May 7, 2017

Stem Cell Transplant

If you or someone you know has a condition that affects the bone marrow or blood, a peripheral blood stem cell transplant could be the best treatment option. Peripheral blood stem cell transplant entails transplanting new, healthy stem cells into the bloodstream, where the stem cells begin to grow and make healthy blood cells.

Why is a transplant needed?

A transplant is suggested by the doctor when the patient’s bone marrow has stopped producing healthy blood cells needed to battle the blood disorder. Each one of us has bone marrow which is a factory that generates healthy blood cells. A few of these cells from your body can help save a life of a patient with a blood disorder. That’s why these cells are termed as magic cells.

In certain kinds of cancer, such as Leukemia and Lymphoma, the treatment process comprises of high dosage chemotherapy or radiotherapy and even a combination of both in unison, resulting in the patient’s bone marrow being destroyed.

This intensive treatment causes the bone marrow to cease production of blood cells altogether thereby precipitating the requirement of a stem cell transplant to facilitate the creation of blood cells that are imperative to one’s survival and sustenance.

What are stem cells?

Stem cells are the body’s primary cells. All other cells, tissue, organs and bones develop from stem cells.

Stem cells mostly live in the bone marrow (the spongy center of certain bones). Stem cells divide to make new blood cells, which keep our blood healthy. Although unremarkable in appearance, stem cells can perform what have been called “acts of biological resurrection.”

These cells are present in the blood, and have the ability to divide and develop either into a structure that represents their original constitution or alternatively, acquire a new form into a specific cell, with distinct functions and features similar to red blood cells, white blood cells, and platelets. For example, blood stem cells can create red blood cells, which carry oxygen around our body and white blood cells, which help us fight infections.

For us to be healthy, our blood stem cells need to produce exactly the right amount of each type of blood cell.  All of the blood cells in your body start out as young (immature) cells called hematopoietic stem cells or peripheral blood stem cells. These stem cells are blood forming cells. Once blood cells mature, they leave the bone marrow and enter the bloodstream.

Stem cell transplants are used to give back stem cells when the bone marrow has been destroyed by disease, chemotherapy, or radiation. Depending on where the stem cells come from, this procedure may be called:

  • Bone marrow transplant (BMT)
  • Peripheral blood stem cell transplant
  • Cord blood transplant

They can all be called hematopoietic stem cell transplants.

Your donor stem cells could come from:

  • Your brother or sister
  • An unrelated donor
  • An umbilical cord (the cord that connects a baby in the womb to its mother)

What are different types of transplant?

In both peripheral blood stem cell transplant and bone marrow transplant, stem cells are transplanted but they are collected from the donor in different ways.

In a peripheral blood stem cell transplant, the stem cells are collected from the donor’s blood. The process is similar to the blood donation process and it is called peripheral blood stem cell collection. Up to 90% of donations happen this way.

In a bone marrow transplant, the stem cells are collected from the donor’s bone marrow.  This involves a small surgical procedure, using a needle to collect the bone marrow from a bone in the pelvis under general anesthesia.

Generally transplants are classified into three broad categories:

  • Autologous: These stem cells originate from the patient itself and are harvested prior to the chemotherapy treatment
  • Allogeneic: These cells are collected from a donor whose tissue type matches the patient’s. This may either be from a family member (usually a sibling), or from an unrelated person, also referred to as matched unrelated donor (MUD)
  • Syngeneic: Also a form of allogeneic transplant, wherein stem cells are extracted from the patient’s identical twin. Such methodology eliminates the graft versus host disease (GvHD) threat altogether (where the recipient may reject the transplanted cells).

How does the transplant work?

The way a transplant works depends on the type of transplant and the disease that the patient is fighting. If the patient has a blood disorder and the patient’s immune system isn’t working properly, the aim of the transplant is to give the patient new healthy blood and immune system.

In a typical stem cell transplant for cancer, very high doses of chemotherapy are given to the patient sometimes along with radiation therapy. This treatment also kills the stem cells in the bone marrow. Soon after treatment, the donor stem cells are given to replace those that were destroyed. The stem cells from the donor are given into a vein, much like a blood transfusion and help the patient form a new immune system. The new immune system recognizes any remaining cancer cells in the body as foreign and attacks them. Over time they settle in the bone marrow and begin to grow and make healthy blood cells. This process is called engraftment.

The harvesting of stems cells can be either done via direct extraction from the bone marrow or through filtering the blood stream after a hormonal injection (a process called apheresis). The stem cells then may be used right away for the transplant or stored and frozen in liquid nitrogen until needed.

The foremost and predominant prerequisite of a successful stem cell transplant is to find a donor whose organ and tissue are an equivalent and identical match to that of the recipient patient. In order to do this, a Human Leukocyte (HLA) test is conducted. It facilitates recognition and discerns the dominant or vital genes that have been inherited by the donor. Since antigens are substances that cause the immune system within our body to produce antibodies against foreign cells, their detection is crucial in the context of stem cell transplantation. The closer the HLA match between donor and recipient is, the less likely an immune response will occur, and the better an outcome for the recipient would be.

Myths and Facts

Every new medical intervention is often laden with rumours, myths and fabled stories that are light years away from truth and facts. Decades ago, even an ordinary procedure such as blood donation had its share of folklore, mostly a cultivation of an imaginative fantasy originating from the doubting minds. The concept of stem cell transplantation is no exception to this stigma.

The concept of blood stem cell transplantation has a lot of myths and rumors surrounding it which may serve as a deterrent to those who wish to commit to be a donor, making the procedure extremely complicated. Here, in this section we have busted most of these myths.  Time to learn the FACTS!

Myth: Stem cell donation entails surgery

Fact: It’s an outpatient non-surgical mechanism done through a process called Apheresis. This is a very similar process to donating blood and is very minimally invasive.

Myth: Donated cells may never be restored.

Fact: Human body rehabilitates the donated stem cells within four to six weeks. Donors are back to into their normal groove in a few days. It’s a pretty easy procedure and doesn’t harm the donor in any way!

Myth: A transplant involves a long drawn-out and lengthy recuperation.

Fact:  Peripheral stem cell donors are reported to have differing mild symptoms like nausea, headache, muscle or bone pain, insomnia and fatigue that generally subside soon after donating.

Myth: A huge family is equivalent to finding a suitable match within the parentage and bloodline

Fact: The criterion and requirements of being a match are so diverse that the probability of discovering one within the family or sibling is at best 25%.

Learn about your disease

If you or someone you know is diagnosed with a serious blood disorder like blood cancer (Leukemia or Lymphoma), Thalassemia or Aplastic Anemia, a blood stem cell transplant may be the best or only hope for a cure. While we are neither a hospital nor a treatment center, we can provide you with support and information you need to learn about blood disorders, treatment options and transplant support.

Some of the more common blood disorders treated with a blood stem cell transplant are listed below:

  • Acute Lymphoblastic Leukemia (ALL)
  • Acute Myelogenous Leukemia (AML)
  • Adrenoleukodystrophy (ALD)
  • Chronic Lymphocytic Leukemia (CLL)
  • Chronic Myelogenous Leukemia (CML)
  • Hodgkin’s Lymphoma
  • Hurler Syndrome
  • Krabbe Disease (Globoid-Cell Leukodystrophy)
  • Metachromatic Leukodystrophy (MLD)
  • Multiple Myeloma
  • Myelodysplastic Syndromes (MDS)
  • Non-Hodgkin’s Lymphoma (NHL)
  • Severe Aplastic Anemia
  • Severe Combined Immunodeficiency (SCID)
  • Sickle Cell Disease (SCD)
  • Wiskott-Aldrich Syndrome (WAS)