Type III hypersensitivity - wikipedia Type III hypersensitivity Type III hypersensitivity Immune complex Classification and external resources MeSH D007105 ( edit on Wikidata ) Type III hypersensitivity occurs when there is accumulation of immune complexes ( antigen - antibody complexes ) that have not been adequately cleared by innate immune cells, giving rise to an inflammatory response and attraction of leukocytes. Such reactions progressing to the point of disease produce immune complex diseases. Contents 1 Signs and symptoms 2 Examples 3 See also 4 References Signs and symptoms Play media Video explanation of type III hypersensitivity Type III hypersensitivity occurs when there is an excess of antigen, leading to small immune complexes being formed that fix complement and are not cleared from the circulation. It involves soluble antigens that are not bound to cell surfaces ( as opposed to those in type II hypersensitivity ). When these antigens bind antibodies, immune complexes of different sizes form. Large complexes can be cleared by macrophages but macrophages have difficulty in the disposal of small immune complexes. These immune complexes insert themselves into small blood vessels, joints, and glomeruli, causing symptoms. Unlike the free variant, a small immune complex bound to sites of deposition ( like blood vessel walls ) are far more capable of interacting with complement ; these medium - sized complexes, formed in the slight excess of antigen, are viewed as being highly pathogenic. Such depositions in tissues often induce an inflammatory response, and can cause damage wherever they precipitate. The cause of damage is as a result of the action of cleaved complement anaphylotoxins C3a and C5a, which, respectively, mediate the induction of granule release from mast cells ( from which histamine can cause urticaria ), and recruitment of inflammatory cells into the tissue ( mainly those with lysosomal action, leading to tissue damage through frustrated phagocytosis by PMNs and macrophages ). Immune Complex Glomerulonephritis, as seen in Henoch - Schönlein purpura ; this is an example of IgA involvement in a nephropathy The reaction can take hours, days, or even weeks to develop, depending on whether or not there is immunological memory of the precipitating antigen. Typically, clinical features emerge a week following initial antigen challenge, when the deposited immune complexes can precipitate an inflammatory response. Because of the nature of the antibody aggregation, tissues that are associated with blood filtration at considerable osmotic and hydrostatic gradient ( e.g. sites of urinary and synovial fluid formation, kidney glomeruli and joint tissues respectively ) bear the brunt of the damage. Hence, vasculitis, glomerulonephritis and arthritis are commonly associated conditions as a result of type III hypersensitivity responses. As observed under methods of histopathology, acute necrotizing vasculitis within the affected tissues is observed concomitant to neutrophilic infiltration, along with notable eosinophilic deposition ( fibrinoid necrosis ). Often, immunofluorescence microscopy can be used to visualize the immune complexes. Skin response to a hypersensitivity of this type is referred to as an Arthus reaction, and is characterized by local erythema and some induration. Platelet aggregation, especially in microvasculature, can cause localized clot formation, leading to blotchy hemorrhages. This typifies the response to injection of foreign antigen sufficient to lead to the condition of serum sickness. Examples Some clinical examples : Disease Target antigen Main effects Systemic lupus erythematosus Nuclear antigens Nephritis Skin lesions Arthritis Rheumatoid Arthritis Antibody complexes : specifically IgM to IgG Arthritis Post-streptococcal glomerulonephritis Streptococcal cell wall antigens Nephritis Polyarteritis nodosa Hepatitis B virus surface antigen Systemic vasculitis Reactive arthritis Several bacterial antigens Acute arthritis Serum sickness Various Arthritis Vasculitis Nephritis Arthus reaction Various Cutaneous vasculitis Farmer 's Lung Inhaled antigens ( often mould or hay dust ) Alveolar inflammation Henoch -- Schönlein purpura Unknown, likely respiratory pathogen Purpura Glomerulonephritis Unless else specified in boxes, then ref is : Other examples are : Subacute bacterial endocarditis Symptoms of malaria See also Type I hypersensitivity Type II hypersensitivity Type IV hypersensitivity Type V hypersensitivity References Jump up ^ `` Hypersensitivity reactions ''. Retrieved 2008 - 09 - 26. Jump up ^ Parham, Peter ( 2009 ). `` 12 ''. The Immune System ( 3rd ed. ). New York, NY : Garland Science. p. 390. Jump up ^ `` Chapter 19 ''. Retrieved 2009 - 01 - 08. ^ Jump up to : Parham, Peter ( 2009 ). `` 12 ''. The Immune System ( 3rd ed. ). New York, NY : Garland Science. p. 389. ^ Jump up to : Kumar, Vinay ( 2010 ). `` 6 ''. Robbins and Cotran Pathologic Mechanisms of Disease ( 8th ed. ). Philadelphia : Elsevier. pp. 204 -- 205. Jump up ^ Table 5 - 3 in : Mitchell, Richard Sheppard ; Kumar, Vinay ; Abbas, Abul K. ; Fausto, Nelson. Robbins Basic Pathology. Philadelphia : Saunders. ISBN 1 - 4160 - 2973 - 7. 8th edition. Jump up ^ `` Definition : immune complex disease from Online Medical Dictionary ''. Hypersensitivity and autoimmune diseases ( 279.5 -- 6 ) Type I / allergy / atopy ( IgE ) Foreign Atopic eczema Allergic urticaria Allergic rhinitis ( Hay fever ) Allergic asthma Anaphylaxis Food allergy common allergies include : Milk Egg Peanut Tree nut Seafood Soy Wheat Penicillin allergy Autoimmune Eosinophilic esophagitis Type II / ADCC IgM IgG Foreign Hemolytic disease of the newborn Autoimmune Cytotoxic Autoimmune hemolytic anemia Immune thrombocytopenic purpura Bullous pemphigoid Pemphigus vulgaris Rheumatic fever Goodpasture 's syndrome Guillain -- Barré syndrome `` Type V '' / receptor Graves ' disease Myasthenia gravis Pernicious anemia Type III ( Immune complex ) Foreign Henoch -- Schönlein purpura Hypersensitivity vasculitis Reactive arthritis Farmer 's lung Post-streptococcal glomerulonephritis Serum sickness Arthus reaction Autoimmune Systemic lupus erythematosus Subacute bacterial endocarditis Rheumatoid arthritis Type IV / cell - mediated ( T cells ) Foreign Allergic contact dermatitis Mantoux test Autoimmune Diabetes mellitus type 1 Hashimoto 's thyroiditis Multiple sclerosis Coeliac disease Giant - cell arteritis Postorgasmic illness syndrome Reactive arthritis GVHD Transfusion - associated graft versus host disease Unknown / multiple Foreign Hypersensitivity pneumonitis Allergic bronchopulmonary aspergillosis Transplant rejection Latex allergy ( I + IV ) Autoimmune Sjögren 's syndrome Autoimmune hepatitis Autoimmune polyendocrine syndrome APS1 APS2 Autoimmune adrenalitis Systemic autoimmune disease Retrieved from `` https://en.wikipedia.org/w/index.php?title=Type_III_hypersensitivity&oldid=809588283 '' Categories : Hypersensitivity Hidden categories : Infobox medical condition Talk Contents About Wikipedia Español Português Edit links This page was last edited on 10 November 2017, at 02 : 47. 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Question: an example of a type iii hypersensitivity is
Answer: vasculitis