Steroids
are natural hormones produced by the body, as well as synthetic drugs with the
same effects. One type of steroids, called corticosteroids, are very powerful
at suppressing the immune system and are often used to prevent rejection in
transplantation. These are not the same as the “anabolic steroids” abused
by cheating athletes!
Prednisolone is the main corticosteroid used
after transplantation, and suppresses all aspects of the immune system.
Although this makes it very good at preventing rejection, it also makes
patients very prone to infection and there are also a wide range of long-term
undesirable side-effects: they may cause osteoporosis (thinning of bones,
leading to fractures), diabetes and increase the risk of heart disease.
Before ciclosporin was introduced, and immunosuppression was based on azathioprine and steroids alone, doses of steroids needed to prevent rejection were much higher than used today, and so the side effects were more severe.
Because
they have such risky side-effects, transplant units are increasingly trying to
avoid or minimise use of steroids, especially in patients felt to be at low
risk of rejection. In some patients, however, long-term use of steroids will
continue to be necessary.
Methylprednisolone is a stronger version of
prednisolone which is given intravenously in high doses to treat rejection.
