The effects of immunosuppressive drugs on human immunocompetence.

Immunosuppressive drugs are agents capable of suppressing the development of at least one type of immune response in vivo at doses with minimal side-effects. After an introduction in which different types of immune responses are briefly discussed, some characteristics regarding the mechanism of action of prednisolone, azathioprine, cyclophosphamide and anti-lymphocyte serum (ALS) will be reviewed. Corticosteroids display mainly an anti-inflammatory effect. The immunosuppressive effect of azathioprine is questionable, cyclophosphamide influences the immune system itself and ALS suppresses fairly specific cellular immunity.