Autologous stem cell transplant explained
Retired stem cell co-ordinator, Mary Farrell, explains the ins and outs of an autologous stem cell transplant.
What is an autologous stem cell transplant?
An autologous stem cell transplant is also known as high-dose chemotherapy with stem cell rescue.
The word autologous (of cells and tissues) means obtained from the same individual. Not from a donor. The cells of the individual are collected in advance and stored. Then after high-dose chemotherapy is given to treat the underlying disease, the cells are returned to ‘rescue’ the patient’s bone marrow.
What illnesses are autologous stem cell transplant used for?
An autologous stem cell transplant is an accepted procedure for illnesses which damage or destroy the bone marrow, such as multiple myeloma, Hodgkin’s lymphoma, Non-Hodgkin’s lymphoma, and some leukaemias – like acute myeloid leukaemia (AML) where the patient has done very well with initial chemotherapy.
Certain solid tumours can be treated with an autologous transplant, such as testicular cancer. I personally don’t have any experience in other solid organ transplants.
Multiple sclerosis (MS) can be treated with an autologous transplant, however, many medical aids don’t cover the cost of this.
How does an autologous transplant help the patient?
It allows the high-dose of chemotherapy to be performed without badly compromising the patient. As well as providing the patient with a better chance of cure, or long-term remission and control of their disease.
An important factor is to get the patient into remission prior to the high-dose chemotherapy and stem cell rescue. For an autologous transplant to take place, a good initial response to prior chemotherapy and remission is needed.
We need to have a healthy patient and, if possible, a break between the initial chemotherapy treatment to allow some recovery of the bone marrow to obtain stem cells.
Haematopoietic stem cells (HSCs)
The important cells that are needed are HSCs, which are produced by the patient’s bone marrow. Without those fantastic cells, a patient’s life is endangered by giving high-dose chemotherapy without ‘rescuing’ their compromised bone marrow. This is due to the compromised bone marrow not being able to produce enough suitable quantities of white cells, red cells, platelets etc. for normal life.
All humans produce stem cells, which live in our marrow and eventually become all types of blood cells. The big problem for a stem cell rescue is much larger quantities of stem cells are needed than are normally produced.
You’re probably wondering how we do this? A time table is worked out by the oncologist and transplant sister; a drug called Neupogen, a Granulocyte Colony Stimulating Factor (G-CSF), is ordered for the patient.
This is given via a subcutaneous injection (tiny little needle and prefilled syringe which is injected just under the skin into the subcutaneous fat layer) usually twice a day, in the morning and evening.
The dosage depends on the oncologist, taking into account the patient’s previous chemotherapy, and weight. It is usually given five days prior to the harvesting of the cells. I taught my patients, or their relative and friends how to do it. We had great fun practising with an empty syringe on an orange.
G-CSF side effects
Commonly bone pain and lower back ache are experienced as well as headaches and feverishness. The bone pain is due to the bone marrow (cell factory) going into overdrive.
Analgesics (pain killers) are given.
I always kept in touch with my patients during this stage to make sure all was going well, and kept everything crossed that those cells were going into the blood stream.
Harvesting the stem cells
Once the cells are in the blood stream, we harvest them. I love that expression! It just really means collecting them. If the patient has amazing veins in the crook of their elbow, a needle is inserted into each arm, and the patient is attached to the stem cell separator.
Some oncology departments may have their own machines, or else they are ordered through the Blood Transfusion Service, who would then charge the patient’s medical aid.
These machines are expensive, and need an Apheresis Sister, who is specially trained to use them. These sisters operate the machines and do the actual harvesting.
A subclavian line is used if a cancer patient doesn’t have good venous access. It’s inserted by a surgeon, under local or general anaesthesia, under X-ray into the subclavian vein just below the collar bone area, which reaches into the heart.
The line is stitched in place. It’s a two-way line that can draw blood, with the machine separating the stem cells that we need, pushing all the other cells that are not needed back into the patient e.g. red cells, platlets and white cells. (Similar to donating platelets).
The two-way line can stay in situ after harvesting for administration of chemotherapy, other fluids and treatments, blood and platelets, providing the area is healthy and comfortable.
How long does the harvesting take?
The painless procedure generally takes four hours where the patient can lie, relax or sleep. Usually, two harvests are performed on two consecutive days, and the G-CSF is timed to end the morning of the last harvesting.
The cells are counted by a Blood Transfusion Service technician, who does the cryo-preservation of the cells at main headquarters and stores them in special tanks.
They notify the transplant sister of the quantity. She then informs the oncologist. The cells are frozen slowly, and stored to be infused when the patient needs them.
The patient may feel quite tired after the harvesting. He/she will be admitted into the transplant unit to undergo high-dose chemotherapy. The chemo type and duration depends on the patient’s disease and oncologist.
This can be a trying time as some chemo protocols are quite long, with varying side effects. The patient is monitored closely in the unit as their bone marrow is been gradually ‘knocked-out’ by the chemo.
Depending on the type of chemo, there will be one rest day or several rest days to allow the chemo drugs to be flushed out. Then the patient’s frozen and thawed stem cells can be infused back into their body. Yay!
Transplant day, special day
The technician from the blood bank will bring the frozen cells and reinfuse them via the line or arm. This is a painless procedure. Usually, a patient will only need one bag of cells. The second bag will remain stored in case a repeat transplant is needed. This is often the case for multiple myeloma patients accompanied by a repeat high-dose chemotherapy. The cells are stored in special containers and tested for viruses, bacteria and cancer cells.
Once the cells are infused they will find their way to the bone marrow, where they will settle and start producing cells again. This takes time.
During the gap between the end of chemotherapy and rest day/s, the patient has no functioning marrow. Scary thought isn’t it? This is the critical time as red cells and platelets may need to be replaced as the blood counts will drop to almost zero.
White cells/lymphocytes can’t be replaced so most oncologists will re-start G-CSF injections during this time to promote re-growth of the stem cells faster.
Susceptible to infection
The patient is extremely susceptible to infection until their counts start accelerating back to normal. From transplant to a blip of an upward trend is usually at the 10-day mark but will differ from individual to individual.
The patient will be in isolation covered by antibiotics, blood and platelet infusions and on IVI fluids and supportive low-bacteria diets. This can be a lonely and worrying time for patients and some can be really ill with mouth sores and ulcers, diarrhoea, fevers and exhaustion. Mouth care is very important. Thankfully, all of these side effects are treatable.
Daily there will be blood counts, blood cultures for high temperatures, constant nursing observations, stool specimens, sputum specimens, wound dressings over line area, more G-CSF and ICU admission if needed.
It’s a busy nursing time, and observation of the patient cannot be emphasised enough. Only close family can visit. Limited. No one with any infection of any kind to visit until the patient’s neutrophil (infection fighting-cell) count is acceptable to be out of isolation.
It helps a great deal for the transplant sister to visit daily, to go through the cell counts and reassure patient and family. Once the total white cell count reaches 1.5, celebrate! The patient is on the mend after a long, tiring and trying time.
The oncologist will discharge the patient when all the cell counts are of an acceptable limit. The transplant sister will explain the medication; how to manage at home; what signs to look out for in case of re-admission. She will be at the end of the phone line and if concerned will arrange a visit, or re-admit with the oncologist’s guidance. Frequent follow-up visits are needed and if needed the patient may require further blood and platelet transfusions as an out-patient.
MEET OUR EXPERT – Mary Farrell
Mary Farrell (SRN SCM) is a retired stem cell co-ordinator. She trained at General Infirmary Leeds 1970-74, and is also a previous Hospice Sister/Chemotherapy Out-Patient Sister.