Difference between revisions of "Immunodeficiencies - WikiBlood"

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#REDIRECT[[:Category:Immunodeficiencies]]
 
 
{{toplink
 
|linkpage =Immunology - WikiBlood
 
|linktext =IMMUNOLOGY
 
|thispagemap= Immunodeficiencies(Concept Map) - WikiBlood
 
|pagetype =Blood
 
}}
 
 
 
==Introduction==
 
[[Image:Immunodeficiencies Map.jpg|thumb|right|150px|Immunodeficiency Diagram - Copyright nabrown RVC]]
 
Like any system in the body the immune system can go wrong. [[Autoimmune diseases - WikiClinical|Autoimmunity]] is when the immune system begins to attack itself. Immunodeficiency is when the immune system fails to protect itself from disease.
 
 
 
If the immunodeficient defect is present at birth and is therefore a result of a genetic or developmental abnormality, it is called a primary immunodeficiency.
 
 
 
Secondary immunodeficiency, sometimes called acquired immunodeficiency, is the loss of immune function during life, caused by exposure to harmful agents.
 
 
 
Immunodeficiencies can be treated by the replacement of the defective or missing protein, cells or gene. However, in veterinary medicine, [[Vaccines - WikiBlood|vaccinations]] and drugs are the most common treatments for immunodeficiency.
 
 
 
==Primary Immunodeficiency==
 
 
 
*Primary immunodeficiencies may affect either the [[Innate Immune System - WikiBlood|innate immune system]] or the [[Adaptive Immune System - WikiBlood|adaptive immune system]]
 
*They are categorised by either the type or the developmental stage of the cells involved
 
*Lymphoid cell disorders affect [[Lymphocytes - WikiBlood#T cells|T cells]] or [[Lymphocytes - WikiBlood#B cells|B cells]] (or both)
 
*Myeloid cell disorders affect phagocytic function
 
*The severity of the immunodeficiency depends on at which stage in development the problem occurs
 
**E.g. Defects early on in development will affect the entire immune system
 
*[[Lymphocytes - WikiBlood#T cells|T cell]] deficiencies can affect both the cell-mediated and humoral response as [[Lymphocytes - WikiBlood#T cells|T cells]] play a central role in the immune system
 
 
 
===Deficiencies of Innate Immunity===
 
[[Image:Grey Collie Syndrome.jpg|thumb|right|150px|Appearance of a puppy with Grey Collie syndrome - Copyright Michelle Tennis & Peggy Melton]]
 
====Canine Cyclic Haematopoiesis====
 
*Also called '''Grey Collie Syndrome'''
 
*Autosomal recessive
 
*Insertion mutation in AP3B1 gene
 
*Diluted grey coat colour, stunted growth, poor wound healing
 
*Neutropenia every 2 weeks which lasts 3-4 days due to cyclic production of cells from [[Bone Marrow - Anatomy & Physiology|bone marrow]]
 
*Animals are prone to recurrent infections, mainly from the respiratory and gastrointestinal tract
 
**E.g. pyrexia, [[Intestine Diarrhoea - Pathology|diarrhoea]], gingivitis and arthritis
 
*Puppies can be distinguished from other litter mates by the diluted grey colouring
 
*Affected puppies show symptoms such as fever, joint pain and eye, skin and respiratory infections from 8 weeks of age
 
*Affected animals rarely live beyond 2-3 years with most puppies dying within a few weeks of birth
 
 
 
====Canine Leukocyte Adhesion Deficiency (CLAD)====
 
*Occurs in Irish Setters
 
*Missence mutation of -Cys-36-Ser- in CD18 molecule
 
**CD18 is required for [[Neutrophils - WikiBlood|neutrophil]] migration and phagocytosis
 
*Recurrent bacterial infection
 
*Neutrophilia ([[Neutrophils - WikiBlood|neutrophils]] remain in the blood and are unable to fight infection in the tissue)
 
 
 
====Bovine Leukocyte Adhesion Deficiency (BLAD)====
 
*Occurs in Holstein cattle
 
*Missence mutation of -Asp-128-Gly in CD18 molecule
 
*Recurrent infection, e.g. pneumonia
 
 
 
===Deficiencies of Adaptive Immunity===
 
 
 
====Equine Severe Combined Immune Deficiency (Equine SCID)====
 
*Autosomal recessive
 
*Occurs in 2-3% of Arabian foals
 
*Defect in DNA-dependent protein kinase gene
 
**Gene codes for a DNA repair enzyme involved in V(D)J recombination for antigen receptors of [[Lymphocytes - WikiBlood|lymphocytes]] (e.g. Ig and TCR)
 
*No functional [[Lymphocytes - WikiBlood#B cells|B cells]] or [[Lymphocytes - WikiBlood#T cells|T cells]]
 
*Foals develop infections (usually around 8 weeks of age as maternal [[Immunoglobulins - WikiBlood|antibody]] in [[Materno-fetal immunity - WikiBlood#Passive transfer via colostrum|colostrum]] wanes around this time)
 
*Foals usually die from bronchopneumonia
 
 
 
====Canine X-Linked Severe Combined Immune Deficiency (Canine SCID)====
 
*Affects Basset Hounds and Corgis
 
*X-linked recessive defect in the gene coding for the IL-2 receptor
 
**IL-2 receptor is a receptor for the cytokine IL-2 which causes [[Lymphocytes - WikiBlood#T cells|T cells]] to proliferate
 
*Causes lymphoid hypoplasia, stunted growth and increases the animal's susceptibility to infection
 
*Animal usually dies from pneumonia or sepsis as the level of maternal [[Immunoglobulins - WikiBlood|antibody]] decreases
 
 
 
====Selective IgA deficiency of German Shepherd Dogs====
 
*Poorly understood
 
*Linked to other disease syndromes such as deep pyoderma, inflammatory bowel disease, anal furunculosis and disseminated aspergillosis
 
*[[Immunoglobulin A - WikiBlood|IgA]] deficiency so more susceptible to mucosal disease
 
 
 
====Immunodeficiency of Weimaraners, Irish Wolfhounds and Miniature Dachshunds====
 
*Unknown aetiology
 
*Inherited defects
 
*Low levels of circulating [[Immunoglobulin M - WikiBlood|IgM]] and [[Immunoglobulin G - WikiBlood|IgG]]
 
*Impaired [[Neutrophils - WikiBlood|neutrophil]] function
 
*Causes recurrent pyrexia and infections
 
**E.g. Rhinitis and bronchopneumonia in Irish Wolfhounds due to low [[Immunoglobulin A - WikiBlood|IgA]]
 
**E.g. Pneumocytosis in Miniature Dachshunds due to low [[Immunoglobulin G - WikiBlood|IgG]]
 
 
 
===Labatory Examples of Severe Combined Deficiency===
 
[[Image:Nude Mouse.jpg|right|thumb|150px|Nude Mouse - Copyright Michigan State University- Carcinogenesis Laboratory]]
 
*Severe Combined Immune Deficiency(SCID)
 
**No functional [[Lymphocytes - WikiBlood#B cells|B cells]] or [[Lymphocytes - WikiBlood#T cells|T cells]]
 
 
 
*Athymic nude mice (no [[Thymus - Anatomy & Physiology|thymus]])
 
**No functional [[Lymphocytes - WikiBlood#T cells|T cells]]
 
**Cell-mediated immunodeficiency
 
 
 
*Knock-out mice
 
**E.g. Gene coding for  CD4, CD8, IL-10 removed
 
 
 
==Secondary Immunodeficiency==
 
 
 
*There are many causes of secondary immunodeficiency
 
**Most deficiencies are not genetic
 
**Most are agent-induced, such as from X-ray radiation and immunosuppressive drugs
 
 
 
===Viral Causes===
 
 
 
====Feline Leukaemia Virus (FeLV)====
 
[[Image:FeLV Electron Micrograph.jpg|thumb|right|150px|FeLV Electron Micrograph [http://phil.cdc.gov/phil/home.asp Public Health Image Library] Image #5610]]
 
[[Image:Kinetics of FeLV 2.jpg|thumb|right|150px|Kinetics of FeLV - Copyright Dr Brian Catchpole BVetMed PhD MRCVS]]
 
*Oncogenic retrovirus
 
*Causes neoplasia (lymphoma), myelosuppression (anaemia) and immunosuppression (of [[Lymphocytes - WikiBlood#T cells|T cells]])
 
*2 strains:
 
**FeLV-A
 
***Natural strain
 
**FeLV-B
 
***Formed through FeLV-A recombining with endogenous retroviral sequences in the feline genome
 
***Increases the risks of lymphoma
 
**FeLV-C
 
***Formed from the spontaneous mutation of FeLV-A
 
***Is more myelosuppressive
 
*Virus replicates in the oropharyngeal lymphoid tissue causing a viraemia (virus circulating in the bloodstream) which then spreads to the systemic lymphoid tissue
 
*Shed in saliva
 
*Passed by oronasal route, e.g. mutual grooming
 
*Kittens between 6 weeks and 6 months are most susceptible
 
*60% of cats will become immune to the disease and recover
 
*Cats that are persistantly viraemic will progress to develop FeLV-associated diseases
 
*Some cats will become viraemic again if treated with corticosteroids or stressed if the infection lies dormant in the [[Bone Marrow - Anatomy & Physiology|bone marrow]]
 
*Diagnosis:
 
**ELISA
 
**Rapid-Immuno-Migration
 
**Western Blot
 
**Virus Isolation
 
**Immunofluorescence
 
**PCR
 
*Treatment:
 
**Antibiotics for secondary infection
 
**Anti-retroviral therapy
 
*For vaccinations see [[Vaccines - WikiBlood#Cat Vaccinations|here]]
 
 
 
====Feline Immunodeficiency Virus (FIV)====
 
*Lentivirus
 
*Subtypes A, B and D
 
*Causes increased suscepitbilty to infections and neoplasia
 
*Specifically destroys [[Lymphocytes - WikiBlood#Helper CD4+|CD4+ T cells]]
 
*Virus is present in saliva, blood and other bodily fluids
 
*Feral and outdoor cats (mostly tom cats) are most at risk
 
*Virus replicates in lymphoid tissue
 
*Can remain asymptomatic
 
*Causes pyrexia and lymphadenopathy
 
*Transmitted by biting
 
*Diagnosis:
 
**ELISA
 
**Rapid-Immuno-Migration
 
**Western Blot
 
**Virus Isolation
 
**Immunofluorescence
 
**PCR
 
*Treatment:
 
**Antibiotics for secondary infection
 
**Anti-retroviral therapy
 
*For vaccinations see [[Vaccines - WikiBlood#Cat Vaccinations|here]]
 
 
 
====Bovine Immunodeficiency Virus (BIV)====
 
*Lentivirus (non-oncogenic)
 
*Causes a persistent viral infection and lymphocytosis
 
*Immunocompromised cattle may develop secondary infections
 
*The tranmission is not well known, but the following possibilities are being researched:
 
**Through milk
 
**Through infected semen (e.g.artificial insemination)
 
**Placental transfer
 
*Diagnosis:
 
**Western Blot
 
**PCR
 
 
 
===Toxic Causes===
 
 
 
*Poisons
 
 
 
===Iatrogenic Causes===
 
 
 
*Drugs
 
**Corticosteroids
 
**Ciclosporin
 
**Cytoxic cancer therapy
 
 
 
===Other Causes===
 
 
 
*Malnutrition
 
 
 
*Chronic disease
 
 
 
*Stress
 
 
 
*Senescence
 
 
 
==Links==
 
 
 
'''Internal'''
 
*[[Viruses|Viruses - WikiBugs]]
 
 
 
*[[Innate Immune System - WikiBlood]]
 
 
 
*[[Adaptive Immune System - WikiBlood]]
 
 
 
'''External'''
 
*[http://www.bitoheavencollies.com/GrayCollie.html| Grey Collie Syndrome] ''Information on Canine Cyclic Haematopoeisis (Grey Collie Syndrome) including new research into treating the condition and a clinical example''
 
 
 
*[http://carcino.com.msu.edu//mouse.html| Nude Mice] ''Information on nude mice and their role in cancer research''
 
 
 
==[[Immunodeficiencies Flashcards - WikiBlood|Immunodeficiencies Flashcards]]==
 
 
 
==References==
 
'''Books'''
 
 
 
*Ivan Roitt: '''Essential Immunology,''' Ninth edition
 
 
 
*Goldsby, Kindt, & Osbourne '''KUBY Immunology,''' Fourth edition
 
 
 
'''Lecture Notes'''
 
 
 
*Dr Brian Catchpole BVetMed PhD MRCVS
 
 
 
'''Websites'''
 
 
 
*Michelle Tennis & Peggy Melton http://www.bitoheavencollies.com
 
 
 
*http://carcino.com.msu.edu/mouse.html
 
 
 
==Creators==
 
 
 
[[Natalie Brown]]
 

Latest revision as of 13:36, 12 August 2010