Peripheral Blood Stem Cell Transplant (PBSCT) or Bone Marrow Transplant

A Peripheral Blood Stem Cell Transplant (PBSCT) or Bone Marrow Transplant is a way of transplanting a new immune system into a person’s body. The immune system consists of stem cells that make all the different kinds of blood cells that perform the functions of the immune system, these are -:

• Red blood cells – these carry oxygen around the body
• White blood cells – these cells travel around the body destroying bacteria, viruses and abnormal cells in the body such as cancer cells
• Platelets – these cells help the blood to clot

A transplant involves destroying the persons own immune system and stem cells and replacing them with either -:

• Their own previously harvested stock of stem cells or bone marrow – this is called an autologous transplant because a person’s own cells are used.
• Someone else’s stem cells or bone marrow – this is called an allogeneic transplant because someone else’s cells are used.

The donor usually has the same or similar genetic markers to the recipient. Checking for compatibility between donor and recipient is called ‘matching’. The other person can be a close relative such as a brother or sister – a ‘sibling donor’ or someone who is unrelated – this is called a ‘matched unrelated donor’. The name of the procedure depends on how the stem cells are collected from the donor although the principles of the procedures are the same and the effect on the recipient is the same:

Peripheral Blood Stem Cell Transplant (PBSCT)

Peripheral blood stem cells are harvested from the blood. Growth factors are given to the donor to promote production of larger quantities than normal of stem cells for harvesting. These spill out into the peripheral blood from the bone marrow. The stem cells are filtered from the blood using a procedure similar to blood donation. No anaesthetic is required and the process takes several hours. The side effects for the recipient are the same whether bone marrow or peripheral blood stem cells are used.

Bone Marrow Transplant

Bone marrow is harvested from bone marrow in the pelvis during a short operation. The side effects of bone marrow harvesting are minimal – for example there may be soreness around the pelvis for a week or so afterwards. The side effects for the recipient are similar whether bone marrow or peripheral blood stem cells are used.

How is a transplant given?

In preparation for transplant a person’s immune system will be wiped out by high dose chemotherapy and sometimes radiotherapy treatment. This often has the effect of killing off residual cancer cells and is the aim of the treatment. Once this treatment is complete the bone marrow or stem cells can be given via an intravenous drip. The stem cells do not start working straight away and can take up to a year to start working effectively and really protecting a person from infection.

The side effects of such high dose treatment are severe. A person is not able to produce their own red, white blood cells or platelets and the transplanted tissue is unable to do this for some time either. This means they need regular support with blood and platelet transfusions to prevent bleeding and control anaemia. Transfusions of white cells to control infection cannot be given and so despite antibiotics they are at very high risk of life threatening infection with normally innocuous bacteria or viruses. When a person is unable to produce their own white blood cells to fight infection this is called ‘neutropenia’. The high risk period after transplant when a person is very vulnerable to infection is called the ‘neutropenic period’ – the neutropenic period is usually spent in hospital.

Once some improvement has occurred and the immune system has started to work to a degree they will be discharged from hospital. The person undergoing treatment is likely to feel extremely ill and weak and may sleep for most of the time. They will have many of the side effects of chemotherapy.

Often the first phase of treatment will be given in isolation in hospital – isolation means just that, a person is kept in one room with minimal visitors who all wear barrier clothing to prevent the transfer of infection. The psychological effects of isolation can be severe. The time spent in isolation in the recent past was 1-2 months. This time has been reduced with more of the recovery time spent at home. The same precautions may be necessary at home as would be taken in an isolation room in hospital. These may be troublesome for carers in terms of cleanliness of the home, providing safe food, preventing contact with potentially harmful everyday items and restricting access to people who are themselves unwell. In addition frequent blood tests are needed to monitor progress and this is likely to involve accompanying their family member to hospital and back.