MS: Stem Cell Transplant

Hematopoietic stem cells
A stem cell is a type of cell in our bodies that has the potential to develop into a variety of other cell types. One type of stem cell, called the hematopoietic stem cell, can develop into any of three different types of blood cells: red blood cells, white blood cells, and platelets. White blood cells are an important part of our immune system and are the part that is most important to the discussion here.

Researchers are exploring the use of hematopoietic stem cell transplants to treat MS. Scientists believe that MS is an autoimmune disease, which means that the immune system attacks the body's own tissues. In the case of MS, the body attacks the protective myelin coverings of the nerve cells, causing nerve damage. A stem cell transplant may help treat MS by giving the person a "new immune system" that would hopefully be less likely to attack the body's myelin.

How a stem cell transplant works
A stem cell transplant is a major medical procedure that is done in a medical center under the supervision of experienced health professionals. First, hematopoietic stem cells are collected from the person with MS. There are two ways to get the stem cells: from the bone marrow (the spongy centre of the bone; this is called a bone marrow transplant) or from the blood (this is called a peripheral stem cell transplant). Medications may be given to increase the production of stem cells before they are collected. This type of hematopoietic stem cell transplant is called "autologous" because the person is receiving their own stem cells, rather than stem cells from a healthy donor. The most common type of transplant used in people with MS is an autologous peripheral hematopoietic stem cell transplant.

Next, the person is treated with immunosuppressive medications (medications that decrease immune system activity) and radiation to "wipe out" the old immune system cells. Then the hematopoietic stem cells are returned to the person's body by injecting them into a vein. The stem cells then move into the bone marrow, where they begin to make new red blood cells, white blood cells, and platelets. This is called "engraftment," and takes about 2-4 weeks. It will take a number of months for the immune system to recover fully. Until it does, the person is at an increased risk of infection. When the new white blood cells have formed, they will become part of a "new immune system" that may be less likely to attack the myelin.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/MS-Stem-Cell-Transplant

Currently, stem cell transplants are an experimental treatment for MS. We know that they have the potential to help treat MS, but that the procedure can have a number of health risks. Research is ongoing to determine whether stem cell transplants are safe and effective.

Scientists first realized that stem cell transplants may work for MS when they discovered that MS patients, who underwent stem cell transplants as part of their cancer treatment, had a noticeable improvement in their MS. This, plus promising animal studies, led to more interest in studying stem cell transplants for people with MS.

Who's had a stem cell transplant?
Worldwide, more than 600 people with MS have had stem cell transplants as part of clinical studies. These studies have shown that the transplants may help delay disease progression, improve disability scores, reduce the number of relapses, decrease nerve cell inflammation, and reduce brain lesions. The hematopoietic stem cells also showed signs of moving into the brain and forming or protecting new nerve tissues. However, these benefits did not come without risks. The mortality (death) rate from stem cell transplants is approximately 1.3%. Many of these deaths were due to infection, bleeding, or disease progression. Another possible risk of transplant is graft versus host disease (GVHD). GVHD occurs when the transplanted cells attack the tissues of the recipient (the person receiving the transplant). It can lead to skin rashes, liver damage, and intestinal damage, and it may be fatal.

Studies
The Canadian MS/Bone Marrow Transplant Study Group is conducting a number of studies of stem cell transplants for people with MS. They have found that the transplants may decrease myelin destruction, which could help slow down the progression of MS.

Since most of the studies of stem cell transplants in MS have not been comparative (that is, they have not compared the transplant to another accepted treatment), comparative studies are now planned or ongoing. Also, many of the existing studies have been done in people with primary or secondary progressive MS rather than relapsing-remitting MS. Early studies in relapsing-remitting MS suggest treatment responses are better and longer in patients who received transplants during the relapsing-remitting phase than in those who received them in the secondary progressive phase.. In general, larger-scale comparative studies in people with all types of MS are needed before stem cell transplants can become a widely used treatment for MS.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/MS-Stem-Cell-Transplant

Stem cell transplants have shown some promise for treating MS. However, there are many unanswered questions. Here are some of the issues and questions for future research.

Early treatment
Usually we think of inflammation as a bad thing for people with MS. Inflammation can lead to nerve damage. However, some evidence also suggests that inflammation may actually help protect the nerves too. Early in the disease, inflammation leads to damage, and it is here that stem cell transplants may be the most beneficial. However, because they are still experimental, they have only been tested in people with more advanced and severe disease, usually in those with secondary progressive MS. So we don't know how well they will work in early disease, where they may do the most good.

A long-lasting cure?
Another research question with autologous (using the person's own cells) stem cell transplants is whether the benefits in treating MS will really be a long-lasting cure or will offer only short-lived relief of symptoms. Because the transplants are using the person's own cells and putting them back into the same environment, there is a chance that whatever caused the MS will eventually come back to attack the new cells as well. Longer-term studies will help answer this question.

Other areas of study
Researchers will also be looking for ways to reduce the mortality (death) rate from stem cell transplants. The morbidity and mortality related to the treatment have been decreasing as there is more experience with it. The current mortality rate is estimated at 1.3%.  

Studies in mice have shown that transplanted brain stem cells can turn into cells that add new myelin coverings to nerve cells. Could this work in people with MS? More human studies are needed to find out.

Future studies will also examine the safest and most effective treatments to wipe out the immune system before the transplant, how to reduce the risk of infections and other transplant complications, and which MS patients are most likely to benefit from a transplant.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/MS-Stem-Cell-Transplant

Three sources of stem cells
The controversy surrounding stem cell research is more about where the stem cells come from than what they are being used for. There are 3 types of stem cells, based on where they come from: adult, fetal, and embryonic.

Adult stem cells are found in the bodies of adults, often in the blood and bone marrow. These are the type of stem cells that are used in stem cell transplants for people with MS. Adult stem cells can be collected by taking blood or by using a needle to remove bone marrow, usually from the hip bone.

Fetal stem cells are found within a fetus, which is a developing baby aged 8 weeks or older. They can be collected from the placenta or the umbilical cord blood after birth. They may also be collected from a fetus that has been aborted.

Embryonic stem cells come from a newly fertilized egg that is six to eight days old. These stem cells are special because they can develop into any kind of cell within the body. Fetal and adult stem cells are more specialized – they can only divide into certain types of cells. For example, hematopoietic stem cells develop into blood cells. Embryonic stem cells may be harvested from leftover fertilized eggs from in vitro fertilization clinics.

What is – and isn't – controversial
The use of fetal and embryonic stem cells for research and treatment is where most of the controversy and emotion lies. Harvesting adult stem cells has relatively low risk to the donor, and does not destroy an embryo or fetus – it simply collects some of the adult's cells, which the body will quickly replace. Using embryonic stem cells means destroying the embryo. Those opposed to creating extra embryos with the knowledge that some of the embryos will be discarded or used for research instead of being implanted in a woman's uterus may also be concerned about embryonic stem cell research. Using fetal stem cells from a terminated pregnancy also raises a number of ethical issues. Those opposed to abortion are concerned that finding a use for the terminated fetus may encourage abortion. On the other hand, those not opposed to abortion may feel that the terminated fetus should be used for medical research or treatment.

Since stem cell transplants for MS use adult stem cells, the stem cell controversy is less of an issue for this treatment.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/MS-Stem-Cell-Transplant