Ch 6: Diseases of the Immune System Flashcards
what is innate (natural) immunity
intrinsic mechanisms that are poised to react immediately and are the first line of defense against microbes and damaged cells
include inflammation and antiviral defense
what is adaptive (aquired) immunity
mechanisms that are stimulated by exposure to microbes and other foreign substances
define immunity
your body’s reaction against cancers, tissue transplants, and self antigens
what are the 6 main cell types involved in innate immunity
epithelial
monocytes
neutrophils
plasma proteins
dendritic cells
innate lymphoid cells - natural killer cells
explain the inflammation portion of innate immunity
cytokines and complement proteins trigger vascular and cellular componenets of inflammation
leukocytes destroy microbes as well as ingest and eliminate damaged cells
helps to repair damaged tissues
explain the antiviral defense portion of innate immunity
type 1 interferons act on infected cells and activate enzymes that degrade viral nucleic acids and inhibit viral replication
what are the two main cell types of adaptive immunity
T lymphocytes and B lymphocytes
what are the three types of T lymphocytes
helper T
killer (cytotoxic) T
regulatory T
what do helper T lymphocytes do
stimulate B lymphocytes to make antibodies and activate other leukocytes to destroy microbes
what are the two primary lymphoid organs
thymus and bone marrow
what are the 3 types of secondary lymphoid organs
nodes
spleen
mucosal and cutaneous (tonsils and adenoids)
thymus (6-25yrs)
25g
thymus (26-35yrs)
20g
thymus (36-65yrs)
16 g
thymus (65+ yrs)
6g
what color is most lymphoid tissue under the microscope and why
very purple because lots of lymphocytes
spleen (16-20yrs)
150-200g (170g)
spleen (20-65yrs)
155g
spleen (80+yrs)
100g
what is a splenuculus
accessory spleen
ususally 1-2cm
where are peyer’s patches found
in the GI tract
what are the four main types of immunologic disorders
hypersensitivity
autoimmune
immunologic deficiency syndrome
amyloidosis
define atopy
tendency to develop immediate hypersensitivity reactions
what three things that hypersensitivity reactions can be caused by
exogenous and endogenous antigens
susceptible genes
imbalance between effector mechanisms of immune responses and control mechanisms that serve to normally limit response
what is immediate (type 1) hypersensitivity
rapid reaction occuring in minutes anfter antigen binds
IgE antibody is produced
vasoactive amines (histamine) and other mediators from mast cells are released
recruitment of inflammatory cells
leads to vascular dilation, edema, smooth muscle contractions, and inflammation
ex. anaphylaxis, allergies, and asthma
what is antibody-mediated (type 2) hypersensitivity and what are two examples
production of IgG and IgM which bind to antigen on target cell
cell is phagocytosed, inflammed, or its functions disturbed
ex. autoimmune hemolytic anemia and Goodpasture syndrome
what is immune complex mediated (type 3) hypersensitivity - give three examples
deposition of antigen-antibody complexes
leads to fever, inflammation, tissue damage, lymph node enlargement, and necrotizing vasculitis (fibrinoid necrosis)
ex. system lupus, serum sickness, and glomerulonephritis
what is cell-mediated (type 4) hypersensitivity and give four examples
cell-mediated hypersensitivity
activated T lymphocytes release cytokines which cause inflammation
destruction by cytotoxic T cells also can cause inflammation
ex. contact dermatitis, multiple sclerosis, type 1 diabetes, and TB
what is autoimmune hemolytic anemia
an example of a type 2 hypersensitivity reaction
immune system mistakes red blood cells as unwanted substance
your body produces antibodies that destroy red blood cells which leads to anemia
what is Goodpasture syndrome and what are the two things it presents with
an example of a type 2 hypersensitivity reaction
antibodies against collagen in the glomeruli and alveolar basement membrane
presents with: hematuria (blood in urine) and hemoptysis (coughing up of blood)
what is anti-glomerular basement membrane antibody (ABMA)
antibody in Goodpasture Syndrome
what is crescentic glomerulonephritis
seen in Goodpasture syndrome
crescent shape collection of collagen in bowman’s capsule of glomeruli of the kidneys
what are the three phases of immune complex mediated (type 3) hypersensitivity
formation of immune complex
deposition of the immune complexes in various tissues
inflammatory reaction dispered through the body
what is an Arthus reaction
an example of a type of immune complex mediated (type 3) hypersensitivity
localized area of tissue necrosis resulting from acute immune complex vasculitis
what is an example of delayed-type hypersensitivity
type 4 hypersensitivity
tuberculin reaction from injection of purifed protein derivative made of a protein-containing antigen of the tubercle bacillus
what percentage of the population has an autoimmune disease
5-10%
why are women of childbearing age more likely to get an autoimmune disease
estrogen may reduce apoptosis of self-reactive B cells
what is systemic lupus erythematosus (SLE) and what does it present with
a type of autoimmune disorder that affects 1 in 500
antigen-antibody complexes damage multiple tissues
get production of autoantibodies
half have renal involvement - diffuse lupus nephritis
can have libman-sacks endocarditis
presents with: malar butterfly rash, alopecia, synovitis, and discoid rash
what is diffuse lupus nephritis
occurs in 50% of patients with systemic lupus erythematosus
glomeruli show proliferation of endothelial, mesangial, and epithelial cells that fill Bowmann’s space
shows wire loop on light microscopy
what is Libman-Sacks (murantic or verrucous) endocarditis
a form of nonbacterial thrombotic endocarditis (NBTE)
sterile vegetations on cardiac valves due to endothelial injury
seen in those with systemic lupus erythematosus
what is Sjogren Disease
chronic disease due to lymphocytic infiltration and fibrosis of the lacrimal and salivary glands
leads to: keratoconjunctivtis sicca (dry eyes) and xerostomia (dry moth)
what is systemic sclerosis (scleroderma)
disease of excessive dense collagen deposition in the dermis
possible result of autoimmunity
widespready damage to small blood vessels
progressive interstital and perivascular fibrosis in skin and multiple organs such as the GI tract (EGJ specficially)
Raynaud’s disease is a symptom of this disease
what is the Raynaud Phenomenom
numbness and tingling of the fingers and toes caused by episodic vasoconstriction of arteries and arterioles
characteristic of systemic sclerosis (scleroderma)
what happens in hyperacute rejection of the kidney
immediate
cyanotic, mottled, and anuric kidney
arteries have fibrinoid necrosis in lumen
kidney eventually undergoes outright necrosis
what is rejection
the process in which T lymphocytes and antibodies are produced against graft antigens react against and destroy tissue
three types: hyperacute, acute, and chronic
what happens in acute rejection of the kidney
days or weeks
cytotoxic T-cells start destroying graft cells
helper T-cells release cytokines which produce inflammation that damages grade cells
shows up with wavy basement membranes in the tubules
what happens in chronic rejection of the kidney
months or years
interstitial fibrosis and gradual narrowing of the graft blood vessels
what are primary immunodeficiencies
inherited defects in the early innate immune response typically affect leukocyte functions or the complement system
all lead to increased vulnerability to infections
what are the two main types of secondary immunodeficiencies (aquired)
HIV and amyloidosis
what is DiGeorge Syndrome (Thymic Hypoplasia) and what is it caused by
a type of primary immunodeficiency
T-cell deficiency that results from failure of development of the thymus
usually caused by a small germline deletion that maps to chromsome 22q11
what is Wiskott-Aldrich Syndrome (WASp protein)
a type of primary immunodeficiency
X-linked disease in the WAS protein
leads to increase susceptibility to infections and anemia
what does WASp do
it’s a key actin cytoskeleton regulator that coordinates the assembly of actin filaments in response to cell signaling event
what is selective IgA deficiency
most common type of primary immunodeficiency
impaired differentiation of naive B lymphocytes to IgA-producing plasma cells
leads to weakened mucosal defenses and infections in the respiratory, GI, and urogenital tracts
what is acquired immunodeficiency syndrome (AIDS)
immunosupressions that leads to infections and cancers
second leading cause of dead in US men
what are the three ways in which you can get HIV
sexual transmission (most common)
parenteral transmission (blood transfusions)
mother-to-infant (vaginal birth or ingestion of breast milk)
what is human immunodeficiency virus (HIV)
human retrovirus from the lentivirus family
infects memory and activated T cells
loss of memory cell has ripple effects on every componenet of immune system
what is candidiasis
most common fungal infection in patients with AIDS
what is Kaposi sarcoma
most common neoplasm in patients with AIDS
proliferation of spindle-shaped cells with intervening blood filled channels
90% of patients demonstrate some form of neurologic involvement (usually progressive encephalopathy) at autopsy when they have which disease
HIV
what disease has the highest risk after a needlestick
Hepatitis C virus (HCV)
what is amyloidosis
type of secondary immunodeficiency
inherited and inflammatory disorders in which extracellular deposits of fibrillar proteins (amyloid) cause tissue damage
amyloidosis condition caused by abnormal folding of proteins
which stain tests for amyloidosis
congo red
what is sago spleen
uniform enlargement of white pulp in spleen due to amyloid deposits
multiple tiny pearl like appearance of spleen
