Immunotherapy Health Dictionary

A term generally used to describe an adverse reaction by the body to any substance ingested by the affected individual. Strictly, allergy refers to any reactions incited by an abnormal immunological response to an ALLERGEN, and susceptibility has a strong genetic component. Most allergic disorders are linked to ATOPY, the predisposition to generate the allergic antibody immunoglobulin E (IgE) to common environmental agents (see ANTIBODIES; IMMUNOGLOBULINS). Because IgE is able to sensitise MAST CELLS (which play a part in in?ammatory and allergic reactions) anywhere in the body, atopic individuals often have disease in more than one organ. Since the allergic disorder HAY FEVER was ?rst described in 1819, allergy has moved from being a rare condition to one a?icting almost one in two people in the developed world, with substances such as grass and tree pollen, house-dust mite, bee and wasp venom, egg and milk proteins, peanuts, antibiotics, and other airborne environmental pollutants among the triggering factors. Increasing prevalence of allergic reactions has been noticeable during the past two decades, especially in young people with western lifestyles.

A severe or life-threatening reaction is often termed ANAPHYLAXIS. Many immune mechanisms also contribute to allergic disorders; however, adverse reactions to drugs, diagnostic materials and other substances often do not involve recognised immunological mechanisms and the term ‘hypersensitivity’ is preferable. (See also IMMUNITY.)

Adverse reactions may manifest themselves as URTICARIA, wheezing or di?culty in breathing owing to spasm of the BRONCHIOLES, swollen joints, nausea, vomiting and headaches. Severe allergic reactions may cause a person to go into SHOCK. Although symptoms of an allergic reaction can usually be controlled, treatment of the underlying conditon is more problematic: hence, the best current approach is for susceptible individuals to ?nd out what it is they are allergic to and avoid those agents. For some people, such as those sensitive to insect venom, IMMUNOTHERAPY or desensitisation is often e?ective. If avoidance measures are unsuccessful and desensitisation ine?ective, the in?ammatory reactions can be controlled with CORTICOSTEROIDS, while the troublesome symptoms can be treated with ANTIHISTAMINE DRUGS and SYMPATHOMIMETICS. All three types of drugs may be needed to treat severe allergic reactions.

One interesting hypothesis is that reduced exposure to infective agents, such as bacteria, in infancy may provoke the development of allergy in later life.

Predicted developments in tackling allergic disorders, according to Professor Stephen Holgate writing in the British Medical Journal (22 January 2000) include:

Identi?cation of the principal environmental factors underlying the increase in incidence, to enable preventive measures to be planned.

Safe and e?ective immunotherapy to prevent and reverse allergic disease.

Treatments that target the protein reactions activated by antigens.

Identi?cation of how IgE is produced in the body, and thus of possible ways to inhibit this process.

Identi?cation of genes affecting people’s susceptibility to allergic disease.... allergy

The study of immune responses to the environment. Its main clinical applications include improving resistance to microbial infections (see IMMUNITY), combating the effects of impaired immunity (see IMMUNODEFICIENCY), controlling harmful immune reactions (see ALLERGY), and manipulating immune responses (see IMMUNOTHERAPY) to prevent harmful immunological responses such as graft rejection and autoimmune diseases (see AUTOIMMUNITY). The clinical study of disordered immunity now forms the allied discipline of clinical immunology, which is closely linked to the laboratory-based discipline of immunopathology.... immunology

An agent that stimulates either innate or acquired immunity. In the U.S., immunotherapy is relegated to experimental medicine, but a number of plant substances are used in Europe as immunostimulants. The presumption of immunostimulation is that you increase native resistance and let it run its course. American Standard Practice, with all good intentions, tends to aggressive procedures, and feels empowered only when intervening against, not with, physiologic responses. Medicine is the only approach to many problems, but in the U.S. we all tend to forget that our brand of standard practice is uniquely aggressive and invasive amongst the industrialized nations. There are other ways...which is presumably why you are using this glossary in the first place.... immunostimulant

any treatment that facilitates the ability of the immune system to fight disease, as opposed to acting directly against the disease (compare chemotherapy; radiotherapy). Such treatments, most commonly used for cancer and rheumatic disease, include *biological response modifiers, *immunotherapy, *monoclonal antibodies, *cytokine inhibitors and modulators, and *targeted agents.... biological therapy

A group of infections caused by parasites transmitted to humans by sand?ies.

Visceral leishmaniasis (kala-azar) A systemic infection caused by Leishmania donovani which occurs in tropical and subtropical Africa, Asia, the Mediterranean littoral (and some islands), and in tropical South America. Onset is frequently insidious; incubation period is 2–6 months. Enlargement of spleen and liver may be gross; fever, anaemia, and generalised lymphadenopathy are usually present. Diagnosis is usually made from a bone-marrow specimen, splenic-aspirate, or liver-biopsy specimen; amastigotes (Leishman-Donovan bodies) of L. donovani can be visualised. Several serological tests are of value in diagnosis.

Untreated, the infection is fatal within two years, in approximately 70 per cent of patients. Treatment traditionally involved sodium stibogluconate, but other chemotherapeutic agents (including allupurinol, ketoconazole, and immunotherapy) are now in use, the most recently used being liposomal amphotericin B. Although immunointact persons usually respond satisfactorily, they are likely to relapse if they have HIV infection (see AIDS/HIV).

Cutaneous leishmaniasis This form is caused by infection with L. tropica, L. major,

L. aethiopica, and other species. The disease is widely distributed in the Mediterranean region, Middle East, Asia, Africa, Central and South America, and the former Soviet Union. It is characterised by localised cutaneous ulcers

– usually situated on exposed areas of the body. Diagnosis is by demonstration of the causative organism in a skin biopsy-specimen; the leishmanin skin test is of value. Most patients respond to sodium stibogluconate (see above); local heat therapy is also used. Paromomycin cream has been successfully applied locally.

Mucocutaneous leishmaniasis This form is caused by L. braziliensis and rarely L. mexicana. It is present in Central and South America, particularly the Amazon basin, and characterised by highly destructive, ulcerative, granulomatous lesions of the skin and mucous membranes, especially involving the mucocutaneous junctions of the mouth, nasopharynx, genitalia, and rectum. Infection is usually via a super?cial skin lesion at the site of a sand?y bite. However, spread is by haematogenous routes (usually after several years) to a mucocutaneous location. Diagnosis and treatment are the same as for cutaneous leishmaniasis.... leishmaniasis

(malignant melanoma) n. a highly malignant tumour of melanin-forming cells, the *melanocytes. Such tumours usually occur in the skin (pale skin, genetic predisposition, and excessive exposure to sunlight, particularly repeated sunburn, are the most important factors); it may arise from a pre-existing mole or naevus or from apparently normal skin. It can rarely occur at other sites than the skin. Melanomas are usually dark, but may also be free of pigment (amelanotic melanomas). Spread of this cancer to other parts of the body, especially to the lymph nodes and liver, is common if the original melanoma is thick. The prognosis is inversely related to the thickness of the tumour; almost all patients with tumours less than 0.76 mm survive following surgical excision. The mainstay of treatment is surgery, but melanoma can be responsive to *immunotherapy and is currently the subject of investigational treatments using melanoma vaccines; the response rate to conventional chemotherapy is poor. Primary prevention programmes reducing episodes of sunburn are advanced in some parts of the world, such as Australia.... melanoma

n. inflammation of the lining of the nose and paranasal sinuses. Rhinosinusitis is a common condition caused by allergies, infection, immune deficiencies, *mucociliary transport abnormalities, trauma, drugs, or tumours. Various classifications exist. The European Position Paper on Rhinosinusitis and Nasal Polyps 2012 defined acute rhinosinusitis as lasting up to 12 weeks and chronic rhinosinusitis as lasting 12 or more weeks. Subgroups of the latter include chronic rhinosinusitis with and without nasal polyps and allergic fungal rhinosinusitis. Treatment may require steroids (topical or systemic), antibiotics, immunotherapy, or *endoscopic sinus surgery. See rhinitis; sinusitis.... rhinosinusitis

n. a benign growth on the skin caused by infection with *human papillomavirus (a few of the many serotypes are *oncogenic). Common warts are firm horny papules, 1–10 mm in diameter, found mainly on the hands. Most will clear spontaneously within two years. Plantar warts (or verrucae) occur on the soles and are often tender. Plane warts are flat and skin-coloured – and therefore difficult to see; they are usually found on the face and may be present in very large numbers. Anogenital warts are frequently associated with other genital infections (see condyloma). Treatment of warts is with OTC (over-the-counter) remedies, such as lactic and salicylic acids; *cryotherapy with liquid nitrogen is also effective. Curettage and cautery is very occasionally used, as well as immunotherapy with diphencyclopropenone.... wart