Alterations in Immunity and Inflammation Flashcards
alloimmunity
examples?
alloimmunity: directed against beneficial foreign tissues (transfusions, transplants, transient neonatal alloimmunity)
transient neonatal alloimmunity: fetus expressing parental antigens not found in the mother (Rh factor)
Type I Hypersensitivity
Receptors
s/s
IgE mediated, anaphylaxis (urticaria + bronchospasm), allergy
H1 & H2 receptors
H1 - bronchial constriction, edema, vasodilation
H2 - increased gastric secretions, decrease release of histamine from mast cells and basophils
angioedema, itching, conjunctivitis, rhinitis, bronchospasm, GI cramps
allergic rhinitis
s/s
when allergies occur year round, otherwise called hay fever
conjunctivitis, rhinitis
Type II hypersensitivity
How does it happen? Mediated by? Examples?
tissue specific, cytotoxic mediated
- specific cell or tissue is the target of an immune response
- mediated by IgG and IgM
Five mechanisms by which this occurs but one way is by antibody-dependent cell-mediated cytotoxicity
Examples: Graves disease, autoimmune hemolytic anemia, rheumatic fever
Type II hypersensitivity that occurs 1wk to 6mo. after group A beta hemolytic streptococcal pharyngitis
s/s
Rheumatic fever
fever, migratory polyarthritis, carditis –> causes rheumatic heart disease (chronic)
Type III hypersensitivity
immune (antigen-antibody) complex mediated
- complexes are formed in the circulation and later deposited in vessel walls or extravascular tissues
- IS NOT ORGAN SPECIFIC
Intermediate size complexes are the ones that are not cleared and get deposited in tissues
Type III hypersensitivity has periods of remission and exacerbation…what are some examples?
serum sickness - affects blood vessels, joints, and kidney; Raynaud phenomenon
arthus reaction - deposit in walls of local blood vessels (causes vascular permeability, edema, clotting, etc.)
SLE
Type IV - mediated by? destruction by?
Examples?
MS, skin test for TB, contact allergic reactions, DM 1, Hashimoto disease, Crohn’s disease
Which of the hypersensitivities involves allergies?
all of them
Type I allergens
pollen, molds, fungi foods animals certain drugs cig smoke, house dust
Type II and III allergens
allergens are RARE in these, but can include abx like PCN, and antigens produced by Hep B
Type IV allergens
plant resins, metals, acetylates; chemicals in rubber, cosmetics, detergents, and topical abx
1 control of allergy is through
ANS - biochemical mediators (epi, acetylcholine) bind to appropriate receptors on mast cells and target cells of inflammation
antigenic targets of type IV hypersensitivity reactions
Type IV: mostly haptens that react with normal self-proteins in the skin
result: allergic contact dermatitis (Poison Ivy)
antigenic targets for type II and III
examples?
haptens that bind to the surface of cells and elicit an IgG or IgM response
drug allergy - type II
arthus reaction - type III
SLE what type of hypersensitivity?
autoantibodies against?
type III
autoantibodies against: nucleic acids, RBCs, coagulation proteins, phospholipids, lymphocytes, platelets, and many others
*deposition of circulating immune complexes containing antibody against the host’s DNA
Clinical manifestations of SLE
joint pains, vasculitis and rash, renal disease, hematologic changes (anemia), cardiovascular disease
Eleven findings present in SLE, 4 = dx
presence of what antibodies?
malar rash (face), discoid rash, photosensitivity, mouth ulcers, nonerosive arthritis, serositis, renal disorders, neuro disorders, hematologic disorders, immunologic disorders, and…
presence of antinuclear antibodies (ANAs)
what type of hypersensitivity is a transfusion reaction
alloimmune type II hypersensitivity rxn (specific target - RBCs)
Universal donor
O- blood type (no antigens on surface) anti-A and anti-b antibodies
Universal recipient
AB+ (surface antigens A+B) and no antibodies
Rh-positive
expresses the D antigen on the RhD protein
hemolytic disease of the newborn
Rh- negative mother gives birth to a Rh+ infant
*Rh- individual makes anti-D antibodies if exposed to Rh+ RBCs
Graft rejection (alloimmune rxn) - 3 types
hyperacute - rare d/t pre-existing antibodies
acute - cell-mediated against unmatched HLA antigens
chronic - months to years; d/t weak cell-mediated response reaction against minor antigens
primary immune deficiency is….
secondary immune deficiency is…
hallmark of immune deficiency?
primary is genetic (congenital)
secondary is acquired (caused by illness)
recurrent infections
recurrent gonorrhea suggests what deficiency
complement deficiency
recurrent viral infections suggests what deficiency
t-cell
recurrent microorganism requiring opsonization infection suggests
deficiency in B-cell and phagocytes
causes of secondary immune deficiencies (acquired)
stress, diet insufficient, malignancies, met disease, trauma, treatments, infections (AIDS)
erythema infectiosum (fifth disease)
infection by which virus?
parvovirus B19
droplet
up to 21 day incubation
slapped cheek syndrome
mild self-limiting viral disease - red macular rash first appearing on cheeks and ears
-low grade fever, h/a, rash, cold-like symptoms
Hepangina caused by? s/s? transmitted how?
acute viral illness caused by enterovirus coxsackie A and B
s/s: fever, ulcerative mouth lesions, cough, coryza, pharyngitis, high fever (up to 106), sore throat, n/v/d, fatigue, etc.
tonsilor lesions - culture to r/o strep
fecal-oral and oral-oral
Mono - transmitted how? Incubation? Screening?
EBV
Transmission oropharyngeal route (saliva) or blood
incubation 30-50 days
monospot screening (check for antibody) and consider EBV antibody titer (esp in older pt)
influenza caused by? can undergo?
orthomyxovirus (ssRNA virus) that appears in Antigenic types A and B
antigenic drift or mutation: change in surface molecules
antigenic shift - recombination into a new virus from two different species
Measles also called? caused by? s/s? transmitted how? dx?
Rubeola
RNA virus, paramyxovirus family
s/s: fever, red maculopapular rash, cough, coryza, conjunctivitis, characteristic rash or oral mucus membranes (Koplik spots)
transmitted by direct contact with infectious droplets, or less commonly by airborne spread (highly contagious)
dx: detected from nasopharyngeal secretions, conjunctiva, blood, urine
Mumps (parotitis)
paramyxovirus or mumps virus
symptoms: tender swollen parotid glands for 7-10 days, fever
virus best collected in saliva
rubella (german measles)
mild viral disease also known as 3-day measles
transmitted by direct or droplet contact with nasopharyngeal secretions
rubella virus (RNA, togaviridae fam)
s/s: maculopapular rash beginning on face and spreading to trunk that resolves by day 3
virus detected by nasal smear
*infants w/congenital rubella may shed virus for 1 yr or more
varicella - also called? how is it spread? what virus? dx tests?
chickenpox
usually mild acute viral disease, highly contagious
caused by varicella zoster virus (herpes family)
airborne, touch (rarely)
can be contacted by someone who has shingles (herpes zoster)
no dx tests indicated
west nile virus? s/s? how contracted? caused by what virus? dx
febrile, rash, arthritis, myalgia, weak, lymphadenopathy, meningoencephalitis, n/v, rash, h/a
caused by arbovirus family Flaviviridae
transmission: mos to bird, bird to mos to human
CSF with IgM antibody; pleocytosis: increased number of lymphocytes in CSF
cytomegalovirus, transmitted how? s/s? remains in person? most common what?
DNA virus; herpesvirus
direct contact
immunocompromised at risk - think transplant
most common congenital infection in the US at delivery (5-15% of all newborns)
remains with person for life
symptoms: mono-like w/fever, fatigue, pharyngitis, ulcerative lesions in mouth; loss of vision
retinitis
