Immune

Urticaria

(hives) is a cutaneous reaction against systemic allergens occurring in atopic persons. It is characterized by transient wheals (pink, raised, edematous, pruritic areas) that vary in size and shape and may occur throughout the body. Urticaria develops rapidly after exposure to an allergen and may last minutes or hours. Histamine causes localized vasodilation (erythema), transudation of fluid (wheal), and flaring. Flaring is due to blood vessels on the edge of the wheal dilating in response to a reaction augmented by the sympathetic nervous system. Histamine is responsible for the pruritus associated with the lesions.

Multiple chemical sensitivities (MCS)

)- This is an acquired disorder in certain people exposed to various foods and chemicals in the environment that have many symptoms related to multiple body systems (usually subjective). MCS is worse in women and symptoms include: headache, nausea, pain, IBS, dizziness, mouth irritation, disorientation and cough. Odor seems to be the primary trigger for MCS although many things can such as water, food additives, drugs, gas exhaust, perfume, etc. The causes of MCS are thought to be immunologic, psychological, toxicological and socioeconomic factors. To determine if MCS is happening, a CBC, lymphocyte subsets and antibody titers are drawn. Also, a provocation-neutralization test can be done where they purposefully expose the patient to the suspected allergen at a larger and larger dose, then dose strength dissipates, noting when peak and decline are seen. The most effective treatment of MCS is to avoid the chemicals that may trigger the symptoms and to create a chemical-free and odor-free home/work place. Also, regular exercise, P.T., massage, prayer and meditation are noticeable treatments.

OSHA

)-a federal agency that protects workers from injury and illness in their places of employment, supports activities that minimize or eliminate exposure to infectious materials in the workplace. OSHA mandates that any employer whose employees could be exposed to potentially infectious materials implement standard policies and procedures for protection of those employees.

Chain of infection

- Infective agent, reservoir, port of exit, mode of transmission, portal of entry and suseptible host.

Immunocompetence

- ability of the body's immune system to respond to pathogenic organisms and tissue damage; ability may be diminished by drugs specifically developed to inhibit immune cell function (e.g. chemotherapeutic agents used to treat leukemia and drugs used to prevent organ transplant rejections), by diseases that attack elements of the immune system, or overwhelming infections

Standard precautions

- applies to all boold and body fluid except sweat. This precaution protects the client and the health care staff.

Bacteremia

- bacteria in the blood stream.

Leukopenia

- refers to decrease in the total WBC count (granulocytes, monocytes and lymphocytes).

Autoimmunity

An immune response against self. Autoimmunity occurs when the body cannot differentiate between self and non-self. Certain immune cells that are normally dormant become activated for an unknown reason. B and or T cells can be affected, they cannot recognize our own self cells and therefore pathophysiological tissue damage occurs. There are two key links in activating these cells and developing an autoimmune disease, these two factors are: 1) inheritance of susceptibility gene, which contributes to failure of self-tolerance. 2) Initiation of autoreactivity by triggers, such as infections, which may activate self-reactive lymphocytes. Basically, a person is usually predisposed to getting an autoimmune disease (i.e. age, gender, family history) but, there has to be a key to switch on the autoimmunity (i.e. Virus).

Autoimmune disease

Can be either organ-specific or systemic. Examples of organ-specific: autoimmune hemolytic anemia, immune thrombocytopenic purpura. Systemic: systemic lupus erythematosus (SLE), rheumatoid arthritis, progressive systemic sclerosis (scleroderma), mixed connective tissue disorder. In example of a systemic disease, SLE affects women 20-40 years old, hitting multiple organs. The etiology is unknown but, it appears that the body has a loss of self-tolerance for the body's own DNA antigens. Apheresis is an effective treatment for autoimmune diseases, they take blood and filter it, removing many of the components they need, leukocytes, platelets, etc. Or plasmapheresis where they remove the plasma and filter through to catch any foreign matter.

Secondary immunodeficiency

Drug-induced immunosuppression is the most common. Immunosuppressive therapy is prescribed is prescribed for patients to treat autoimmune disorders and to prevent transplant rejection. In addition, immunosuppression is a serious side effect of chemotherapy drugs. Generaly, leukopenia often results, leading to a decreased humoral and cell-mediated response. Secondary infections are common in immunosuppressed patients.

Carrier

Individual who carries a copy of a mutated gene for a recessive disorder

Food infection

Is caused by eating food containing a large number of diease producing bacteria. Symptoms usually start 12 to 36 hours after ingestion.

Atopic

Sensitivity to environmental allergens

Hypersensitivity reaction

Sometimes the immune response is overreactive against foreign antigens or reacts against its own tissue, resulting in tissue damage.

T suppressor cells

T cells that close down the immune response after invading organisms are destroyed;Suppressor T cells are sensitive to high concentrations of circulating lymphokine hormones, and release their own lymphokines after an immune response has achieved its goal. This signals all other immune-system participants to cease their attack. Some memory B-cells remain after this signal to ward off a repeat attack by the invading organism

Pathogenicity

The ability of a pathogen to produce a disease in a organism.

Wheal and flare reaction

The response within 10 to 15 min to an antigen injected into the skin. The injected skin elevates and blanches, and becomes surrounded by a red rim of inflamed tissue.

B lymphocytes

These are also known as bursa equivalent lymphocytes, and they are produced in the bone marrow. B cells differentiate into plasma cells when activated. Plasma cells produce antibodies (immunoglobulins)

RAST

This is an acronym for the radioallergosorbent test. It is used for vitro diagnostic test for IgE antibodies to specific allergens. This test is safer than other skin tests but, it takes longer and is less sensitive. This test is helpful in determining reactivity to various foods or drugs in individuals with history of severe anaphylactic reactions.

Immunodeficiency

When the immune system does not adequately protect the body. For this to happen two or more immune mechanisms will be impaired 1) phagocytosis 2) humoral response 3) cell-mediated response 4) complement 5) combined humoral and cell-mediated deficiency. Immunodeficiency is considered primary (more serious and rare) when/if the immune cells are properly developed or absent. It is considered secondary when/if the cells are improperly developed or absent. Four types of primary immunodeficient disorders: 1) phagocytosis 2) B-cell deficiency 3) T-cell deficiency 4) a combined B-cell and T-cell deficiency. Secondary immunodeficient disorders can be caused by: drugs, age, malnutrition, therapies, diseases/disorders or stress. These types are required to have immunosuppressant therapies.

Atopic dermatitis

a chronic, inherited skin disorder characterized by exacerbations and remissions. It is caused by several environmental allergens that are difficult to identify. Although patients with atopic dermatitis have elevated IgE levels and positive skin tests, the histopathologic features do not represent the typical, localized wheal-and-flare type I reactions. The skin lesions are more generalized and involve vasodilation of blood vessels, resulting in interstitial edema with vesicle formation.

Angioedema

a cutaneous lesion similar to urticarial (hives) but it develops in the lower layers of the skin and submucosa. This usually affects the eyelids, lips, tongue, larynx, hands, feet, GI tract and genitalia. The swelling usually starts in the face and moves to the airways and other body parts. Then, dilation and engorgement of the capillaries occurs with a release of histamine that causes the swelling. The outer part of the skin will appear to have a reddish hue, these may burn, sting or itch and cause acute abdominal pain if it is found in the GI tract. Swelling may occur suddenly or over several hours and usually last for 24 hours.

Localized infection

a localized infection is limited to a small area.

Opportunistic pathogen

a pathogen is any microorganism capable of producing illness. Opportunistic pathogen infects when aseptic techniques or sterile techniques are lacking.

Leukocytosis

agents released from damaged cells and accumulating WBCs are carried to the bone marrow. Increase WBC 11,000/mm3 and higher.

Hypersensitivity

an abnormal sensitivity to a stimulus of any kind

Anaphylactic reaction

an acute and life-threatening hypersensitivity (allergic) reaction to a sensitizing substance (e.g., drug, chemical, vaccine, food, insect venom). Usually an immediate reaction causes massive vasodilation, release of vasoactive mediators, and an increase in capillary permeability. As capillary permeability increases, fluid leaks from the vascular space into the interstitial space. Anaphylactic shock can lead to respiratory distress, because of laryngeal edema or severe bronchospasm, and circulatory failure, because of massive vasodilation. The patient experiences a sudden onset of symptoms, including dizziness, chest pain, incontinence, swelling of the lips and tongue, wheezing, and stridor. Skin changes include flushing, pruritus, urticaria, and angioedema. In addition, the patient may become very anxious and confused and feel an impending sense of doom.

Emerging infection

an emerging infection is an infectious disease whose incidence has increased in the past 2 years or threatens to increase in the immediate future. Examples of emerging infections are lyme disease and the ebola virus. Emerging infectious diseases can originate from unknown sources, from contact with animals, changes in known diseases or even biologic warfare.

Iatrogenic infection

are a type of health care-associated infections from a diagnostic or therapeutic procedure. For example, following a gastrointestinal endoscopy the client developed a P. Aeruginosa infection. Use basic infection prevention and control policies and procedures to reduce the incidence of HAIs

Natural killer cells (NK)

are also involved in cell-mediated immunity. These cells are not T or B cells, but are large lymphocytes with numerous granules in the cytoplasm. NK cells do not require prior sensitization for their generation. These cells are involved in recognition and killing of virus-infected cells, tumor cells, and transplanted grafts. The mechanism of recognition is not fully understood. NK cells have a significant role in immune surveillance for malignant cell changes

T cytotoxic cells

are involved in attacking antigens on the cell membrane of foreign antigens on the cell membrane of foreign pathogens and releasing cytotoxic substances that destroy the pathogen. These cells have antigen specificity and are sensitized by exposure to the antigen. Similar to B lymphocytes, some sensitized T cells do not attack the antigen but remain as memory T cells. As the humoral immune response, a second exposure to the antigen will result in a more intense and rapid cell-mediated immune response.

T helper cells

are involved in the regulation of cell-mediated immunity and the humoral antibody response. T helper cells differentiate into subsets of cells that produce distinct types of cytokines. These subsets are TH1 cells and TH2 cells. TH1 cells stimulate phagocyte-medidated ingestion and killing of microbes, the key ingredient of cell-mediated immunity. TH2 cells stimulate phagocyte independent, eosinophil-mediated immunity, which is effective against parasites.

Transmission based precautions

are used for patients known to be or suspected of being infected with highly transmissible or epidemiologically important pathogens that require additional precautions to interrupt transmission and prevent infection.

Nosocomial/healthcare associated infection

associated infection is a HAI - hospital acquired infection. Most commonly E Coli, staph and C. Diff. Usually caused by ineffective handwashing or not washing hands, not using PPEs. UTIs, surgical wounds are common infections.They can occur from the result of invasive procedures, antibiotic administration, the presence of multidrug-resistant organisms, and breaks in infection prevention and control activities.

Anaphylaxis

can occur when mediators are released systemically (e.g., after injection of a drug, after an insect sting). The reaction occurs within minutes and can be life threatening because of bronchial constriction and subsequent airway obstruction and vascular collapse. Initial symptoms include edema and itching at the site of the exposure to the allergen. Shock can occur rapidly and is manifested by rapid, weak pulse; hypotension; dilated pupils; dyspnea; and possibly cyanosis. This is compounded by bronchial edema and angioedema. Death will occur if emergency treatment is not initiated.

Food intoxication

caused by the consumption of a food in which bacteria have produced a poisonous toxin

T lymphocytes

cells that migrate from the bone marrow to the thymus differentiate into T Lymphocytes. The thymus secretes hormones, including thymosin, that stimulate the maturation and differentiation of T lymphocytes. T cells compose 70% to 80% of the circulating lymphocytes and are primarily responsible for immunity to intracellular viruses, tumor cells, and fungi. T cells live from a few months to the life span of an individual and account for long-term immunity

Cell-mediated immunity

cells used: T cells, product: sensitized T cells cytokines, , has memory cells examples: TB, destruction of cancer cells.

Humoral immunity

consists of antibody-mediated immunity. cells used: B cells, products: antibodies, has memory cells. examples: anaphylactic shock, bacterial infection.

Innate (natural) immunity

exists in a person without prior contact with an antigen. This type of immunity involves a nonspecific response, and neutrophils and monocytes are the primary WBCs involved. One type of innate immunity is species-specificity of infectious agents. Humans are naturally immune to some of the infectious agents that cause illnesses in other people

Allergic rhinitis

hay fever, is the most common type I hypersensitivity reaction. It may occur year-round (perennial allergic rhinitis), or it may be seasonal (seasonal allergic rhinitis). Airborne substances such as pollens, dust, and molds are the primary cause of allergic rhinitis. Perennial allergic rhinitis may be caused by dust, molds, and animal dander. Seasonal allergic rhinitis is commonly caused by pollens from trees, weeds, or grasses. The target areas affected are the conjunctiva of the eyes and the mucosa of the upper respiratory tract. Symptoms include nasal discharge, sneezing, lacrimation, mucosal swelling with airway obstruction, and pruritus around the eyes, nose, throat, and mouth.

PPE

includes gloves,gowns,mask,eye protection. Gowns primary reason is te prevent soiling of your clothes. Keeps you from coming in contact with infected materials, blood or body fluid. Mask Used to protect any splashing or spraying to get on the face. Also used if there is droplet or airbourne pathogens. Eye protection is used to prevent any slpashing or spraying in the eyes.Gloves help to prevent transmission of pathogens directly or indirectly.

Mononuclear phagocyte system (MPS)

includes monocytes in the blood and macrophages found throughout the body. Mononuclear phagocytes have a critical role in the immune system. They are responsible for capturing, processing, and presenting the antigen to the lymphocytes. This stimulates a humoral or cell-mediated immune response. Capturing is accomplished through phagocytosis. The macrophage-bound antigen, which is highly immunogenic, is presented to circulating T and B lymphocytes and thus triggers an immune response.

Reemerging infection

infections that have come back after near eradications by medication and vaccines.

Antigen

is a substance that elicits an immune response. Most antigens are composed of protein. However, other substances such as large-size polysaccharides, lipoproteins, and nucleic acids can act as antigens. All of the body's cells have antigens on their surface that are unique to that person and enable the body to recognize itself. The immune system becomes "tolerant" to the body's own molecules and therefore is nonresponsive to "self" antigens.

Acquired immunity

is the development of immunity, either actively or passively. It is divided into active acquired immunity and passive acquired immunity.

Infection

is the invasion of the body by a pathogen (any microorganism that causes disease) and the resulting signs and symptoms that develop in response to the infection

Immunosuppression

is the suppression of the immune system. This can happen from certain diseases like AIDS or chemotherapy drugs.

Pruritus

itching that can indicate alterations in fluid balance. This can happen because of any physical or chemical stimulus to the skin (insect bites or drugs) and any scaling skin disorder. The itching sensation is from non-myelinated nerve fibers as pain. If the epidermis is damaged or absent, the sensation will be shown as pain rather than an itch. To calm the itching feeling, have the patient in a cool environment and to avoid itching. Constant itching from the pruritus can result in lichenification, a thickening of the skin.

Lymphocytes

lymphocytes are produced int he bone marrow. They differentiate into B & T lymphocytes.

Dendritic cells

make up a system of cells that are important to the immune system, especially the cell-mediated response. They have an atypical shape with extensive dendritic process that form and retract. They are found many places in the body, including the skin (where they are called Langerhaus cells) and the lining of the nost, stomach and intestine. Especially in the immature state, they are found the blood. They primarily function to capture antigens at sites of contact with the external environment.

Medical asepsis

or clean technique, includes procedures used to reduce the number of organisms present and prevent the transfer of organisms. Hand hygiene, using clean gloves to prevent the transfer of organisms from one client to another or to prevent direct contact with client blood or body fluids, and cleaning the environment routinely are examples of medical asepsis.

Secondary immune response

rapid, strong response by T and B cells to a second or subsequent appearance of an immunogen; this occurs because of the availability of T and B lymphocyte memory cells

Antibiotic resistant organism

resistance occurs when pathologic organisms change in ways that decrease the ability of a drug (or family of drugs) to treat disease. Microorganisms are highly adaptive. Genetic mechanisms include mutation and acquistition of new DNA or RNA. Biochemically, bacteria can resist antibiotics by producing enzymes that destroy or inactivate the drugs.

Immunity

responsiveness to foreign substances, such as microorganisms.

Cytokines

soluble factors secreted by WBCs snf other cells. They act as messengers between cell types and instruct cells to alter their proliferation, differentiation, secretion or activity. examples: Interleukins, interferons, erythropoietin, CSFs or TNF.

Surgical asepsis

sterile technique prevents contamination of an open wound, serves to isolate the operative area from the unsterile environment, and maintains a sterile field for surgery. Surgical asepsis includes procedures used to eliminate all microorganisms, including pathogens and spores, from an object or area. In surgical asepsis an area or object is considered contaminated if touched by any object that is not sterile.

Systematic infection

systemic infections are widespread throughout the body and are often spread via the blood

Immunisenscence

the age associated decline of the immune system and host defense mechanisms; elderly individuals frequently have a decline in cell-mediated immunity and secondary declines in humoral immunity; the clinician caring for the older patient can assume that the individual has defective host defenses, is at greater risk for developing an infectious disease, and has an increased risk of morbidity and mortality from infectious diseases

Primary immunodeficiency

the basic categories of primary immunodeficiency disorders are (1) phagocytic defects; (2) B-cell deficiency; (3) T-cell deficiency; (4) combined B-cell and T-cell deficiency.

Primary immune response

the initial reaction to an immunogen, during which T and B lymphocytes are activated and antibodies specific to the antigen are produced; reaction is considered relatively weak but produces large numbers of antigen-specific memory cells

immunotherapy

this is the recommended treatment for control of allergic symptoms when the allergen cannot be avoided and drug therapy is not effective. Immunotherapy use is very rare, indicated for persons with anaphylactic reaction to insect venom. The administration of the immunotherapy consists of small injections of a titer of the allergen with increasing dosage strength until a hyposensitivity is reached. In the meantime, the person should still be trying to avoid the allergen. The disadvantage of this treatment is that it is not always effective and it cannot be used on a person with a food allergy.

Central lymphoidorgans

thymus gland and bone marrow.

Peripheral lymphoid organs

tonsils, gut, genital, bronchial, and skin-associated lymphoid tissues, lymph nodes, and spleen

Colonization

when a microorganism is present and it grows or multiplies but does not cause infection.