Hipersensibilidade Tipo III - Doenças Mediadas por Imunocomplexos

ImunoCanal
17 Mar 202223:00

Summary

TLDRIn this class, Rony explains type 3 hypersensitivity, which is mediated by immune complexes that can cause systemic diseases. He covers key concepts such as serum sickness, immune complex deposition in organs like the kidneys and joints, and the resultant inflammation leading to diseases like glomerulonephritis, vasculitis, and arthritis. The class explores experimental models, including serum sickness and Arthus reaction, to demonstrate immune complex formation and its pathological effects. Rony also delves into autoimmune diseases, such as lupus, highlighting how immune complexes contribute to tissue damage. The lecture concludes with real-life examples of conditions driven by type 3 hypersensitivity.

Takeaways

  • 😀 Type 3 hypersensitivity is mediated by immune complexes and affects various organs such as kidneys, joints, and small arteries.
  • 😀 Serum sickness is an example of type 3 hypersensitivity, caused by the formation of immune complexes after receiving serum from immunized animals.
  • 😀 Immune complexes can form when antibodies bind to antigens, leading to pathological conditions like vasculitis, nephritis, and arthritis.
  • 😀 Diseases mediated by immune complexes are often systemic and can cause inflammation in organs such as the skin, kidneys, and joints.
  • 😀 Experimental models, like serum sickness and the Arthus reaction, help us study diseases caused by immune complexes.
  • 😀 The deposition of immune complexes in small arteries, renal glomeruli, and synovium can lead to inflammation and tissue damage.
  • 😀 Autoantibodies, such as those found in systemic lupus erythematosus (SLE), play a significant role in the formation of immune complexes.
  • 😀 In lupus, immune complexes are often formed against nuclear components, leading to diseases like lupus nephritis and skin lesions.
  • 😀 Type 3 hypersensitivity diseases can be associated with infections like hepatitis B and post-streptococcal glomerulonephritis.
  • 😀 Treatment for immune complex-mediated diseases often focuses on managing inflammation and preventing further tissue damage.

Q & A

  • What is the main focus of today's class?

    -The class focuses on type 3 hypersensitivity, which is mediated by immune complexes.

  • What causes type 1 hypersensitivity?

    -Type 1 hypersensitivity is caused by allergies and is mediated by IgE, leading to mast cell degranulation.

  • How does type 2 hypersensitivity work?

    -Type 2 hypersensitivity is mediated by antibodies like IgG and IgM, which can cause opsonization, phagocytosis, and activation of the classical pathway, leading to tissue damage.

  • What are immune complexes and how do they contribute to type 3 hypersensitivity?

    -Immune complexes are formed when antibodies bind to antigens, and they can deposit in tissues like small arteries, glomeruli in kidneys, and synovium of joints, causing inflammation and damage.

  • What is serum sickness, and how was it discovered?

    -Serum sickness is a systemic vasculitis caused by immune complexes formed when patients receive serum from immunized horses. It was discovered in 1911 by Clements after observing symptoms like arthritis and skin rashes in patients receiving the serum.

  • Why can immune complexes cause disease?

    -Immune complexes cause disease because they can be deposited in various organs, leading to inflammation, tissue damage, and disease manifestations like vasculitis, nephritis, and arthritis.

  • What happens in the body when immune complexes are deposited in the kidneys?

    -When immune complexes are deposited in the glomeruli of the kidneys, they cause inflammation, leading to glomerulonephritis and potential kidney damage.

  • How does the Arthur's reaction differ from serum sickness?

    -The Arthur's reaction is a localized form of vasculitis mediated by immune complexes, typically occurring when an animal, already immunized, is injected with the same antigen again, leading to inflammation and tissue necrosis at the injection site.

  • What role do neutrophils play in immune complex-mediated diseases?

    -Neutrophils are attracted to the immune complexes and, upon binding to the antibody region of the complexes, release granules that cause damage to the affected tissue, contributing to conditions like vasculitis.

  • How does systemic lupus erythematosus (SLE) relate to immune complexes?

    -In SLE, autoantibodies are formed against nuclear antigens like DNA and RNA. These autoantibodies bind to the nuclear components, forming immune complexes that deposit in tissues such as the skin, kidneys, and blood vessels, leading to inflammation and symptoms like lupus nephritis and butterfly-shaped rashes.

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Related Tags
ImmunologyType 3 HypersensitivityImmune ComplexesLupusVasculitisSystemic DiseasesExperimental ModelsSerum SicknessKidney DiseaseAutoimmune DisordersMedical Education