What Is A Stem Cell Transplant?

Stem cells are produced in the bone marrow of the human body. They can become any cell the body requires. When mature, stem cells become RBCs, WBCs, or blood platelets.

Stem Cell replacement is when a patient receives healthy blood cells to replace the damaged stem cells caused by strong chemoradiation while undergoing cancer treatment. It is also done to replace the affected stem cells due to naturally occurring diseases. Anaemia and bleeding are the most common symptoms of damaged Stem cells in the human body.

Before a stem cell replacement, the patient is required to undergo strong chemoradiation to prepare for the transplant. This process of conditioning the body to accept new stem cells from a donor is called 'Conditioning treatment'. After a Stem Cell Transplant, the donor cells move to the recipient's bone marrow to form new healthy blood cells. This process is called 'Engraftment'.

Stem cell replacements can be broadly classified into six kinds. They are:

Autologous Stem Cell Transplant
Allogeneic Stem Cell Transplant
Hematopoietic Stem Cell Transplant
Peripheral blood Stem Cell Transplant
Bone marrow Stem Cell Transplant and
Cord Stem Cell Transplant

While Autologous and Allogeneic transplantations are the most common forms of Stem Cell Transplants, sometimes, depending on the nature of the condition, patients are advised Reduced Intensity Stem Cell Transplants and Syngeneic transplantation, too.

Why Is A Stem Cell Transplant Done?

Stem cell replacement is a part of the bone marrow transplant. After conditioning treatment or radiation therapy, it replaces the affected stem cells to improve the bone marrow's efficiency in producing new blood cells.

After radiation therapy or conditioning, the body is exposed to large volumes of anti-carcinogenic elements that kill cancerous cells. In this process, the bone marrow is also affected and loses its capability to produce new blood cells. The body's immune system is weak at this point as no white blood cells or stem cells are made. With a stem cell transplant, the host (patient) is induced with healthy stem cells that move to the bone marrow, form new blood cells, and strengthen the immune system to fight the remnant cancer cells weakened after radiation.

Types Of Stem Cell Transplants:

Autologous Stem Cell Transplant

Autologous Stem Cell Transplant is a procedure that uses the patient's blood cells to produce new stem cells. In this process, the patient undergoes 'Cell mobilisation', which encourages the body to produce more stem cells and initiates the movement from the bone marrow to the bloodstream. Stem-cell-rich blood is then collected from the patient and processed into a machine that separates the stem cells from the blood. Then, it is stored in sub-zero conditions for later usage.

The rest of the blood is sent back to the patient's body, after which the chemotherapy treatment begins. Chemotherapy's strong radiation regimen kills all cancerous cells, but it also destroys the blood-producing cells in the bone marrow.

The significant advantage of Autologous Stem Cell Transplant is that it does not expose the patient to any risks regarding graft vs. host adoption.

Allogeneic Stem Cell Transplantation

In Allogeneic Stem Cell Transplants, the patient receives stem cells from a donor and is executed after conditioning treatment or chemotherapy. In this process, the stem cell-rich blood of a matching donor is processed in a machine that separates stem cells from the blood and is transferred into the host's body.

After conditioning treatment and chemotherapy, the blood-making cells are severely damaged, and hence, the immune system tends to be weak.

The new stem cells from the donor are induced into the body for engraftment. In this process, the new stem cells travel to the bone marrow and form new blood cells.

In allogeneic Stem Cell Transplants, the host's immune system strengthens as the new stem cells form a new immune system. The new blood cells formed also tend to be very effective in removing the remaining cancerous cells in the body. It is called the graft versus tumour effect.

Allogeneic Stem Cell Transplants succeed when the HLA (Human Leukocyte Antigens) found in the white blood cells match. Donors are tested for compatibility with a series of HLA tests.

Most matches in HLAs are from:

HLA-matched unrelated donor
HLA miss-matched family member
Unrelated umbilical cord blood
HLA-matched relative (most often a sibling)

Hematopoietic Stem Cell Transplant:

Hematopoietic Stem Cell Transplant is an intravenous cell replacement process that induces stem cells to replace the damaged cells affected by radiation treatment.

Hematopoietic Stem Cell Transplant has been widely used since the early 1960s and has been prominent in treating and curing carcinogenic and autoimmune diseases. Multiple Sclerosis is often treated with this method.

Peripheral blood stem transplant:

Peripheral blood stem transplant is a hematopoietic Stem transplant (HSCT) form used in Autologous and Allogeneic Stem Cell Transplants. In this process, the stem cells are collected from the blood rather than the source, i.e. the bone marrow. This process is less invasive and can be conducted from authorised Peripheral blood stem cell (PBSC) centres. The same blood found in the bone marrow is found in the bloodstream. This process is chosen depending on the type of the disease, the stage of severity, age, and other conditions of the patient.

Bone marrow transplant:

Bone marrow transplant is a procedure that replaces the cells that are produced by the bone marrow. Bone marrow is a soft tissue present inside the bones as a soft tissue. The bone marrow produces stem cells, which become red blood cells, white blood cells, and blood platelets, or new stem cells are formed if required. Certain cancerous and non-cancerous diseases affect the bone marrow; hence, the produced stem cells are also affected. In a bone marrow transplant, the cells are either replaced through an invasive procedure from the bone marrow or a non-invasive intravenous procedure through the veins. Invasive bone marrow tissue transplants are only recommended when the disease is a potential threat and if the patient's physical conditions and age support it.

Cord blood Stem Cell Transplant:

Cord blood Stem Cell Transplant is a process witnessing increased adoption worldwide. Like the peripheral blood and bone marrow, the umbilical cord is also a rich source of stem cells. Cord blood Stem Cell Transplants are most effective in treating children and have seen efficient results in the case of adults.

With a cord blood Stem Cell Transplant, the patient's chances of experiencing graft vs. host disorder are significantly reduced. Additionally, Cord blood Stem Cell Transplants are the least risky in terms of disease transmission compared to the other types of Stem Cell Transplants.

Preserving Cord blood stem cells is also easier, as they have a longer shelf life. Though a definitive figure on its shelf life has not been released, there are cases where cord stem cells from 10 years ago were used successfully.

Diseases And Conditions That Require Stem Cell Transplantation

Multiple Myeloma:

Multiple Myeloma is a condition that requires a Stem Cell Transplant as a viable treatment option. It affects the plasma of white blood cells, which generate antibodies that identify and attack foreign bodies. In multiple Myeloma, affected plasma cells tend to overcrowd the bone marrow, the cell-generating factory, and cause complications. Cancer-infected plasma cells, instead of producing healthy antibodies, produce abnormal cells.

Leukaemia:

Leukaemia is caused when specific cancerous cells attack white blood cells. White blood cells are essential for fighting foreign objects and disease-causing agents. Normally, white blood cells divide and grow according to the body's requirements. However, when infected with Leukemia, White blood cells function abnormally, which can cause several severe complications. After conditioning treatment or radiation therapy, a Stem Cell Transplant can help the body build a new immune system that can also fight off the remaining weakened cancer cells.

Non-Hodgkin lymphoma:

Non-Hodgkin Lymphoma is a cancer originating in the Lymphatic cells and spreading throughout various body parts. This effect is intensified as the lymph nodes are the body's network for fighting diseases and are spread across the body. Non-Hodgkin's lymphoma occurs when lymphocytes portray an irregular cell regeneration cycle. Normally, lymphocytes are created; they grow and divide and eventually perish, thus making room for new cells to be created. In patients with this condition, the birth rate and mortality rate of Lymphocytes are not constant; the older and weaker lymphocytes do not perish and tend to overcrowd the lymph nodes.

Hodgkin lymphoma:

Hodgkin Lymphoma is a disease that is either passed on through genetic mutation or is caused by Epstein-Barr-Virus. The prime age for a patient to be affected by Hodgkin Lymphoma is either when they are between 15-30 years or after 55. Chemotherapy and radiation therapy are effective ways to cure or treat Hodgkin's Lymphoma, depending on the severity of the condition. A Stem Cell Transplant provides the body with a fresh set of cells to equip the body to fight off the weakened cells and create a new immune system.

Myelodysplastic syndrome (MDS):

Myelodysplastic Syndrome (MDS) occurs when blood cells are not fully matured and are not released from the bone marrow. While there are no early-stage symptoms, the progression of MDS can cause shortness of breath, make the body susceptible to various infections, and eventually lead to leukaemia.

A Stem Cell Transplant can slow the progression of MDS to leukaemia and, when treated in the early stages, can be an effective cure.

Myelofibrosis:

Myelofibrosis is an uncommon form of cancer that causes scarring in the bone marrow. It leads to severe anaemia, loss of blood platelet count, excessive bleeding and other complications. Myelofibrosis and its severity depend on a case-to-case basis. There have been instances where Myelofibrosis, when left untreated, did not pose any immediate or probable future threat. In some cases, strong chemoradiation therapy is used either as an option for treatment or a cure.

A Stem Cell Transplant is an effective way to create a new immune system and regenerate the immune system.

Aplastic Anemia:

Aplastic Anemia is a condition in which the body does not produce enough RBCs(oxygen-carrying cells), WBCs (antibodies), and blood platelets(healing cells). Pregnancy, autoimmune diseases, the use of certain drugs, exposure to toxic chemicals, and radiation treatments generally cause aplastic anaemia.

A Stem Cell Transplant embellishes the bone marrow with new stem cells that graft with the body to become new RBCs, WBCs, Blood platelets, or new stem cells.

Autoimmune diseases:

Autoimmune is a condition in which the antibodies start attacking the soft cell tissues of the body instead of disease-causing agents. It is a genetic disorder, and treatment options are suggested based on the severity of the condition. In most cases, reducing the strength of the immune system is recommended.

Risks Associated With Stem Cell Transplants

Knowing the risks associated with Stem Cell Transplants is important, as this information helps treating doctors and patients make informed decisions about treatment options.

Significant risks associated with Stem Cell Transplants include:

Graft Vs Host Syndrome
Scaly skin, itching, and Rash
Nausea, Vomiting, and abdominal cramps
Jaundice
Dry mouth, damaged lungs, oesophagus and other organs
Loss of appetite
Weight loss
Infections
Cataract and
Infertility

The Stem Cell Transplant Procedure

A stem Cell Transplant is risky, and only some patients are advised to undergo it due to factors including the patient's prior medical history, their ability to withstand the radiation treatment, and its side effects. For some patients, a reduced intensity of allogeneic treatment is advised.

Salient factors that are considered before a patient is administered Stem cell replacement are:

The patient's general health conditions
Previous medical history
The severity of the condition
The probability of the body responding to the treatment
Availability of stem cells either from self or a donor

Stem Cell Transplant is strenuous on the body; hence, the patient is advised to discuss options for medical tests, fertility, intravenous catheter insertion, costs involved, and caregiver.

1. Medical tests: Before a Stem Cell Transplant is chosen, the patient is asked to undergo a series of medical tests to understand the body's condition and predict the outcome of such a procedure.

2. Fertility: In a Stem Cell Transplant, the patient is exposed to harmful amounts of radiation, and this can affect the fertility of the patient. If the patient is of a birth-giving age or is considering giving birth shortly, then options on storing eggs or sperm should be discussed with a physician.

3. Intravenous catheter insertions: Inserting a central line in the body is essential as the patient will be undergoing many blood transfusions, injections, chemotherapy, and other fluids, which can be painful if done without a central line.

4. Cost involved: A stem cell replacement transplant is an expensive procedure. When this procedure is considered a treatment option, the patient should disclose their financials with the medical team. Most insurance policies cover most of the expenses incurred. However, it is always advisable to talk to the insurance companies to understand every minor detail involved to ensure that no new major expenses are uncovered during stem cell replacement.

Stem Cell Transplant Criteria And Requirements

The best way to know if you or a family member is eligible for a Stem Cell Transplant is to contact your doctor or the hospitals that support Stem Cell Transplants.

The tests involved in deciding the eligibility criteria include:

Psychological evaluation
Blood tests
Bone marrow tests
Chest X-rays and CT scans
Heart, lung, and other organs function check

Finding A Donor

Finding a donor for a stem cell replacement is a long and often arduous process, as a good match happens in only 3 out of 10 cases in unrelated donors and 5 out of 10 cases in related donors.

The patient undergoing the Stem Cell Transplant will be the priority as the stem cells from their body are unlikely to be rejected by the body in GVHS after the transplant. However, the medical team will test to see if you are an excellent donor based on your weight, general conditions, severity, and the rate at which the existing stem cells are affected.

Siblings are generally considered the next best option when looking for an HLA-matched donor. Due to the genetic composition of the HLA from their biological parents, siblings have a higher chance of being a good HLA match for an allogeneic Stem Cell Transplant.

When siblings are not an HLA match, the search for a donor begins, and the existing cells in the storage facility are combed through to find stem cells or umbilical cords that match the patient's HLA. Furthermore, volunteers who sign up for Stem Cell Transplants are also contacted to see if they are a potential match for the procedure.

Road To Recovery And Aftercare

The road to recovery after a stem cell replacement transplant is exhaustive and intensive, as the patient's immune system becomes similar to that of a newborn baby. The medical team coaches the caregiver and patient on how to navigate this transition, and any concerns or queries are addressed before the patient is discharged from the hospital.

1. Medical Alert Jewelry:

Before leaving the hospital, patients have a bracelet or necklace engraved with 'Autologous Stem Cell Transplant' or 'Irradiated cellular blood components and CMV-safe blood components only'. This is handy when you are being examined/treated by medical experts who cannot provide information on your recent transplant. It helps the medical team treating you consider your history and administer practical medical judgment.

2. Psychological balance:

After a prolonged stay at the hospital, going back home and being surrounded by your loved ones can indeed be something to look forward to. But, after multiple rounds of chemotherapy and blood transfusions, going back home and feeling the same about it can be slightly challenging.

However, with time, patients tend to adjust to their old surroundings, and things that stress them do not have the same effect.

3. Pets:

Animals carry a variety of diseases, and it is not advisable to be around pets or animals for at least 12 months after treatment as the immune system is very weak. The chances of catching an infection are very high.

4. Home environment:

Always drink and eat from neatly washed utensils. Wear clean clothes that have been properly dried under the sun. When at home, avoid touching soil or plants, and when done, ensure that gloves and masks are used.

Do not use a humidifier at home. It creates a musty environment, a perfect breeding ground for bacteria.

5. Friends and family visitation:

There are no restrictions on who you meet. However, it is advisable to meet people in small groups.

Active efforts should be made to ensure that people with these conditions do not have direct contact with the patient:

Anybody who has a cold
Anybody who has chickenpox
Anybody who has been recently exposed to chickenpox
Anybody who has been recently exposed to Herpes virus
Anybody who has been exposed to shingles or other forms of infections
Anybody who has received a live virus vaccination

6. Sexual Health:

It is advisable to consult your doctor before resuming your sexual life. It is strongly advised not to involve in oral, vaginal, and anal sex if the platelet count is under 50,000 units.

Use latex condoms if you are participating in oral, vaginal, or anal sex. If you are allergic to latex, contact your medical practitioner for alternatives.
Use condoms or dental dams to prevent the discharges from entering your mouth during oral sex
Use condoms so that you don't get pregnant. If you are considering getting pregnant, it is recommended to contact your medical practitioner to be aware of the recovery stage you are in and the possibilities of complications, if any.

7. For women:

After a Stem Cell Transplant, you may have fewer or no menstrual periods, along with itching and dryness in the vaginal region.

Using skin products that reduce dryness in vaginal regions is advisable. There are creams available with zero hormones that can be obtained without a prescription either online or at a local pharmacy.

8. For men:

After a Stem Cell Transplant, you could experience erectile dysfunction, and this might affect your personal life. However, this is temporary and can be improved with regular exercise.

This condition can also be treated with medications like Viagra.

9. Consumption of Alcohol and Tobacco:

Consumption of tobacco or any tobacco-based products like cigarettes, cigars or marijuana is strictly prohibited after undergoing a stem cell replacement transplant.

Consumption of alcohol is also prohibited as it may damage the kidneys, and the effect could multiply at a faster rate than usual due to a suppressed immune system.

It is advised to consult a doctor to talk about when it is safe for alcohol consumption after the transplant.

10. Eye-care:

After a stem cell replacement transplant, the patient may develop a cataract, and hence, it is advised to visit an ENT specialist.

It is advised to consult a doctor if:

The vision is blurry or foggy
If you witness any change when viewing colours
If you have problems driving at night
If you are experiencing double vision