Bone Marrow/Stem Cell Transplantation

Bone marrow transplantation is a medical treatment that replaces your bone marrow with healthy cells. The replacement cells can come from either your own body or from a donor.

This procedure is also known as a stem cell transplant or more specifically, hematopoietic stem cell transplant. It is used to treat certain cancers such as leukemia, myeloma, and lymphoma, as well as other diseases affecting the bone marrow and immune system.

What are Stem Cells and Bone Marrow?

Stem cells are special cells capable of self-replication and transforming into different types of cells required by the body. Various types of stem cells exist at different stages and in different parts of the body.

Cancer and cancer treatments, such as chemotherapy, can damage hematopoietic stem cells, which are responsible for producing blood cells. Hematopoietic stem cells are found in the soft, spongy tissue inside bones, called bone marrow, as well as in the bloodstream. When these cells are damaged, they fail to produce red blood cells, white blood cells, and platelets.

Types of Transplants

There are two main types of bone marrow/stem cell transplants:

1. Autologous Transplant:

In this type, stem cells are collected from your own body. Often, high-dose chemotherapy or radiation therapy is used to treat cancer, but these treatments can also destroy healthy stem cells and weaken the immune system. To prevent this, doctors collect stem cells from your blood or bone marrow before treatment begins.

After chemotherapy, the collected stem cells are reintroduced into your body to help restore your immune system, regenerate blood cells, and fight infections. This procedure is also known as auto-transplant or stem cell rescue.

2. Allogeneic Transplant:

In this procedure, stem cells are obtained from another person, called a donor. After chemotherapy or radiation therapy, the donor’s stem cells are transplanted into the patient’s body. This is known as an allo-transplant.

One benefit of allo-transplants is the “graft-versus-cancer effect,” where the transplanted stem cells help eliminate any remaining cancer cells in the body.

A critical step in allogeneic transplantation is finding a donor match. This is determined by matching the donor’s human leukocyte antigens (HLA), which are proteins in the blood, with those of the patient. Siblings from the same parents often make the best matches, but unrelated volunteers can also be suitable. When the donor’s proteins closely match the patient’s, the risk of severe complications, such as graft-versus-host disease (GVHD)—where healthy transplanted cells attack the patient’s tissues—is reduced.

Recovery Process

The recovery from a bone marrow or stem cell transplant can take a long time and involves several phases, starting with intensive medical monitoring immediately after the transplant. As recovery progresses, regular medical check-ups will be necessary for months or even years.

During the early stages, it is crucial to monitor for signs of infection. Intense chemotherapy before the transplant suppresses the immune system to prevent the body from attacking the transplanted stem cells. It takes time for the immune system to regain normal function, so the risk of infections is particularly high in the immediate post-transplant period.

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