Maisonneuve-Rosemont Hospital Université de Montréal

Infectious diseases

Infections: An omnipresent risk

One thing that all the treatments used to prepare patients for a transplant—whether chemotherapy, radiotherapy or immunosuppression—share is that they can cause an immune deficiency. This means that patients’ bodies do not have the capacity necessary for defending against external attack.

When an autologous or myeloablative allogeneic transplant is performed, the intensive chemotherapy and/or radiotherapy involved causes a period of bone marrow aplasia. During this time, the body can no longer make white blood cells, the pillars of the immune system that are responsible for defending the body against invading organisms. Without this defence system, patients become vulnerable to infections.

In the case of non-myeloablative transplants, patients do not undergo a prolonged period of aplasia. Nevertheless, the immunosuppressive treatment that they do receive prior to the transplant blocks the action of the white blood cells against attack.

Such attacks may come from:

Most patients have to take antibiotics as a precaution in order to avoid contracting diseases that could complicate the rest of the treatment. During the most acute stage of the immune deficiency, that is, over the course of the transplant-preparation treatment and until the restoration of bone marrow function (either because the transplant has taken and/or there is a return to an appropriate blood count), patients will be kept in isolation in a sanitized environment or under strict medical supervision (often for the first 30 days).