immune response Flashcards
third line of defence: characteristics
- specificity
- memory
- inducible
- self-tolerance
- two arms
specificity
pathogen specific response
memory
long term protection
inducible
vaccinations
self-tolerance
identifies substances that are self
two areas
humoral
cellular
Humoral (antibody mediated)
B cells
produces antibodies
bacteria and viruses
Cellular
- T cells
- reacts directly with antigen (protein) on cell surface
- viruses and cancer cells
hypersensitive
- excessive or inappropriate immune response that results in disease of damage to the host
- includes allergy, autoimmunity and alloimmunity
- may be either antibody mediated or cell mediated
allergy
harmful effects of hypersensitivity to environmental antigens
autoimmunity
disturbance in the immunologic tolerance of self-antigens
- breakdown of self-tolerance
- body recognizes self-antigen as foreign
alloimmunity
immune reaction to tissue of another indiviual
ex.transplant
type 1
IgE mediated/ mast cells drgranulate
type 2
IgM, IgG mediated
antigen-antibody complex forms on the cell
type 3
IgM, IgG mediated
antigen-antibody complexes formed in circulation and later deposited in different tissues
type 4
cell mediated (T cells)
type 1 allergy
- against environmental antigens
- IgE binds to receptors on surface of mast cells
- subsequent exposure: histamine
- typical allergens include pollens, molds, fungi, foods, animals and house dust
- skin, respiratory and GI tract have a large number of mast cells
type 1 manifestations
itching urticaria (hives) conjunctivitis rhinitis edema GI cramps and malabsorption
type 1 anaphylactic reaction
- genetic disposition
- life threatening allergic reaction (wheezing, hypotension and GI)
RX.main: epinephrine other: coricosteriods and antihistamine
type 2
- immune response to proteins only on certain cell’s membranes
- cells are lysed or phagocytize
hemolytic disease of the newborn
occurs with a mom who is Rh- and baby is Rh+
- during delivery of first baby, mom exposed to Rh factor
- injection of Rh immune during pregnancy to prevent formation of antibodies
- if antibodies do form:
mild - jaundice
severe - miscarriages
type 3 autoimmunity
- lupus
- arthus reaction (localized)
- serum sickness
systemic lupus erythematosus (SLE)
- antigen-antibody complexes form and circulate in plasma
- complexes are then deposited in various tissues and organs
- skin, muscle and bone, heart, kidney, lungs, reproductive organs and nerves
- common in females
- butterfly rash
type 4 transplant rejection
can be prevented by:
- tissue typing (HLA)
- immunosuppressive techniques
(corticosteroids, cytotoxic, anti-lymphocyte serum)
immune deficiencies
- inefficient immune responce mechanisms of self-defence
- primary or secondary
- b cell or t cell
clinical hallmark of immune deficiencies
unusual, recurrent or severe infections
- complete blood count with WBD differential
- immunoglobin measurement
- CD4, CD8
Primary deficiency
DiGeorge Syndrome
DiGeorge Syndrome
- partial lack of thymus
- structural defects in heart and aorta
- distinctive facial characteristics
secondary (acquired) deficiencies
- more common than primary deficiencies
- normal physiology conditions/aging
General treatment for immunodeficiencies
- gamma globulin therapy
- transplantation
(bone marrow, thymus transplantation, stem cell)
Acquired immunodeficiency syndrome (AIDS)
caused by HIV
- depleted the body’s CD4 T-helper cells
- CD4 t cells needed for development of both plasma cells (antibodies) and cytotoxic T cells
AIDS/HIV
effective antiviral therapies have made AIDS/HIV a chronic disease
AIDS/HIV epidemiology
- blood-borne pathogen transmitted through sexual contact, blood to blood contract and through placenta, contract with blood at birth, or through breastfeeding
- increasing faster in woman than men
HIV stages
- acute infection
- clinical latency
- AIDS
stage: acute infections
- within 2-4 weeks of infection
- flu-like symptoms
- antibody usually appears within 4-7 weeks of exposure
(can remain zero-negative 6-14 months)
stage: Clinical latency
- asymptomatic
- with treatment, may last several decades
stage: AIDS
vulnerable to infections and cancers
HIV diagnosis
presence of the virus
decreased CD4 T-helper cells
AIDS diagnosis
opportunistic infections and cancers
stress and immune response
- stress directly influences immunity
- direct innervation to thymus, spleen, lymph nodes, lymphoid tissue and bone marrow
- increased cortisol, norepinephrine and epinephrine secretion during stress
increased chemicals cause
- cause atrophy of the thymus T cells (less resistance to infections, cancer)
- increases antibody response B cell (increased allergy and autoimmune responses)
- may enhance or suppress inflammatory response (different stressors have variable effects)
