recipient had at least one Human Leukocyte Antigen, HLA, i.e. an antigen on a white blood cell, mismatch, but it didn't trigger an immunologic response.
To the contrary, it treated the GVHD caused by the needed transplant.
The donor cannot supply himself (herself)?
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