CMA: Immunology and Allergies

allergen

substance capable of producing hypersensitive allergic reaction, even if it isn’t harmful to the body

antigen

foreign substance, typically made of protein that evokes allergic reaction; immune system reacts to deactivate, neutralize, or kill antigen

cell-mediated response

• T-cell lymphocytes produced

• response to some infections and malignancies

• part of delayed hypersensitivity reaction, several hours after exposure to an allergen

• involved when body rejects transplanted tissue

humoral immune response

• B-cell lymphocytes produced

• when body is exposed to an antigen and develops antibodies for the antigen

• specific to the antigen

nonspecific immune response

• causes inflammation in body tissue due to injury

• involves chemical, vascular, and leukocyte activities in tissues around injury

• results in redness in area of injury, swelling, pain, and warmth of tissues

specific immune response

• activates when inflammation is insufficient to manage infection

• response controlled by T-cell lymphocytes of cell-mediated response and B-cell lymphocytes of humoral immunity processes

lymphatic system

involved in immune response to pathogens and foreign bodies

thymus gland and bone marrow

responsible for developing lymphocytes

organs of lymphatic system

lymph glands, tonsils, and spleen

spleen

filters substances from the lymph and stimulates production of lymphocytes

neutrophils

• polymorphonuclear leukocytes (PMNs)

• specialized blood cells react to infection that threatens health of body cells

• protect body cells from damage

monocytes

• WBCs that mature into macrophages

• perform phagocytosis

• other phagocytes are called Kupffer cells that live in liver and lymph node reticular cells

eosinophils

• WBCs attracted to cells and parasites coated with C2B substances (e.g. helminths)

• secrete chemicals to erode walls of invading organism

basophils

• WBCs important in hypersensitivity reactions in allergic response

lymphocytes

• responsible for antigen-antibody response and sensitization (memory) to antigens of previous exposure

• includes B- and T-cells

B-Cells

• mature in bone marrow

• humoral/antibody-mediated immunity with T-cells

T-Cells

• frome bone marrow, mature in thymus gland

• cell-mediated immunity by itself

• humoral/antibody-mediated immunity with B-cells

natural immunity

inherited immunity

acquired immunity

results from being exposed to a disease or being immunized through vaccinations

active immunity

long-term immunity; often lasts for lifetime, immunization leads to active immunity

passive immunity

• short term

• administration of already formed antibodies instead of from body-created

• further vaccinations

• newborns have passive immunity for short time from transfer of mother’s antibodies through placenta

• breastfeeding continues passive immunity for longer, but must be vaccinated

immunodeficiency diseases

• occurs when immune system cannot fight disease and protect body

• immune system responds but not strong enough

• can be genetic, occur when body is weakened by chemotherapy or radiation, immunosuppressive drugs used during organ transplant, or disease

• when taking immunosuppressive drugs, WBCs ability decrease, increasing severity of normal infections to the body

autoimmune disorders

• when body receives part of its own body as foreign

• develops self-antigens to destroy “foreign” body part

• affects any body area including collagen, hematopoietic tissue, CV tissue, gastrointestinal sys, endocrine sys, renal sys, and nervous tissue

• tests assesses autoimmune system diseases

  • Coombs’ test assesses development of antibodies to hemolytic diseases

  • antinuclear antibody test diagnoses rheumatoid arthritis and other diseases

• prescribe steroids and immunosuppressive drugs to reduce body’s immune response

• therapy may be needed to help maintain functioning of muscles

hypersensitivity and allergy reactions

• body becomes inflamed

• organs becomes dysfunctional when foreign substance enters body

• hypersensitivity is an exaggerated histamine and other types of immune system response to the foreign substance

• allergic reaction develops after repeated exposure to antigen over time; symptoms vary on severity of reaction

autoimmune hemolytic anemia

• body does not recognize red blood cells and destroy it with B-cells

• destroys lymphocytes, leaving immune system unable to defend body from pathogens

• symptoms: weakness, fever, chills, dyspnea, bruising, pale skin color or jaundice

multiple sclerosis

• chronic or progressive neurological disorder

• affects myelin sheath

• caused by genetics or viral infection

• symptoms: double vision, muscle weakness, progressive lack of coordination leading to paralysis, numbness, prickling, tingling, dysphasia, incontinence, and severe mood swings

myasthenia gravis

• neuromuscular disease showing sporadic weakened muscles, especially after strenuous activity

• progresses to complete muscular and respiratory paralysis

• symptoms: fatigue, muscle weakness, double vision, ptosis, difficulty in swallowing, and backward flow of liquids through the nose

pernicious anemia

• inherited autoimmune blood cell production disorder

• results from a deficiency of intrinsic factor in which red blood cells develop abnormally when vitamin B12 is deficient

• symptoms: weakness, fatigue, pallor, light-headedness, tachycardia or palpitations, nausea, vomiting, neuritis, numbing or tingling feeling in extremities

rheumatoid arthritis

• chronic disease

• causes inflammation and destruction of synovial membranes of joints

• cartilage and bone erode over time and become deformed

• symptoms: joint pain, low-grade fever, fatigue, malaise, and weight loss

systemic lupus erythematosus

• chronic systemic disorder that can affect connective tissue throughout the body

• high mortality rate with five years of onset

• symptoms: butterfly rash on face, fever, malaise, weakness, weight loss, photosensitivity, joint pain, pleuritis, carditis, hair loss, and ulcerations in oral cavity

hay fever

seasonal respiratory reaction to allergens like pollen

asthma

serious resp reaction in which bronchial tubes constrict, causing serious breathing difficulties

urticaria

spreading of reddened and elevated lesions (hives)

food allergies

result in potential life-threatening immune response to specific foods

anaphylaxis

• anaphylaxis response

  • severe antigen-antibody reaction to repeated exposure to an allergen

  • can be life-threatening

  • antigen triggers production of antibodies which trigger immune response

• anaphylactic shock

  • life-threatening response in which A-A reaction leads to a closed airway

  • immediate emergency care is required

  • many carry an epi-pen with them at all times

  • epinephrine in pen gives time for EMS to intervene after exposure to substance

allergy testing

• intradermal

  • small amount of potential antigen is injected under skin

  • if allergic, area will show immune response

• skin patch

  • patch soaked with potential antigen on skin; several tested at once

  • if allergic, area will show immune response

• scratch testing

  • potential antigen placed into scratch made on skin; several tested at once

  • if allergic, area will show immune response

• CBC

  • complete blood count

  • look at RBCs, platelets, and WBCs

  • different WBCs will increase with allergic response