Hypersensitivity: Difference between revisions

Hypersensitivity
Hypersensitivity
Specialty	Emergency medicine, immunology

Browse history interactively

← Previous edit Next edit →

Content deleted Content added

VisualWikitext

Inline

Revision as of 16:59, 18 September 2013

Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to ASKudgEWFVHEIFGQBFHIYundesirable reactions produced by the normal immune system, including allergies and autoimmunity. These reactions may be damaging, uncomfortable, or occasionally fatal. Hypersensitivity reactions require a pre-sensitized (immune) state of the host. The four-group classification was expounded by P. H. G. Gell and Robin Coombs in 1963.^[1]

Coombs and Gell classification

**Comparison of hypersensitivity types**
Type	Alternative names	Often mentioned disorders	Mediators
I	Allergy (immediate)	Atopy Anaphylaxis Asthma	IgE and IgG4
II	Cytotoxic, antibody-dependent	Autoimmune hemolytic anemia Thrombocytopenia Erythroblastosis fetalis Goodpasture's syndrome Membranous nephropathy Graves' disease see type V explanation below Myasthenia Gravis see type V explanation below	IgM or IgG (Complement)
III	Immune complex disease	Serum sickness Arthus reaction Rheumatoid arthritis Post streptococcal glomerulonephritis Lupus Nephritis Systemic lupus erythematosus (SLE) Extrinsic allergic alveolitis (Hypersensitivity pneumonitis)	IgG (Complement)
IV	Delayed-type hypersensitivity^[2]^[3](DTH), cell-mediated immune memory response, antibody-independent	Contact dermatitis Mantoux test Metal joint replacement Chronic transplant rejection Multiple sclerosis ^[4]	T-cells
V	Autoimmune disease, receptor mediated (see below)	Graves' disease Myasthenia Gravis	IgM or IgG (Complement)

Type V

This is an additional type that is sometimes (often in the UK) used as a distinction from Type 2.^[5]

Instead of binding to cell surface components, the antibodies recognise and bind to the cell surface receptors, which either prevents the intended ligand binding with the receptor or mimics the effects of the ligand, thus impairing cell signaling.

Some clinical examples:

The use of Type 5 is rare. These conditions are more frequently classified as Type 2, though sometimes they are specifically segregated into their own subcategory of Type 2.

References

^ Gell PGH, Coombs RRA, eds. Clinical Aspects of Immunology. 1st ed. Oxford, England: Blackwell; 1963.
^ Black, CA. Delayed Type Hypersensitivity: Current Theories with an Historic Perspective Dermatol. Online J. (May 1999) 5(1):7 at http://dermatology.cdlib.org/DOJvol5num1/reviews/black.html
^ http://emedicine.medscape.com/article/136118-overview
^ Table 5-1 in:Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson (2007). Robbins Basic Pathology. Philadelphia: Saunders. ISBN 1-4160-2973-7.{{cite book}}: CS1 maint: multiple names: authors list (link) 8th edition.
^ Rajan TV (2003). "The Gell-Coombs classification of hypersensitivity reactions: a re-interpretation". Trends Immunol. 24 (7): 376–9. doi:10.1016/S1471-4906(03)00142-X. PMID 12860528. {{cite journal}}: Unknown parameter |month= ignored (help)

External links

"Hypersensitivity reactions". GPnotebook.

Template:Medical conditions

[1] Gell PGH, Coombs RRA, eds. Clinical Aspects of Immunology. 1st ed. Oxford, England: Blackwell; 1963.

[2] Black, CA. Delayed Type Hypersensitivity: Current Theories with an Historic Perspective Dermatol. Online J. (May 1999) 5(1):7 at http://dermatology.cdlib.org/DOJvol5num1/reviews/black.html

[3] ttp://emedicine.medscape.com/article/136118-overview

[Kumar5-1-4] Table 5-1 in:Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson (2007). Robbins Basic Pathology. Philadelphia: Saunders. ISBN 1-4160-2973-7.{{cite book}}: CS1 maint: multiple names: authors list (link) 8th edition.

[pmid12860528-5] Rajan TV (2003). "The Gell-Coombs classification of hypersensitivity reactions: a re-interpretation". Trends Immunol. 24 (7): 376–9. doi:10.1016/S1471-4906(03)00142-X. PMID 12860528. {{cite journal}}: Unknown parameter |month= ignored (help)

[1]

[2]

[3]

[4]

[5]

@@ Line 17: / Line 17: @@
   MeshID         = D006967 |
 }}
-'''Hypersensitivity''' (also called '''hypersensitivity reaction''' or '''intolerance''') refers to undesirable reactions produced by the normal immune system, including [[allergies]] and [[autoimmunity]]. These reactions may be damaging, uncomfortable, or occasionally fatal.  Hypersensitivity reactions require a pre-sensitized (immune) state of the host. The four-group classification was expounded by [[Philip George Houthem Gell|P. H. G. Gell]] and [[Robin Coombs]] in 1963.<ref>Gell PGH, Coombs RRA, eds. Clinical Aspects of Immunology. 1st ed. Oxford, England: Blackwell; 1963.</ref>
+'''Hypersensitivity''' (also called '''hypersensitivity reaction''' or '''intolerance''') refers to ASKudgEWFVHEIFGQBFHIYundesirable reactions produced by the normal immune system, including [[allergies]] and [[autoimmunity]]. These reactions may be damaging, uncomfortable, or occasionally fatal.  Hypersensitivity reactions require a pre-sensitized (immune) state of the host. The four-group classification was expounded by [[Philip George Houthem Gell|P. H. G. Gell]] and [[Robin Coombs]] in 1963.<ref>Gell PGH, Coombs RRA, eds. Clinical Aspects of Immunology. 1st ed. Oxford, England: Blackwell; 1963.</ref>
 ==Coombs and Gell  classification==