(im‵yŭ-nō-ther'ă-pē )

(i-mū‵nō-ther'ă-pē)

[ immuno- + therapy ]

The use of natural and synthetic substances to stimulate or suppress the immune response (as in patients with asthma, seasonal allergies, autoimmune illnesses, some cancers, or hypersensitivity to insect stings or anaphylaxis). Therapeutic agents are either antigen-specific or non–antigen-specific. Immunological therapies include cytokines (such as alpha interferon and interleukin-2), monoclonal antibodies, intravenous immune globulin, heat shock proteins, and cancer vaccines. SYN: immunological therapy.

adoptive i.The treatment of cancer and some chronic infections with T cells taken from patients, grown and activated in a culture where they are stimulated to react to specific tumor antigens, and then returned to patients by infusion. The adopted T cells invade the cancer and immunologically reject it. Side effects of the treatment include fever and nausea.

allergen-specific i.Specific immunotherapy.

antigen-specific i.Specific immunotherapy.

cancer i.The use of agents to alter or stimulate the immune system to recognize and attack cancer cells. Examples of cancer immunotherapies include: monoclonal antibodies, cancer vaccines, immune checkpoint inhibitors, and chimeric antigen receptor T-cell therapies, among others.

cluster i.The administration of more than one dose of allergen to a patient during a single desensitization session.

epicutaneous i.Using antigens applied to the skin via band ages or patches to desensitize people from having future allergic reactions.

nonspecific i.Induction of a general immune response with adjuvants, drugs, or vaccines that stimulate the release of interferons or other immune cytokines. Nonspecific immunotherapy differs from specific immunotherapy in that the agents used (such as BCG [bacille Calmette-Guérin] vaccine, Freund adjuvant) do not stimulate antibody production for or against individual antigens.

oral i.Administration of weakly concentrated droplets of allergens in the mouth to desensitize allergic people. It is used as immunotherapy for food allergens.

passive i.The prevention of disease by administering antibodies in the form of a gamma globulin infusion or injection. Preparations enriched with specific antibodies can be used to prevent hepatitis B (HBIG), tetanus (Hyper-Tet), and chickenpox (VZIG), and other diseases.

rush i.Immunotherapy administered rapidly, e.g., over several days (with several injections of antigen daily) or even a single day.

specific i.Immunotherapy in which individual antigens are used in gradually increasing concentrations to stimulate an immune response, e.g., against particular allergic diseases or tumors.

Anyone who has suffered severe allergic reactions to an antigen (such as angioedema or anaphylaxis) should be considered for treatment with specific immunotherapy. After the administration of the antigen (such as yellow jacket and hornet venoms in patients allergic to insect stings), the patient should be closely monitored for evidence of difficulty in breathing, palpitations, urticaria, angioedema, changes in blood pressure, dizziness, faintness, or changes in mental status. Periodic monitoring of vital signs, oximetry, and breath sounds is required to ensure stability. Patients can usually be discharged if they have experienced no untoward effects 30 min after administration. Epinephrine should be available for immediate injection if the patient develops an anaphylactic reaction.

stimulation i.The therapeutic use of agents that stimulate immune function (immunostimulants). These agents include cytokines and cytokine antagonists, monoclonal antibodies, compounds obtained from bacteria, and hormones from the thymus. The most successful immunostimulants have been laboratory-prepared cytokines, the protein mediators of immune responses. Granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor are used widely to increase white blood cell production in the bone marrow after cancer therapy, bone marrow transplantation, and AIDS. Erythropoietin is effective in treating anemia in patients with chronic renal failure, AIDS, and bone marrow depression following cancer therapy. Transforming growth factor beta seems to enhance healing of wounds and reduce fibrotic changes following inflammation. Interleukins and interferons are being studied for their beneficial effects in patients with certain leukemias and other malignant tumors. Lymphocyte-activated killer cells and tumor-infiltrating lymphocytes, which are lymphocytes that have been removed from the patient and stimulated with interleukin-2, also show promise in treating malignant tumors. Monoclonal antibodies against mediators of inflammation have been created in the laboratory from hybridomas and are being studied for clinical use.

Bacteria-based compounds, which produce nonspecific stimulation, have been used the longest. Weak solutions of Mycobacterium bovis (bacille Calmette-Guérin) and endotoxins from Staphylococcus aureus and OK432, prepared from Streptococcus pyogenes, are being used as adjunct cancer therapy because of their ability to activate natural killer cells, T cells, and macrophages. New techniques have enabled researchers to isolate hormones from the thymus gland , where T lymphocytes mature, to treat viral infections and cancers. Their clinical effectiveness has not been established.

SEE: cytokine; monoclonal antibody.

subcutaneous i.Any extract derived from an allergen and dissolved in water and used for subcutaneous injection.

sublingual i.

ABBR: SLIT

Allergen desensitization in which the antigen is administered in droplet form under the tongue instead of being injected subcutaneously. SLIT is a relatively safe form of immunotherapy and is often used at home instead of in a medical office, several times a week.

Adverse effects include oral itching or swelling and gastrointestinal upset. The incidence of systemic side effects may be reduced with SLIT as opposed to immunotherapy by subcutaneous injection.

suppressive i.Any treatment used to block abnormal or excessive immune responses.

Corticosteroids, the most widely known anti-inflammatory agents, increase the number of neutrophils in the blood but decrease their aggregation at inflammatory sites, decrease the number and function of other white blood cells, and inhibit cytokine production. They are most effective during an acute flareup of a chronic autoimmune disease and in conjunction with other agents because they do not adequately block autoantibodies when used alone.

Cytotoxic drugs kill all white blood cells and their precursors and were originally developed as anticancer agents. However, low-dose methotrexate is now known to be effective in reducing the symptoms and the need for corticosteroids in chronic inflammatory diseases such as rheumatoid arthritis, Crohn disease, psoriasis, and asthma.

Cyclosporine and tacrolimus are related to the cytotoxic drugs, but these drugs selectively inhibit helper T-cell production of interleukin-2, effectively preventing replication rather than killing them. They are used extensively to prevent rejection of transplanted tissue and graft-versus-host disease.

Intravenous gamma globulin (IVIG) is used routinely to replace antibodies in patients with immunodeficiency disorders. It also can be used as an immunosuppressive. IVIG inhibits phagocytosis of platelets in idiopathic thrombocytopenic purpura. It has been most successful in the treatment of children but also can produce a short-term remission in adults. Because it seems to inhibit natural killer cells and augment suppressor T cells, it also has been used to treat other autoimmune diseases, but its clinical effectiveness has not been determined.

Antilymphocyte antibodies inhibit the T-cell–mediated immune response. The two types are monoclonal antibodies, which react with one specific antigen, and polyclonal antibodies, which target several different antigens. Polyclonal antibodies are created by injecting animals (usually mice) with human lymphocytes. The animals' B cells are harvested from lymphoid tissue or peripheral blood and used to create antilymphocyte serum (ALS); isolated antibodies from these B cells are the active agents in antilymphocyte globulin (ALG). Both ALS and ALG are used routinely to treat transplant rejection and graft-versus-host reactions. ALS and ALG come from animals and can cause serum sickness; moreover, they are not specific to T cells, and they can also destroy platelets.

Monoclonal antibodies are laboratory-created antibodies developed from a single cell line that block the receptor molecules that bind and transfer cytokine signals on T cells. OKT3, a monoclonal antibody obtained from mice, is a strong immunosuppressant used in the primary treatment of acute transplant rejection; it also may be effective in preventing rejection. OKT3 frequently causes a massive release of cytokines whose effects must be controlled, usually by corticosteroids, after the first or second dose. In addition, over time it stimulates the production of antimouse antibodies that block its effectiveness. Monoclonal antibodies provide disease or tumor-specific therapy for various autoimmune illnesses and cancers by selectively binding to tumor cell surfaces. Interleukin's effects are exerted on the T lymphocytes. Interferons have antiviral, antiproliferative and immunomodulary effects.

SEE: hybridoma.

Plasmapheresis, the separation and removal of plasma containing autoantibodies (AAb), is most effective against disorders in which the AAbs are tissue specific, such as myasthenia gravis, and those in which more AAbs are found in the blood than in extravascular spaces.

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Many immunosuppressant drugs increase patients' susceptibility to infections (such as the reactivation of tuberculosis) or the new acquisition of opportunistic infections. Some also increase the risk of developing malignant tumors, because of the loss of immunosurveillance.

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Patients must learn to minimize their exposure to infectious organisms and be consistent in good hand and oral hygiene. The medication regimen may be rigorous and should be accompanied by instruction about desired effects and side effects of the drugs and the need for frequent bloodwork; written and oral instructions about the treatment regimen are often provided to the patient.

venom i.

ABBR: VIT

Desensitization to stinging bee and wasp allergy.