Difference between revisions of "Category:Immunodeficiencies"

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(Created page with "Immunodeficiencies - Introduction ==Primary Immunodeficiency== *Primary immunodeficiencies may affect either the innate immune system o...")
 
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[[Immunodeficiencies - Introduction]]
 
[[Immunodeficiencies - Introduction]]
  
==Primary Immunodeficiency==
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==[[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#T cells|T cells]] or [[Lymphocytes#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#T cells|T cell]] deficiencies can affect both the cell-mediated and humoral response as [[Lymphocytes#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, [[Diarrhoea|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|neutrophil]] migration and phagocytosis
 
*Recurrent bacterial infection
 
*Neutrophilia ([[Neutrophils|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|lymphocytes]] (e.g. Ig and TCR)
 
*No functional [[Lymphocytes#B cells|B cells]] or [[Lymphocytes#T cells|T cells]]
 
*Foals develop infections (usually around 8 weeks of age as maternal [[Immunoglobulins|antibody]] in [[Materno-Fetal Immunity - Introduction#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#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|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|[[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|IgM]] and [[Immunoglobulin G|IgG]]
 
*Impaired [[Neutrophils|neutrophil]] function
 
*Causes recurrent pyrexia and infections
 
**E.g. Rhinitis and bronchopneumonia in Irish Wolfhounds due to low [[Immunoglobulin A|[[IgA]]]]
 
**E.g. Pneumocytosis in Miniature Dachshunds due to low [[Immunoglobulin G|IgG]]
 
 
===Laboratory Examples of Severe Combined Deficiency===
 
[[Image:Nude Mouse.jpg|right|thumb|150px|Athymic Nude Mouse - Armin Kübelbeck 2008]]
 
*Severe Combined Immune Deficiency(SCID)
 
**No functional [[Lymphocytes#B cells|B cells]] or [[Lymphocytes#T cells|T cells]]
 
 
*Athymic nude mice (no [[Thymus - Anatomy & Physiology|thymus]])
 
**No functional [[Lymphocytes#T cells|T cells]]
 
**Cell-mediated immunodeficiency
 
 
*Knock-out mice
 
**E.g. Gene coding for  CD4, CD8, IL-10 removed
 
  
 
==Secondary Immunodeficiency==
 
==Secondary Immunodeficiency==

Revision as of 13:39, 12 August 2010

Immunodeficiencies - Introduction

Primary Immunodeficiency

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)

FeLV Electron Micrograph Public Health Image Library Image #5610
Kinetics of FeLV - Copyright Dr Brian Catchpole BVetMed PhD MRCVS
  • Oncogenic retrovirus
  • Causes neoplasia (lymphoma), myelosuppression (anaemia) and immunosuppression (of 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 persistently 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
  • Diagnosis:
    • ELISA
    • Rapid-Immuno-Migration
    • Western Blot
    • Virus Isolation
    • Immunofluorescence
    • PCR
  • Treatment:
    • Antibiotics for secondary infection
    • Anti-retroviral therapy
  • For vaccinations see here

Feline Immunodeficiency Virus (FIV)

  • Lentivirus
  • Subtypes A, B and D
  • Causes increased susceptibility to infections and neoplasia
  • Specifically destroys 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 here

Bovine Immunodeficiency Virus (BIV)

  • Lentivirus (non-oncogenic)
  • Causes a persistent viral infection and lymphocytosis
  • Immunocompromised cattle may develop secondary infections
  • The transmission 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
    • Cyclosporin
    • Cytotoxic cancer therapy

Other Causes

  • Malnutrition
  • Chronic disease
  • Stress
  • Senescence

Links

Internal

External

  • Grey Collie Syndrome Information on Canine Cyclic Haematopoeisis (Grey Collie Syndrome) including new research into treating the condition and a clinical example
  • Nude Mice Information on nude mice and their role in cancer research

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

Subcategories

This category has the following 2 subcategories, out of 2 total.

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Pages in category "Immunodeficiencies"

The following 2 pages are in this category, out of 2 total.