Difference between revisions of "Type II Hypersensitivity"

From WikiVet English
Jump to navigation Jump to search
(30 intermediate revisions by 6 users not shown)
Line 1: Line 1:
 +
{{toplink
 +
|backcolour = FFE4E1
 +
|linkpage =Immunology - WikiBlood
 +
|linktext =IMMUNOLOGY
 +
|sublink1 =Hypersensitivity - WikiBlood
 +
|subtext1 =HYPERSENSITIVITY
 +
|pagetype =Blood
 +
}}
 +
 +
 +
[[Image:Type II Hypersensitivity.jpg|right|thumb|150px|Type II Hypersensitivity-Brian Catchpole RVC 2008]]
 
==Introduction==
 
==Introduction==
[[Image:Type II Hypersensitivity.jpg|right|thumb|150px|Type II Hypersensitivity-Brian Catchpole RVC 2008]]
+
 
Production of [[Immunoglobulin M|IgM]] or [[Immunoglobulin G|IgG]] to cell surface antigens or extracellular matrix proteins.
+
Production of IgM or IgG to cell surface antigens or extracellular matrix proteins.
  
 
==Mechanism==
 
==Mechanism==
 +
  
 
''' "Neutralisation" blockade of receptors:'''
 
''' "Neutralisation" blockade of receptors:'''
* Antibodies attach to receptors, which prevents other molecules attaching.  
+
* Antibodies attach to receptors which prevents other molecules attaching.  
 
* For example in myasthenia gravis antibodies attach to acetylcholine receptors which in turn prevents acetylcholine from attaching to the receptor and thus muscle contraction of that cell does not occur.  
 
* For example in myasthenia gravis antibodies attach to acetylcholine receptors which in turn prevents acetylcholine from attaching to the receptor and thus muscle contraction of that cell does not occur.  
 +
  
 
''' Immunological attack on target cells, destroying them by (see diagram):'''
 
''' Immunological attack on target cells, destroying them by (see diagram):'''
  
[[Adaptive Immunity to Viruses|1. Antibody dependent cell cytotoxicity (ADCC)]]
+
1. Antibody dependent cell cytotoxicity (ADCC)
* [[Pemphigus|Pemphigus vulgaris]]
+
* Pemphigus vulgaris
* [[Bullous Pemphigoid|Bullous pemphigoid]]
+
* Bullous pemphigoid
  
2. [[Complement|Complement]] mediated lysis
+
2. Complement mediated lysis
* Self [[Erythrocytes|RBC]] antigen:
+
* Self RBC antigen:
** [[Immune Mediated Haemolytic Anaemia|Immune mediated haemolytic anaemia]]
+
** Immune mediated haemolytic anaemia
* Foreign [[Erythrocytes|RBC]]:
+
* Foreign RBC:
 
** Blood transfusion reaction
 
** Blood transfusion reaction
** [[Neonatal Isoerythrolysis|Haemolytic disease of new born (Rhesus disease in humans and neonatal isoerythrolysis in foals and kittens)]]
+
** Haemolytic disease of new born (Rhesus disease in humans and neonatal isoerythrolysis in foals and kittens)
 
* RBC parasite:
 
* RBC parasite:
 
** Feline infectious anaemia (''Mycoplasma haemofelis'')  
 
** Feline infectious anaemia (''Mycoplasma haemofelis'')  
 
3. Phagocytosis
 
3. Phagocytosis
 
==From Pathology==
 
 
*Cytotoxic reaction
 
*[[IgG]] and [[IgM]] interaction with antigens bound to cellular membranes
 
*Often involves [[Complement#Complement Fixation Pathways|complement fixation]] -> cellular damage
 
*In skin - circulating antibody to proteins of desmosomes in intercellular areas along basement membranes at epidermal-dermal junction
 
*Includes:
 
**[[Pemphigus|Pemphigus]]
 
**[[Bullous Pemphigoid|Bullous pemphigoid]]
 
 
 
<br><br>
 
{{Jim Bee 2007}}
 
[[Category:Hypersensitivity]]
 

Revision as of 15:38, 29 August 2008

WikiBloodWikiBlood Banner.png
IMMUNOLOGY
HYPERSENSITIVITY



Type II Hypersensitivity-Brian Catchpole RVC 2008

Introduction

Production of IgM or IgG to cell surface antigens or extracellular matrix proteins.

Mechanism

"Neutralisation" blockade of receptors:

  • Antibodies attach to receptors which prevents other molecules attaching.
  • For example in myasthenia gravis antibodies attach to acetylcholine receptors which in turn prevents acetylcholine from attaching to the receptor and thus muscle contraction of that cell does not occur.


Immunological attack on target cells, destroying them by (see diagram):

1. Antibody dependent cell cytotoxicity (ADCC)

  • Pemphigus vulgaris
  • Bullous pemphigoid

2. Complement mediated lysis

  • Self RBC antigen:
    • Immune mediated haemolytic anaemia
  • Foreign RBC:
    • Blood transfusion reaction
    • Haemolytic disease of new born (Rhesus disease in humans and neonatal isoerythrolysis in foals and kittens)
  • RBC parasite:
    • Feline infectious anaemia (Mycoplasma haemofelis)

3. Phagocytosis