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| [[Immunodeficiencies - Introduction]] | | [[Immunodeficiencies - Introduction]] |
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− | ==Primary Immunodeficiency== | + | ==[[Primary Immunodeficiency]]== |
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− | *Primary immunodeficiencies may affect either the [[Innate Immune System - WikiBlood|innate immune system]] or the [[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#T cells|T cells]] or [[Lymphocytes#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#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
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− | ===Deficiencies of Innate Immunity===
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− | [[Image:Grey Collie Syndrome.jpg|thumb|right|150px|Appearance of a puppy with Grey Collie syndrome - Copyright Michelle Tennis & Peggy Melton]]
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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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− | *Animals are prone to recurrent infections, mainly from the respiratory and gastrointestinal tract
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− | **E.g. pyrexia, [[Diarrhoea|diarrhoea]], gingivitis and arthritis
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− | *Puppies can be distinguished from other litter mates by the diluted grey colouring
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− | *Affected puppies show symptoms such as fever, joint pain and eye, skin and respiratory infections from 8 weeks of age
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− | *Affected animals rarely live beyond 2-3 years with most puppies dying within a few weeks of birth
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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|neutrophil]] migration and phagocytosis
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− | *Recurrent bacterial infection
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− | *Neutrophilia ([[Neutrophils|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|lymphocytes]] (e.g. Ig and TCR)
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− | *No functional [[Lymphocytes#B cells|B cells]] or [[Lymphocytes#T cells|T cells]]
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− | *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)
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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 coding for the IL-2 receptor
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− | **IL-2 receptor is a receptor for the cytokine IL-2 which causes [[Lymphocytes#T cells|T cells]] to proliferate
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− | *Causes lymphoid hypoplasia, stunted growth and increases the animal's susceptibility to infection
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− | *Animal usually dies from pneumonia or sepsis as the level of maternal [[Immunoglobulins|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|[[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|IgM]] and [[Immunoglobulin G|IgG]]
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− | *Impaired [[Neutrophils|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|[[IgA]]]]
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− | **E.g. Pneumocytosis in Miniature Dachshunds due to low [[Immunoglobulin G|IgG]]
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− | ===Laboratory Examples of Severe Combined Deficiency===
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− | [[Image:Nude Mouse.jpg|right|thumb|150px|Athymic Nude Mouse - Armin Kübelbeck 2008]]
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− | *Severe Combined Immune Deficiency(SCID)
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− | **No functional [[Lymphocytes#B cells|B cells]] or [[Lymphocytes#T cells|T cells]]
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− | *Athymic nude mice (no [[Thymus - Anatomy & Physiology|thymus]])
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− | **No functional [[Lymphocytes#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== | | ==Secondary Immunodeficiency== |