These are agents, principally drugs, that adjust the activity of a patient’s immune response, either up or down, until a desired level of immunity is reached. The principal targets of im-mune modulation are the specific components of the immune response, T and B-lympho-cyte clones, which can hopefully be selectively “fine-tuned” in their function to promote the better health of the patient. Three general clinical scenarios dominate the immunomod-ulation landscape:
1. Immunosuppressive therapies, utilized when specific T and B lymphocytes of the patient’s immune system have become activated against the patient’s own body organs, such as in autoimmune diseases or in organ transplantation
2. Induction of hyporesponsiveness or tolerance, which has the advantage of tar-geting the undesirable immune response rather than inducing a generalized im-munosuppression. In some cases, the effect of hyposensitization is truly im-munomodulatory, shifting the response from pathogenic to protective or indifferent, as in the case of hyposensitization of patients with IgE-mediated hypersensitivity .
3. A third modulator option is to attempt to boost the overall B- and T-lympho-cyte function of the patient (Immunopotentiation). This can be accomplished either by actively stimulating the patient’s own immune system to higher performance levels through immunization techniques or by passively introduc-ing protective immune system components from outside sources, such as gamma globulin or hematopoietic growth factors, into the pa-tient’s body.
The effects of these drugs do not focus upon the function of T and B lymphocytes but are rather directed toward changing the function of the nonspecific inflammatory components of the immune system, mononuclear phagocytes, polymorphonuclear granulocytes, natural killer (NK) cells, and mast cells. These cells play an essential role in the elimination of in-fectious agents and are also the key to inflammatory processes as-sociated with anti-infectious responses, autoimmunity, or hypersensitivity, which can have devastating effects for the patient.