Encyclopedia of Health and Medicine

276 The Immune System and Allergies
with the goal being to block the body’s rejection of
a transplanted organ or bone marrow and to prevent
GRAFT VS. HOST DISEASE. Common immunosuppressive
medications include
• CORTICOSTEROID MEDICATIONS, which inhibit the
production of eosinophils, suppress the COMPLE-
MENT CASCADE, and block the activation of antibodies
• DISEASE-MODIFYING ANTIRHEUMATIC DRUGS
(DMARDS), which block the immune response in
such of a way as to alter, at least temporarily,
the course of the disease
• cytotoxic agents, which kill cells (cells that
replicate rapidly, such as BLOOD cells, are more
greatly affected)
Doctors prescribe immunosuppressive medications
to treat AUTOIMMUNE DISORDERS, HYPERSENSITIV-
ITY REACTION, and to prevent an immune response
that targets a transplanted organ. Often doctors
prescribe these medications in combination to
quell the immune response on several fronts. This
allows lower dosages for each type of medication,
reducing the overall amount of medication the
person must take and minimizing side effects. The
approach also provides greater relief in severe presentations
of chronic inflammatory diseases such
as RHEUMATOID ARTHRITIS and SYSTEMIC LUPUS ERYTHE-
MATOSUS (SLE).
Immunosuppressive medications have numerous
side effects, DRUG interactions, and risks specific
to the medication. In general, the primary
risk of immunosuppressive medications is INFEC-
TION, particularly OPPORTUNISTIC INFECTION. Though
doctors try to maintain a balance of immune suppression
that controls symptoms yet allows the
body to protect itself from infection, IMMUNOSUP-
PRESSIVE THERAPY opens the gateway for pathogens
to invade. Aggressive antibiotic therapy then
becomes necessary to eradicate the infection.
See also ANTIBIOTIC MEDICATIONS; ANTIHISTAMINE
MEDICATIONS; CHEMOTHERAPY; DRUG INTERACTION; LIV-
ING WITH IMMUNE DISORDERS; ORGAN TRANSPLANTATION;
PATHOGEN.
immunosuppressive therapy Treatments that
limit or suppress the IMMUNE RESPONSE. Such treatment
may incorporate IMMUNOSUPPRESSIVE MEDICA-
TIONS such as CORTICOSTEROID MEDICATIONS, DISEASE-
MODIFYING ANTI-RHEUMATIC DRUGS (DMARDS),
CHEMOTHERAPY, RADIATION THERAPY, and MONOCLONAL
ANTIBODIES (MABS).
Doctors may prescribe short-term immunosuppressive
therapy (two to six weeks) to treat moderate
to severe type I HYPERSENSITIVITY REACTION or
to reduce INFLAMMATION due to injury. Long-term
immunosuppressive therapy is generally a treatment
option for chronic AUTOIMMUNE DISORDERS
such as SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) and
RHEUMATOID ARTHRITIS. People who have had organ
transplants must take lifelong immunosuppressive
therapy to reduce the risk for organ rejection and
GRAFT VS. HOST DISEASE. The risk for complications
and side effects rises the longer a person is on
immunosuppressive therapy.
Immunoablation (the administration of high-
DOSE chemotherapy or radiation therapy) wipes
out the immune response altogether by killing the
BONE MARROW, which removes all leukocytes and
their subtypes from the IMMUNE SYSTEM’s resource
arsenal. This form of immunosuppressive therapy
prepares the body to receive BONE MARROW TRANS-
PLANTATION or STEM CELL transplantation, which
then rebuilds the immune system from the marrow
up.
See also COMPLEMENT CASCADE; LEUKOCYTE; LIVING
WITH IMMUNE DISORDERS; ORGAN TRANSPLANTATION;
PROSTAGLANDINS.
immunotherapy The therapeutic use of biologic
agents to manipulate the mechanisms of the
IMMUNE SYSTEM. Immunotherapy, also called biologic
response modification, is an effective method
for reducing INFLAMMATION and other aspects of the
IMMUNE RESPONSE to treat inflammatory AUTOIM-
MUNE DISORDERS such as RHEUMATOID ARTHRITIS.
Immunotherapy is also a treatment option for
many forms of cancer. The common types of
immunotherapy are
• CYTOKINES such as INTERLEUKINS and INTERFERONS,
which boost the cytotoxic (cell-killing) actions
of T-cell lymphocytes and natural killer (NK)
cells
• COLONY-STIMULATING FACTORS (CSFS), which stimulate
the growth of leukocytes and lymphocytes
(white BLOOD cells) in the BONE MARROW