The stem cell transplant is a process aimed at replacing the older and damaged stem cells with healthier ones. The intravenous infusion of healthier stem cells can produce new blood cells. Patients suffering from leukaemia and multiple myeloma are main beneficiaries of stem cell treatment. This medical procedure is also helpful in treating patients with sickle-cell disease, lymphoma, myelodysplastic syndrome, Ewing's Sarcoma, etc. Since there lies a possibility of development of complications, stem cell therapy is used only in life-threatening situations.

Types of Stem Cell Transplant

There are basically two methods of stem cell transplantation, i.e., autologous and allogeneic. The autologous method is used for collecting stem cells from the patient's body itself. In case of allogeneic transplant, transfer of stem cells takes place between a donor and a recipient.

• Autologous Transplant: In autologous transplantation, the cells are sourced from the body of the patient itself. Collection of cells is done at a time when the body is not suffering from any disease. Pelvis bone is the preferred choice for collecting stem cells from bone marrow. The process of extracting these cells is referred to as marrow harvest. Prior to infusion of blood into the body, it is kept in a freezer.
• Allogeneic Transplant: In this method of transplant, cells taken from a donor are collected and transferred to the recipient’s body. For the stem cell transfer to be successful, the Human leukocyte antigen (HLA) type of donor's tissues should match with that of the recipient.

Stem Cell Transplant Procedure

The first step in the process of stem cell therapy is removal of bone marrow cells by means of irradiation. In case of autologous method, healthy cells are first removed from the body (before irradiating the body). The abnormal or affected cells of bone marrow get destroyed during irradiation. The process of irradiation prepares the body for infusion of newer and healthier stem cells. The stem cells can be collected either from bone marrow, umbilical cord or simply from the blood stream. Amniotic fluid is also one of the sources of these cells. Nowadays, bloodstream is the commonly used source to obtain stem cells the process of collecting cells from blood is known as aphaeresis. Stem cells are transferred to the patient's body by means of intravenous infusion. These cells then, travel to bone marrow and initiate the process of blood cell formation. It takes several weeks for the transplanted stem cells to multiply and grow in the bone marrow. The immune system starts functioning normally once these cells get properly established in the new setting.

Stem Cell Transplant Side Effects

A person who has undergone stem cell therapy is at a high risk of infections. There are chances of contracting the Graft-versus-host disease, veno-occlusive disease, mucositis, etc. The main reason for patients becoming vulnerable to infection is the absence of enough white blood cells in the body. In order to overcome the problem of low immunity, patients are treated with antibiotics. Oral carcinoma is one of the medical conditions that may develop in the patients. The mortality rate in the patients is over 10% it is the main reason behind the use of stem cell treatment only in critical or life-threatening situations.

Graft-versus-host Disease

This disease is caused as a result of allogeneic transplantation. In the graft-versus-host disease, the newly infused donor cells attack recipient cells. This disease can occur even if the HLA of donor and recipient match with each other.

Veno-occlusive Disease

Blockage of veins present in liver is the main symptom of veno-occlusive disease. Increase in the size of liver and weight gain are other symptoms. This disease develops as a result of complications resulting from chemotherapy treatment.

The stem cell transplant procedure holds potential to cure many health problems. This treatment method also has a lot of side-effects. So, it needs to be used far more carefully than other treatment measures.