Immunodeficiency Diseases Flashcards
Immunodeficiency diseases
Loss in function of parts of the immune system that causes the immunodeficient patient more susceptible to infectious diseases
What are the 2 types of immunodeficient states?
Primary and secondary
Primary immunodeficient state
Mutation in a gene encoding molecule of the immune system: an inherited or congenital disease
Inhibits development of both B and T cells
Secondary immunodeficient state in an adult animal
Due to age, malnutrition, infection, neoplastic or other chronic inflammatory diseases or due to the administration of immunosuppressive drugs
Recognition of immunodeficiency diseases in patients
- Disease occurring in young littermate animals with onset shortly after the expected time of loss of maternally derived immunity
- Disease affecting a particular breed
- Chronic and recurring infections
- Unusual infectious agents
- Incomplete response to treatment
- Failure of infection to respond to standard antimicrobial therapy
- Infection with environmental saprophytes
- Persistant lymphopenia or hypogammaglobulinemia
- Failure to respond to vax
Sever Combined Immune Deficiency Disease (SCID)
Fatal disease where poor B and T cell development results in lymphopenia, marked serum IgM and IgA deficiency, and hypoplasia of lymphoid tissues (2/3 to diagnose)
What causes SCID?
Lack of activity of the enzyme DNA-PK from a deletion mutation of the gene encoding the catalytic subunit
DNA-PK
Required for gene rearrangement of the antigen-receptor on B and T cells
What is the mode of inheritance of SCID?
Autosomal recessive
How do you diagnose SCID?
DNA test of whole blood or cheek swab
Should be performed in all Arabian and Arabian-crossbred horses
Phenotype of SCID
SCID foals are normal @ birth but show symptoms of increased temp, resp stress, and diarrhea (2-8 weeks of age)
Genotype of SCID
N/SCID = carriers (50% of offspring) and mating between 2 carries is 25% of affecting foal
SCID/SCID= fatal
Treatment and prognosis of SCID?
No treatment, die @ 4-6 months
Abscessation of the lung
Lymphoid tissue hypoplastic
Where is canine SCID recognized?
Basset hound, Cardigan Welsh Corgi, Jack Russel Terrier
XSCID fatal in humans by 2 and in dogs by 4 months unless treated with bone marrow transplantation
IgA deficiency
Most common human primary immunodeficiency disorder
Normal lives with chronic recurrent mucosal infections or have autoimmune, allergic or neoplastic diseases
Deficiency in IgA production
Equine Ig infections
Selective IgM deficiency, IgG deficiency and primary agammaglobulinemia (absence of B cells and all Igs)
What happens to foals with selective IgM or IgG deficiencies?
Develop recurrent infections of mucosal surfaces
What happens to adult horses (<3) with selective IgM or IgG deficiencies?
Recurrent infections, low to undetectable concentration of serum Igs and undetectable B cells
Fell Pony Syndrome
Inherited in autosomal recessive
Immunodeficiency disorder with deficiency of B cells and plasma cells
Mutation of chromo ECA26
Clinical signs of Fell Pony Syndrome
Anemia and respiratory enteric infections
Loss of maternally derived Ab and affected foals die by 3 months