Immunology - Hypersensitivity

eesohbel's version from 2015-07-18 00:37

Hypersensitivity Types

Question Answer
All 4 typesACID
Type 1: anaphylactic and atopic
Type 2: Cytotoxic
Type 3: Immune complex
Type 4: Delayed (T-cell-mediated) type
Which type does not involve antibodies?Type 4
Examples of Type 4T's
Transplant rejections
TB skin tests
Touching (contact dermatitis)
Serum sickness mechanismImmune complex disease (type 3)
Antibodies to foreign proteins are produced (takes 5 days)
Immune complexes form & deposited in membranes
Arthus reactionlocal subacute antibody-mediated hypersensitivity (type 3)
Intradermal injection of antigen → induces antibodies → form antigen-antibody complex in the skin
Edema, necrosis, and activation of complement
Test for Type 1skin test specific for IgE
Test for Type 2direct or indirect Coombs'
Example of Type 2penicillin binds to RBCs → Recognized by body as foreign → B cells proliferate producing IgM and IgG that take out the cell (RBC in this case)
Serum sickness presentationFever, urticaria, arthralgias, proteinuria, lymphadenopathy
5-10 days after antigen exposure
Test for Type 3Immunofluorescent staining
Test for Type 4Patch test, PPD
Type 1 presentationImmediate, anaphylactic, atopic (may occur in part of the body that's not in contact with the allergen)
Type 2 presentationDisease tends to be specific to tissue or site where antigen is found
Type 3 presentationCan be associated with vasculitis and systemic manifestations
Type 4 presentationResponse is delayed and does not involve antibodies

Rapid-fire Hypersensitivity disorders

Question Answer
Anaphylaxis (bee sting, some food/drug allergies)Type 1
Allergic and atopic disorders (rhinitis, hay fever, eczema, hives, asthma)Type 1
Autoimmune hemolytic anemiaType 2
Pernicious anemiaType 2
Idiopathic thrombocytopenic purpuraType 2
Erythroblastosis fetalisType 2
Rheumatic feverType 2
Goodpasture's syndromeType 2
Bullous pemphigoidType 2
Pemphigus vulgarisType 2
SLEType 3
Polyarteritis nodosaType 3
Poststreptococcal glomerulonephritisType 3
Serum sicknessType 3
Arthus reaction (swelling & inflammation following a vaccine)Type 3
Multiple sclerosisType 4
Guillain-Barre syndromeType 2
Graft-versus-host diseaseType 4
PPDType 4
Contact dermatitisType 4
Poison IvyType 4
MStype 4

Blood Transfusions

TypePathogenesisClinical Presentation
allergic reactiontype I hypersensitivity against plasma proteinsuriticaria, pruritis, wheezing, fever. Treat w/antihistamines
anaphylaticIgA deficient patients recieive blood with IgA type 1shock. treat w epi
febirle nonhemolytictype II hypersensitivityfever, headaches
acute hemolytictype II. ABO incompatibilityhemoglobinuria (intravascular hemolysis) and jaundice (extravascular hemolysis)

Rapid-fire autoantibodies

Question Answer
ANASLE, nonspecific
Anti-dsDNA, anti-SmithSLE
AntihistoneDrug-induced lupus
Rheumatoid factorRheumatoid arthritis
anti-CCPRheumatoid arthritis
AnticentromereScleroderma (CREST syndrome)
Anti-Scl-70 (anti-DNA topoisomerase I)Scleroderma (diffuse)
Antimitochondrial1° biliary cirrhosis
IgA antiendomysial, IgA anti-tissue transglutaminaseCeliac disease
Anti-basement membraneGoodpasture's syndrome
Anti-desmogleinpemphigus vulgaris
AntimicrosomalHashimoto's thyroiditis
antithyroglobulinHashimoto's thyroiditis or Graves
Anti-Jo-1, anti-SRP, anti-Mi-2Polymyositis, dermatomyositis
Anti-SSA (anti-Ro)Sjogren's syndrome
Anti-SSB (anti-La)Sjogren's syndrome
Anti-U1 RNP (ribonucleoprotein)Mixed connective tissue disease
Anti-smooth muscleAutoimmune hepatitis
Anti-glutamate decarboxylaseType 1 DM
c-ANCA (PR3-ANCA)Granulomatosis with polyangiitis (Wegener's)
p-ANCA (MPA-ANCA)Microscopic polyangiitis, Churg-Strauss syndrome
anti-smooth muscleauto-immune hepatitis


Question Answer
Autograftfrom self
Syngeneic graftFrom identical twin or clone
AllograftFrom another person
Xenograftfrom different species
Hyperacute rejectionsminutes to hours. preformed antibodies against graft. type 2 hypersensitivity gross mottling and cyanosis.
Acute rejectionWeeks later
Vasculitis of graft vessels with dense interstitial lymphocytic infiltrates
Cell mediated due to cytotoxic T cells reacting against foreign MHCS
Chronic rejectionObliterative vascular fibrosis - months to years later
Class I-MHCnon-self perceived by CTLs as class I-MHCself presenting a non-self antigen
Graft-versus-host rejectionMaculopapular rash, jaundice, hepatosplenomegaly, diarrhea
Usually bone marrow and liver transplant
Irradiated, immunocompromised host
Donor immunocompetent T cells spread in the irradiated immunocompromised host, and reject host cells
graft versus tumor effectGVHD may be potentially beneficial in bone marrow transplant for leukemia