Question

What is hypersentivity and explain all four types of hypersensitivity?

Answer 1

Hypersensitivity (also called hypersensitivity reaction or intolerance) is a set of undesirable reactions produced by the normal immune system, including allergiesand autoimmunity. These reactions may be damaging, uncomfortable, or occasionally fatal. Hypersensitivity reactions require a pre-sensitized (immune) state of the host. Comparison of hypersensitivity typesTypeAlternative namesOften mentioned disordersMediatorsDescriptionIAllergy (immediate)AtopyAnaphylaxisAsthmaIgEFast response which occurs in minutes, rather than multiple hours or days. Free antigens cross link the IgE on mast cells and basophils which causes a release of vasoactive biomolecules.Testing can be done via skin test for specific IgE.[2]IICytotoxic, antibody-dependentAutoimmune hemolytic anemiaThrombocytopeniaRheumatic heart diseaseErythroblastosis fetalisGoodpasture's syndromeMembranous nephropathyGraves' disease *see type V explanation belowMyasthenia gravis *see type V explanation belowIgM or IgG(Complement)MACAntibody (IgM or IgG) binds to antigen on a target cell, which is actually a host cell that is perceived by the immune system as foreign, leading to cellular destruction via the MAC.Testing includes both the direct and indirect Coombs test.[3]IIIImmune complex diseaseSerum sicknessArthus reactionRheumatoid arthritisPost streptococcal glomerulonephritisLupus nephritisSystemic lupus erythematosusExtrinsic allergic alveolitis(hypersensitivity pneumonitis)IgG(Complement)NeutrophilsAntibody (IgG) binds to soluble antigen, forming a circulating immune complex. This is often deposited in the vessel walls of the joints and kidney, initiating a local inflammatory reaction.[4]IVDelayed-type hypersensitivity,[2][3] cell-mediated immune memory response, antibody-independentContact dermatitisMantoux testChronic transplant rejectionMultiple sclerosis[5]T-cellsT cells find antigen and activate macrophages.[6]VAutoimmune disease, receptor mediated (see below)Graves' diseaseMyasthenia gravisIgM or IgG(Complement)

Answer 2

Hypersensitivity and its types

Explanation:-

Hypersensitivity (also referred to as hypersensitivity or intolerance) refers to undesirable reactions made by the traditional system, as well as allergies and pathology. they're typically observed as associate degree over-reaction of the system and these reactions are also damaging, uncomfortable, or often fatal. Hypersensitivity reactions need a pre-sensitized (immune) state of the host. The Gell and Coombs classification of hypersensitivity is that the most generally used, and distinguishes four varieties of immune reaction that end in spectator tissue injury.

Type of hypersensitivity reaction is:-

1. Type I: reaction mediated by immune gamma globulin antibodies
2. Type II: cytotoxic reaction mediate by immunoglobulin or immunoglobulin antibodies
3. Type III: reaction mediated by immune complexes
4. Type IV: delayed reaction mediate by cellular response