What is "immunosuppression"

n. (context immunology medicine English) The active medical suppression of the immune response.

n. lowering the body's normal immune response to invasion by foreign substances; can be deliberate (as in lowering the immune response to prevent rejection of a transplanted organ) or incidental (as a side effect of radiotherapy or chemotherapy for cancer)

Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse reaction to treatment of other conditions.

In general, deliberately induced immunosuppression is performed to prevent the body from rejecting an organ transplant, treating graft-versus-host disease after a bone marrow transplant, or for the treatment of auto-immune diseases such as systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome, or Crohn's disease. This is typically done using medications, but may involve surgery ( spleen removal), plasmapharesis, or radiation.

A person who is undergoing immunosuppression, or whose immune system is weak for other reasons (for example, chemotherapy or HIV), is said to be immunocompromised. An immunosuppressant is any agent that weakens the immune system, including immunosuppressive drugs and some environmental toxins.