Hematopoietic stem cell transplantation is the process of transplanting multipotent hematopoietic stem cells, mostly from peripheral blood, bone marrow or umbilical cord blood. Hematopoietic stem cell transplantation was first used in the treatment of some types of cancer, but today it is widely used for the treatment of various autoimmune diseases. However, it is important to note that although the United States Food and Drug Administration (FDA) has approved hematopoietic stem cell transplantation (HSCT) for use in the fight against cancer, it does not.
What is Stem Cell Transplantation Used in Treatment?
Stem cell therapies are still in the experimental stage for the treatment of autoimmune diseases. Stem cells are cells that have the ability to transform into various different specialized cells in the body. Stem cell transplantation has been approved for the treatment of various cancers. These include multiple myeloma, leukemia and some lymphomas. In addition, HSCT is used to treat autoimmune diseases in many specialist clinics around the world. Perhaps the most notable of these is multiple sclerosis. An extremely high success rate for this treatment has been claimed but is still considered experimental. HSCT used in the treatment of cancer is not considered an oncological procedure. This is called a hematological process involving the role of blood in health and disease.
There are two types of HSCT. They are allogeneic and autologous.
Allogeneic HSCT: Allogeneic HSCT requires a donor to supply suitable stem cells. Doctors performing such HSCT should ensure that the donor is a suitable match for the recipient. Usually this is a close relative, but other donors that are matched by tissue typing are also used. Proteins known as human leukocyte antigens (HLA) are used in tissue typing. It allows clinicians to compare a person’s blood and tissue type with blood samples from possible donors. In this way, they can check whether the stem cells of a donor match correctly.
Allogeneic HSCT usually requires a donor from the immediate family of the patient. In addition to using stem cells in the blood of a donor, cells in the umbilical cord blood can also be used. Umbilical cord stem cells are less developed than other stem cells, which means they can be transformed into different cell types. This is important because umbilical cord blood stem cells freeze at birth because they do not show any environmental damage or aging. As a result, cord blood transplantation does not require such a high level of tissue matching.
Autologous HSCT: Autologous HSCT avoids trying to find a suitable donor because stem cells are collected from patients. After taking chemotherapy drugs, the cells are cleaned and frozen before being given back to the individual. According to the Russian Pirigov Center in Moscow, the steps of the autologous HSCT are:
• Stem cell stimulation for 4-6 days,
• Stem cell collection for 1 to 3 days
• Chemotherapy for 4 days • Stem cell infusion within 1 day • 8 to 12 days of isolation
How to proceed?
Although therapy is a form of stem cell transplant, stem cells are not the main part of the process. In fact, the key element is the infusion of chemotherapy drugs. There are two types of transplantation processes known as myeloablative and myeloablative. Myeloablative involves the use of high-dose chemotherapy drugs to destroy the immune system. It uses non-myeloablative, lower-dose, more tolerable chemotherapy drugs to suppress the immune system. High doses of chemotherapy are required to treat cancers.
In both procedures, stem cells are transplanted after chemotherapy medications are given to help establish a new and healthy immune system. Low-dose chemotherapy has been found to be successful in dealing with autoimmune diseases such as multiple sclerosis.
Risks and Complications
The donor may be advised to take iron supplements following the procedure to increase red blood counts. Hepatic veno-occlusive disease (VOD) with additional renal or lung abnormalities may develop in humans after taking HSCT. In March 2016, the FDA approved Defitelio (defibrotid sodium) as a treatment for such development. Another risk associated with allogeneic stem cell transplantation is graft-versus-host-disease (GVHD) that occurs when donated cells attack a person’s tissues. The lower the type of tissue between the patient and the donor, the higher the risk of GVHD. Doctors may use medications to reduce the likelihood of infection or GVHD. For a surgical procedure, there is not much risk for donors to worry. In addition, serious complications are rare. Possible complications include:
• Anesthesia reactions
• Nerve or muscle damage
• Transfusion reactions
• Needle placement site injury According to the
American Cancer Society (ACS), donors may experience fatigue, discomfort and pain around the waist and hips for several days after stem cell transplantation. This disorder can be alleviated by over-the-counter acetaminophen such as ibuprofen and non-steroidal anti-inflammatory drugs (NSAIDs). Doctors may recommend that donors take iron supplements until their red blood cell counts return to normal. Many donors can return to their daily routine after resting for 2-3 days. However, in some cases full recovery may take 2 to 3 weeks.
Researches on the use of autoimmune diseases
Different studies on the use of HSCT for autoimmune diseases have reached different conclusions. Canada has reported the results of the clinical study of autologous HSCT as a great success. In this study, it was reported that people with severe disabilities with multiple sclerosis, cycling, walking and even skiing after treatment. This report is an improvement with newspaper headlines around the world.
Other researchers from the University of Basel Hospital in Switzerland have previously addressed the various challenges faced by people with autologous HSCT for the treatment of autoimmune diseases. Their report was published in Pediatric research in February 2012, suggesting that HSCT is associated with significant morbidity and mortality and, therefore, is not yet standard treatment, giving a more cautious view on the use of treatment.
In the future, experts have suggested that new complications may be found in patients treated with HSCT for autoimmune diseases. As a result, they have proposed several preventive measures for those using this treatment method: careful assessment of organ function before HSCT is recommended; Follow-up examinations after HSCT should be adapted to the patient and the type of conditioning in a standard manner.