Handout -Tables Hypersensitivity Reactions PDF

SUMMARY: HYPERSENSITIVITY REACTIONS Type I Type II Type III Type IV Other Immediate / Antibody-mediated Immune-complex T-cell Media...

SUMMARY: HYPERSENSITIVITY REACTIONS Type I Type II Type III Type IV Other Immediate / Antibody-mediated Immune-complex T-cell Mediated name Ig-E mediated / Allergy hypersensitivity Mediator IgE IgG; IgM IgG; IgM CD4+ (Th1; Th17) CD8+ CTL Mechanism Production of IgE Abs IgG, IgM à binds to Ag on 1. Ag-Ab complex IVa. cytokine- à immediate release target cells or tissue à formation mediated of vasoactive amines IIa. Opsonization & 2. Complex deposition inflammation and mediators from Phagocytosis /. 3. Complement IVb. T cell-mediated mast cells; Antibody-Dependent activation, inflammation cytotoxicity Cellular Cytotoxicity Inflammation IIb. Complement & Fc receptor-mediated inflammation IIc. Antibody-mediated Cellular Dysfunction Examples Atopy; Allergy; AIHA, AITP, Hemolytic SLE Tuberculosis (IVa) Bronchial Asthma; Transfusion Reactions; Serum sickness Response to viral Allergic rhinitis; Erythroblastosis Fetalis (IIa) Arthus reaction infections (IVb) Anaphylaxis Goodpasture syndrome Farmer’s lung Transplant rejection; (IIb) Type I DM; Graves, Myasthenia Gravis Multiple sclerosis (IIc) Reference: Robbin’s & Cotran Pathologic Basis of Disease, 10th ed. Disease Examples of Antibody-mediated (Type II) Hypersensitivity DISEASE TARGET ANTIGEN MECHANISM Autoimmune hemolytic RBC membrane proteins IIa opsonization and anemia phagocytosis of erythrocytes Autoimmune Platelet membrane IIa opsonization & thrombocytopenic proteins phagocytosis purpura of platelets Goodpasture syndrome Noncollagenous protein IIb complement and Fc in BM of alveoli and receptor glomeruli mediated inflammation Myasthenia gravis Acetylcholine receptor IIc Ab inhibits Acetylcholine binding; down regulates receptors Graves disease TSH receptor IIc antibody-mediated (hyperthyroidism) stimulation of TSH receptors Reference: Robbin’s & Cotran Pathologic Basis of Disease, 10th ed. Disease examples of Type III (Immune-Complex Mediated) Hypersensitivity DISEASE ANTIGEN INVOLVED MANIFESTATIONS SLE DNA, nucleoproteins, others Nephritis, arthritis, vasculitis Poststreptococcal Streptococcal cell wall Nephritis glomerulonephritis antigen(s); may be “planted in glomerular basement Acute Bacterial, parasite, tumor Nephritis glomerulonephritis antigens Arthus reaction Various foreign proteins Cutaneous vasculitis Serum sickness Various proteins Arthritis, vasculitis, (eg foreign serum) nephritis Reference: Robbin’s & Cotran Pathologic Basis of Disease, 10th ed. Disease Examples of Type IV (Cell Mediated) Hypersensitivity Type IV (Cell Mediated / Delayed type) Hypersensitivity is the mechanism of the following: Tuberculin (PPD) reaction Granulomatous reaction Transplant rejection Reaction to cancer Disease Specificity of Mechanism Clinicopathologic Pathogenic T cells of Injury Manifestations Rheumatoid Collagen? Cytokine-mediated Chronic arthritis; Arthritis Citrullinated self- inflammation inflammation and proteins? (CD4+Tcells) destruction of articular cartilage Multiple Sclerosis Protein antigens in myelin Cytokine-mediated Demyelination in CNS with (myelin basic protein) inflammation perivascular inflammation; (CD4+Tcells) paralysis Type I DM Antigens of pancreatic T-cell mediated Insulinitis islet B cells destruction by CTLs (chronic inflammation in (insulin, glutamic acid (CD8+T cells) islets); decarboxylase) destruction of B cells; Diabetes Inflammatory Enteric bacteria; Cytokine-mediated Chronic intestinal bowel disease Self-antigens? inflammation inflammation; obstruction (CD4+Tcells) Reference: Robbin’s & Cotran Pathologic Basis of Disease, 10th ed.