Pediatric Hematopoietic Stem Cell Transplant

Hematopoietic stem cell transplant is a recent innovation that came to be during the last few decades. It’s an increasingly effective alternative of curing an array of both malignant and benign disorders among children. 

A pediatric hematopoietic stem cell transplant can also be referred to as a bone marrow transplant. It’s generally a treatment to replace the damaged or lost bone marrow with healthy stem cells. Initially, the transplant procedure was used to address cancers and various blood diseases. But today, it is progressively being applied in the treatment of a range of developing conditions. This includes genetic immunodeficiencies, bone marrow failure, and metabolic disorders, among others. 

What are the Stem Cells or Bone Marrow?

Stem cells are specialized cells that can replicate themselves. They can also develop into the multiple forms of cells that the body requires. Numerous types of stem cells exist, and they can be located in various areas of the body at varying periods. Malignant conditions and the associated treatment or therapy can harm the hematopoietic stem cells. These cells give rise to significant blood cells.

The bone marrow is an elastic and spongy tissue distributed in the body that consists of hematopoietic stem cells. It’s located in the middle of the majority of bones. The hematopoietic stem cells are also present in the blood that circulates through the body. 

If hematopoietic stem cells are destroyed or altered, they can fail to develop into white blood cells, red blood cells, and platelets. These blood cells are essential, and each one serves a specific purpose in the body. 

Red blood cells are responsible for transporting oxygen in the body. Moreover, they transport carbon dioxide to the lungs, where it is exhaled. White blood cells form part of the body's immune system. They combat pathogens, which include bacteria and viruses that can cause illness. On the other hand, platelets play the role of stopping bleeding by forming clots. 

Types of Pediatric Hematopoietic Stem Cell Transplant 

The major types of hematopoietic stem cell transplant in children include; 

• Autologous transplant 

The stem cells used in an autologous transplant are derived from a patient’s own body. Cancer is sometimes treated using high-dose, concentrated radiation therapy or chemotherapy. Such methods of treatment have the potential to damage the stem cells as well as your immune system. Due to this, doctors often extract or retrieve the stem cells from the bone marrow or blood before carrying out the treatment. 

Following chemotherapy or radiation therapy treatment, the doctor restores the stem cells into the body. This reestablishes the immune system and the capacity of the body to create blood cells and combat any infection. 

• Allogeneic transplant 

The stem cells used for an allogeneic transplant are obtained from a different person, referred to as the donor. The patient usually receives the stem cells from the donor after undergoing chemotherapy or radiation therapy treatment. 

During the allogeneic transplant, most people experience a graft-versus-cancer cell impact. At this period, the new stem cells identify and kill any remaining cancer cells in the body. Typically, this is the key form by which allogeneic transplant functions to cure cancer. 

• Myeloablative transplant 

This type of stem cell transplant utilizes higher doses of radiation therapy or chemotherapy. It’s usually conducted before transplantation of autologous or allogeneic hematopoietic stem cells. 

• Non-myeloablative transplant

This involves the use of low doses and less intense chemotherapy before allogeneic hematopoietic stem cell transplantation. The non-myeloablative technique can be prescribed for many reasons. They can include the child’s age, the disease type, underlying medical conditions, or previous therapies.

What Happens Before Pediatric Hematopoietic Stem Cell Transplantation Process?

Hematopoietic stem cell transplantation procedures differ from one child to another. They also depend on various factors, including the type of malignancy, the child’s age, and overall wellbeing. It can sometimes vary based on the clinic's treatment schedule, the clinical trial procedure, and other considerations. 

In general, these are what often transpires before the main stem cell transplantation procedure; 

• Evaluation of the child’s health

Before the child undergoes hematopoietic stem cell transplantation, the medical provider will first evaluate the health status. The transplant team will also go through the medical history of the child. Others may be required to have several tests. 

• Placement of the central line

Before, during, and following hematopoietic stem cell transplantation, a variety of drugs may be needed. Therefore, the doctor can recommend placement of the central line before the procedure begins. This is equally significant since it helps prevent the need for several needle sticks and intravenous (IV) lines. 

Central line placement involves inserting a thin, elastic-plastic tube into a major vein located in the chest. Usually, the line is made up of two or three ports. The ports are designed to infuse drugs, blood components, and hematopoietic stem cell products and remove blood samples. 

Once the central line is in place, it’s essential to maintain the region clean and observe any infection signs. It can include pain, swelling, redness, fever, chills, or fluid discharge from the site. 

• Extracting hematopoietic stem cells

With an autologous transplant procedure, the doctor will first remove the hematopoietic stem cells from the body. This is before intensive radiation therapy, or chemotherapy begins. The main sources of hematopoietic stem cells include blood and bone marrow. 

For allogeneic bone marrow extraction, the donors will undergo the harvesting procedure a day before or on the transplantation day. During bone marrow extraction, the doctor will administer general anesthesia to avoid pain and any discomfort. 

• Transfusions of blood products 

When the bone marrow is not working normally, the child may need a transfusion of the blood products. These can include red blood cells or platelets. Usually, these blood products don’t include white blood cells since they are irradiated to minimize the possibility of an immune reaction. 

How Pediatric Hematopoietic Stem Cell Transplant Procedure is performed 

After completing the intensive chemotherapy or radiation, the doctor will prep the child for the transplantation. They will give an infusion of the collected peripheral blood or bone marrow stem cells. The infusion is administered via an intravenous (IV) line, the central line in particular. The infusion process normally takes an hour and is painless.

Once in the body system, the hematopoietic stem cells travel to the bone marrow. Here, they will reestablish natural blood cell production, a process known as engraftment. It’s crucial to find out if engraftment has developed. It helps determine if it’s safe for the child to return home or minimize isolation procedures. At times, the doctor can recommend drugs that trigger the bone marrow to create red and white blood cells. The child can use these medications daily or if engraftment tends to be much slower.

Risks and Side Effects of Pediatric Hematopoietic Stem Cell Transplant

There are various side effects associated with hematopoietic stem cell transplants in children. It’s thus essential to talk with the medical provider about the possible side effects, risks, and toxicities before your child undergoes the treatment. 

Usually, hematopoietic stem cell transplant involves body irradiation and high doses of chemotherapy. This can result in a number of adverse side effects on the child. The common side effects that can arise include; 

Nausea and vomiting: While is common in most patients, taking a combination of drugs can help prevent and cure these disorders. If you know any helpful preferences that might have assisted the child previously, share them with the transplantation team.

Hair loss: Losing hair following hematopoietic stem cell transplant is usually common but temporary. It includes loss of hair in the head, body, and face. After about two to three months of high-dose chemotherapy and radiation, hair starts to re-grow. Unfortunately, there is no medication available to stop hair loss or hasten hair re-growth.

Mouth sores (mucositis), stomach pain, and diarrhea: Radiation or chemotherapy can damage the fast multiplying cells, including skin cells within the digestive system and mouth. This causes the formation of sores in the mouth and diarrhea. If mucositis is serious and affecting the ability to feed, the doctor can prescribe intravenous nutrition (complete parenteral nutrition).In most cases, pain relievers are also administered. If the child experiences pain in the chest and abdomen, the transplant team will address them. 

Organ toxicity: The child’s bones, lungs, and kidneys are more vulnerable to damage due to stem cell transplantation procedures. Cataracts in the eyes can occur in patients who have total body irradiation. However, this problem is less frequent, especially with advanced modern ways of administering radiation therapy.

Other potential complications and side effects associated with pediatric hematopoietic stem cell transplant include; 

• Development of secondary cancers 
• Risks of infertility in the future 
• Failure of engraftment 
• Risk of death 

Conclusion 

Pediatric hematopoietic stem cell transplant is a treatment procedure that healthcare providers use to address certain types of cancers. This mostly includes blood malignancies and other chronic blood-related disorders. The transplantation procedure involves transferring healthy stem cells into the blood or the bone marrow. This helps restore the ability of the child’s body to produce the blood products it requires. 

While hematopoietic stem cell transplant may be an effective approach, it also carries various risks of complications. Therefore, as a parent, it’s essential to discuss everything about the procedure with the medical provider. Also, considering a renowned healthcare facility can contribute to successful treatment and positive outcomes.