Bone Marrow Transplantation - Understanding the Risks and Complications

Introduction

A bone marrow transplant is the process by which healthier bone marrow cells replace the older ones. It is also called a hematopoietic stem cell transplant or a stem cell transplant. These transplants aid in the effective treatment of various types of cancer. On the other hand, they can cause severe complications and rarely life-threatening situations based on the type of transplant, immunity, and other factors that differ from one person to another. Managing these complications is an integral part of cancer treatment, known as palliative or supportive care.

What Is a Bone Marrow Transplant?

Stem cells are the unique cells of the body that can be replicated into various kinds of cells based on the body's requirements. For example, hematopoietic stem cells are stem cells that turn into blood cells. Hematopoietic cell defects reduce the production of red blood cells, platelets, and white blood cells. On the other hand, bone marrow is a soft, spongy tissue found primarily in the center of the bones that contains hematopoietic stem cells. A bone marrow transplant is the procedure by which healthier bone marrow cells replace the older bone marrow cells or hematopoietic cells, to regulate the action of red blood cells, platelets, and white blood cells.

What Are the Types of Bone Marrow Transplants?

The bone marrow transplant is distinguished into two major categories:

• Autologous Transplant: An autologous transplant takes the stem cells of the same individual. Usually, stem cells are extracted from blood or bone marrow before chemotherapy or radiation (cancer treatment) to prevent its side effects and alter the immune system. Later, it is replaced within the bone marrow to produce blood cells and fight against the infection. This procedure is also known as a stem cell rescue or an autotransplant.

• Allogeneic Transplant: An allogeneic transplant takes the stem cells of another individual, called the donor. Like autotransplant, the donor's stem cells are retransplanted to them after chemo or radiation therapy on affected individuals. This procedure is also known as an allotransplant.

What Are the Side Effects of Bone Marrow Transplantation?

The side effects of bone marrow transplantation vary depending on the type of transplant, the underlying disease, the characteristics of the donor, and other medical conditions. The most common side effects are:

• Nausea.

• Vomiting.

• Diarrhea.

• Soreness in the mouth or throat.

• Respiratory distress.

• Infection.

• Organ failure.

• Graft failure.

• Jaundice.

• Liver dysfunction.

What Are the Complications of Autotransplantation?

The significant side effects of autotransplantation are similar to those of chemotherapy and radiation, with an increased risk of infection and decreased levels of white blood cells. The most common side effects of autotransplantation are:

• Nausea, Vomiting, and Diarrhea: Gastrointestinal tract irritation results in nausea and vomiting. Antiemetic drugs (medicine for vomiting) and intravenous fluids often manage these conditions. The frequent loss of fluid and dehydration give rise to diarrhea.

• Mouth Sores: Soreness and pain in the mouth and throat are common in chemotherapy and radiation patients. In an attempt to target cancer cells, regular mouth and throat cells are temporarily disrupted, resulting in mucositis (inflammation of the mouth or gut). Mucositis causes pain, soreness, and burning sensations in the mouth and throat, making it difficult to eat. The management of mucositis involves using mouthwash to maintain an antiseptic condition and prevent infection. Then, the essential nutrients are injected through an intravenous line. Treatment for viral and fungal infections began with morphine for symptom relief.

• Infection: Chemotherapy, radiation, and a bone marrow or stem cell transplant decrease white blood cells, which aid in protecting the body against disease. Overall, they shatter the immunity, and it takes two weeks to recover the immune cells and immunity. As a result, there is a greater risk of bacterial, viral, and fungal infections. Hence, antibiotics are prescribed to avoid these infections.

• Low Platelet and Red Blood Cell Count: The decrease in platelets and red blood cells can lead to thrombocytopenia (bleeding in the internal parts of the body) and anemia (a decreased hemoglobin can give rise to fatigue, a lack of appetite, and increased heart rate).

• Hair Loss.

• Weight Loss.

What Are the Complications of Allotransplantation?

Allogeneic transplantation uses donor stem cells, raising the risk of infection and complications.

• Graft-Versus-Host Disease (GVHD): A potentially fatal condition in which donor cells attack and destroy the recipient's body, mistaking it for a foreign object. GVHD is an acute or chronic condition characterized by a skin rash, diarrhea, nausea, and abdominal pain. It is diagnosed by liver function tests, and medications like steroids and cyclosporine are used to reduce the risk of this complication.

1. Acute GVHD: It often affects the skin, intestines, and liver with the symptoms of rashes, diarrhea, and jaundice. It can occur within the first three months after an allotransplant.

2. Chronic GVHD: It develops after three months of allotransplant and lasts for a few months to life long. The chronic condition is with or without symptoms of liver irritation, joint and muscle pain, scleroderma (an autoimmune disorder of connective tissue, which is characterized by thickening and hardening of the skin), infection, and shortness of breath.

• Pneumonitis: The inflammation of lung tissue and interstitial spaces caused by chemotherapy, radiation, and graft-versus-host disease. It is diagnosed with chest X-rays and is characterized by breathing difficulties. The majority of cases occur within the first 100 days of transplantation. Immediate medical attention is needed for this condition.

• Veno-Occlusive Disease (VOD): A partial or complete obstruction of liver blood flow results in jaundice, liver dysfunction, weight gain, and abdominal swelling. It occurs within about three weeks after the transplant. The severe form of VOD is a life-threatening condition, so early diagnosis is essential.

• Graft Failure: Rarely does the body not accept the new stem cells (graft) due to infection, recurrent disease, and insufficient graft. This potential complication is called graft failure. It is treated with a second dose of stem cells. Luckily it is not a life-threatening condition.

Conclusion

A bone marrow transplant is a medical procedure that uses healthy bone marrow stem cells to replace your bone marrow. It is also known as a hematopoietic stem cell transplant or a stem cell transplant in general. Certain cancers and other conditions that affect the bone marrow can be treated with this kind of transplantation. It may have side effects, just like any other cancer treatment. Depending on the type of transplant patients receive, general health, and other parameters, these side effects can vary from person to person. The higher range of chemotherapy before transplant gives rise to long-term physical effects like organ damage, abnormal thyroid function, infertility, early menopause, and eye cataract. The complications of bone marrow transplant are unavoidable, although early diagnosis and management increase the survival rate.