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| − | {{toplink
| + | #REDIRECT[[:Category:Immunodeficiencies]] |
| − | |backcolour = FFE4E1
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| − | |linkpage =WikiBlood
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| − | |linktext =WIKIBLOOD
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| − | |thispagemap= Immunodeficiencies(Concept Map) - WikiBlood
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| − | |sublink1 =Immunology - WikiBlood
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| − | |subtext1 =IMMUNOLOGY
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| − | |pagetype =Blood
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| − | }}
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| − | | |
| − | ==Introduction==
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| − | [[Image:Immunodeficiencies Map.jpg|thumb|right|150px|Immunodeficiency Diagram - Copyright nabrown RVC]]
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| − | 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.
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| − | 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.
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| − | Secondary immunodeficiency, sometimes called aquired immunodeficiency, is the loss of immune function during life, caused by exposure to harmful agents.
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| − | 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.
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| − | ==Primary Immunodeficiency==
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| − | | |
| − | *Primary immunodeficiencies may affect either the [[Innate Immune System - WikiBlood|innate immune system]]or [[Adaptive Immune System - WikiBlood|adaptive immune system]]
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| − | *They are categorised by either the type or the developmental stage of the cells involved
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| − | *Lymphoid cell disorders affect [[Lymphocytes - WikiBlood#T cells|T cells]] or [[Lymphocytes - WikiBlood#B cells|B cells]] (or both)
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| − | *Myeloid cell disorders affect phagocytic function
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| − | *The severity of the immunodeficiency depends on at which stage in development the problem occurs
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| − | **E.g. Defects early on in development will affect the entire immune system
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| − | *[[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
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| − | ===Deficiencies of Innate Immunity===
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| − | ====Canine Cyclic Haematopoiesis====
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| − | *Also called '''Grey Collie Syndrome'''
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| − | *Autosomal recessive
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| − | *Insertion mutation in AP3B1 gene
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| − | *Diluted grey coat colour, stunted growth, poor wound healing
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| − | *Neutropenia every 2 weeks which lasts 3-4 days due to cyclic production of cells from [[Bone Marrow - Anatomy & Physiology|bone marrow]]
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| − | *Recurrent infections, e.g. pyrexia, [[Intestine Diarrhoea - Pathology|diarrhoea]], gingivitis and arthritis
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| − | ====Canine Leukocyte Adhesion Deficiency (CLAD)====
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| − | *Occurs in Irish Setters
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| − | *Missence mutation of -Cys-36-Ser- in CD18 molecule
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| − | **CD18 is required for [[Neutrophils - WikiBlood|neutrophil]] migration and phagocytosis
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| − | *Recurrent bacterial infection
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| − | *Neutrophilia ([[Neutrophils - WikiBlood|neutrophils]] remain in the blood and are unable to fight infection in the tissue)
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| − | ====Bovine Leukocyte Adhesion Deficiency (BLAD)====
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| − | *Occurs in Holstein cattle
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| − | *Missence mutation of -Asp-128-Gly in CD18 molecule
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| − | *Recurrent infection, e.g. pneumonia
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| − | ===Deficiencies of Adaptive Immunity===
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| − | ====Equine Severe Combined Immune Deficiency (Equine SCID)====
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| − | *Autosomal recessive
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| − | *Occurs in 2-3% of Arabian foals
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| − | *Defect in DNA-dependent protein kinase gene
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| − | **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)
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| − | *No functional [[Lymphocytes - WikiBlood#B cells|B cells]] or [[Lymphocytes - WikiBlood#T cells|T cells]]
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| − | *Foals develop infections (usually aorund 8 weeks of age as maternal [[Immunoglobulins - WikiBlood|antibody]] in [[Materno-fetal immunity - WikiBlood#Passive transfer via colostrum|colostrum]] wanes around this time)
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| − | *Foals usually die from bronchopneumonia
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| − | ====Canine X-Linked Severe Combined Immune Deficiency (Canine SCID)====
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| − | *Affects Basset Hounds and Corgis
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| − | *X-linked recessive defect in the gene conding for the IL-2 receptor
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| − | **IL-2 receptor is a receptor for the cytokine IL-2 which causes [[Lymphocytes - WikiBlood#T cells|T cells]] to proliferate
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| − | *Causes lymphoid hypoplasia, stunted growth and increses the animal's susceptibility to infection
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| − | *Animal usually dies from pneumonia or sepsis as the level of maternal [[Immunoglobulins - WikiBlood|antibody]] decreases
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| − | ====Selective IgA deficiency of German Shepherd Dogs====
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| − | *Poorly understood
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| − | *Linked to other disease syndromes such as deep pyoderma, inflammatory bowel disease, anal furunculosis and disseminated aspergillosis
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| − | *[[Immunoglobulin A - WikiBlood|IgA]] deficiency so more susceptible to mucosal disease
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| − | ====Immunodeficiency of Weimaraners, Irish Wolfhounds and Miniature Dachshunds====
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| − | *Unknown aetiology
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| − | *Inherited defects
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| − | *Low levels of circulating [[Immunoglobulin M - WikiBlood|IgM]] and [[Immunoglobulin G - WikiBlood|IgG]]
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| − | *Impaired [[Neutrophils - WikiBlood|neutrophil]] function
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| − | *Causes recurrent pyrexia and infections
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| − | **E.g. Rhinitis and bronchopneumonia in Irish Wolfhounds due to low [[Immunoglobulin A - WikiBlood|IgA]]
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| − | **E.g. Pneumocytosis in Miniature Dachshunds due to low [[Immunoglobulin G - WikiBlood|IgG]]
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| − | ===Labatory Examples of Severe Combined Deficiency===
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| − | *Severe Combined Immune Deficiency(SCID)
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| − | **No functional [[Lymphocytes - WikiBlood#B cells|B cells]] or [[Lymphocytes - WikiBlood#T cells|T cells]]
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| − | *Arthymic nude mice (no [[Thymus - Anatomy & Physiology|thymus]])
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| − | **No functional [[Lymphocytes - WikiBlood#T cells|T cells]]
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| − | **Cell-mediated immunodeficiency
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| − | *Knock-out mice
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| − | **E.g. Gene coding for CD4, CD8, IL-10 removed
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| − | ==Secondary Immunodeficiency==
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| − | *There are many causes of secondary immunodeficiency
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| − | **Most deficiencies are not genetic
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| − | **Most are agent-induced, such as from X-ray radiation and immunosuppressive drugs
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| − | ===Viral Causes===
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| − | ====Feline Leukaemia Virus (FeLV)====
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| − | [[Image:FeLV Electron Micrograph.jpg|thumb|right|150px|FeLV Electron Micrograph [http://phil.cdc.gov/phil/home.asp Public Health Image Library] Image #5610]]
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| − | *Oncogenic retrovirus
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| − | *Causes neoplasia (lymphoma), myelosuppression (anaemia) and immunosuppression (of [[Lymphocytes - WikiBlood#T cells|T cells]])
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| − | *2 strains:
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| − | **FeLV-A
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| − | ***Natural strain
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| − | **FeLV-B
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| − | ***Formed through FeLV-A recombining with endogenous retroviral sequences in the feline genome
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| − | ***Increases the risks of lymphoma
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| − | **FeLV-C
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| − | ***Formed from the spontaneous mutation of FeLV-A
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| − | ***Is more myelosuppressive
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| − | *Virus replicates in the oropharyngeal lymphoid tissue causing a viraemia (virus circulating in the bloodstream) which then spreads to the systemic lymphoid tissue
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| − | *Shed in saliva
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| − | *Passed by oronasal route, e.g. mutual grooming
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| − | *Kittens between 6 weeks and 6 months are most susceptible
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| − | *60% of cats will become immune to the disease and recover
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| − | *Cats that are persistantly viraemic will progress to develop FeLV-associated diseases
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| − | *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]]
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| − | *Diagnosis:
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| − | **ELISA
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| − | **Rapid-Immuno-Migration
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| − | **Western Blot
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| − | **Virus Isolation
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| − | **Immunofluorescence
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| − | **PCR
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| − | **Antibiotics for secondary infection
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| − | **Anti-retroviral therapy
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| − | *For vaccinations see [[Vaccines - WikiBlood#Cat Vaccinations|here]]
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| − | ====Feline Immunodeficiency Virus (FIV)====
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| − | *Lentivirus
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| − | *Subtypes A, B and D
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| − | *Causes increased suscepitbilty to infections and neoplasia
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| − | *Specifically destroys [[Lymphocytes - WikiBlood#Helper CD4+|CD4+ T cells]]
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| − | *Virus is present in saliva, blood and other bodily fluids
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| − | *Feral and outdoor cats (mostly tom cats) are most at risk
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| − | *Virus replicates in lymphoid tissue
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| − | *Can remain asymptomatic
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| − | *Causes pyrexia and lymphadenopathy
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| − | *Transmitted by biting
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| − | *Diagnosis:
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| − | **ELISA
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| − | **Rapid-Immuno-Migration
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| − | **Western Blot
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| − | **Virus Isolation
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| − | **Immunofluorescence
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| − | **PCR
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| − | *Treatment:
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| − | **Antibiotics for secondary infection
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| − | **Anti-retroviral therapy
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| − | *For vaccinations see [[Vaccines - WikiBlood#Cat Vaccinations|here]]
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| − | ====Bovine Immunodeficiency Virus (BIV)====
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| − | *Lentivirus (non-oncogenic)
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| − | *Causes a persistent viral infection and lymphocytosis
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| − | *Immunocompromised cattle may develop secondary infections
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| − | *The tranmission is not well known, but the following possibilities are being researched:
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| − | **Through milk
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| − | **Through infected semen (e.g.artificial insemination)
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| − | **Placental transfer
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| − | *Diagnosis:
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| − | **Western Blot
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| − | **PCR
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| − | ===Toxic Causes===
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| − | *Poisons
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| − | ===Iatrogenic Causes===
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| − | *Drugs
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| − | **Corticosteroids
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| − | **Ciclosporin
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| − | **Cytoxic cancer therapy
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| − | ===Other Causes===
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| − | *Malnutrition
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| − | *Chronic disease
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| − | *Stress
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| − | *Senescence
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| − | ==Links==
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| − | *[[Viruses|Viruses - WikiBugs]]
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| − | *[[Innate Immune System - WikiBlood]]
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| − | *[[Adaptive Immune System - WikiBlood]]
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| − | ==[[Immunodeficiencies Flashcards - WikiBlood|Immunodeficiencies Flashcards]]==
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| − | ==References==
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| − | *Ivan Roitt: '''Essential Immunology,''' Ninth edition
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| − | *Goldsby, Kindt, & Osbourne '''KUBY Immunology,''' Fourth edition
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| − | *Dr Brian Catchpole BVetMed PhD MRCVS
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| − | ==Creators==
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| − | [[Natalie Brown]]
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