Autoimmune Diseases Flashcards
What are the two factors necessary for developing an autoimmune disease?
1) genetic susceptibility
2) environmental trigger
What are the four ways infection can cause loss of self-tolerance?
1) upregulate costimulators on APCs
2) express antigens that look like self
3) polyclonal B cell activation
4) tissue injury releases altered self antigens that activate T cells
If left untreated, what is the clinical outcome of immune mediated inflammation?
irreversible tissue damage
What is the mechanism of pathogenesis in SLE?
antinuclear antibodies form immune complexes that lodge in tissues and cause multi-organ tissue damage
Malar rash, discoid rash, non-erosive arthritis, renal dysfunction, and hematologic disorders are signs of what autoimmune disorder?
SLE
also see photosensitivity and proteinuria, blood: neutropenia, lymphocytopenia, thrombocytopenia, leukopenia, anemia
Citrullinated proteins lead to T cell activation and cytokine release, followed by B cell activation creating a pannus in a joint in what disorder?
RA
What is the autoantibody specific to RA and what does it have affinity for?
IgM rheumatoid factor which binds the Fc portion of IgG
Sjogren’s syndrome is the immune mediated destruction of what structures?
lacrimal and salivary glands
What are the symptoms of Sjogren’s syndrome?
keratoconjunctivitis-dry eyes, dry mouth, lymphocytic inflammation, fibrosis of the lacrimal and salivary glands
A diagnosis of Sjogren’s syndrome means your patient has a higher risk of developing what cancer?
marginal zone lymphoma
What are the two types of systemic sclerosis/scleroderma and what differentiates them?
diffuse (widespread skin, early visceral)
limited (skin fingers only, late visceral)
CREST syndrome is associated with what autoimmune disease? What does CREST stand for?
systemic sclerosis/scleroderma
calcinosis, reynaud’s syndrome, esophageal dysmotility, sclerodactyly, telangiectasia
What are the symptoms for dermatomyositis?
violaceous heliotropic rash on upper eyelids muscle weakness/myalgia lung disease vasculitis myocarditis
After diagnosing a patient with dermatomyositis, what should you do?
scan for likely cancer
What causes dermatomyositis?
activation of T cells in small blood vessels in the muscles and CT causing myocyte atrophy and muscle fiber necrosis
What is the cause of polymyositis and how is it different from dermatomyositis?
T cell activation from Jo 1 autoantibodyleades to inflammation around muscles fibers but no atrophy or vascular injury
What is the defining characteristic of Mixed CT disease?
presence of the anti-U1RNP antibody
Match the autoantibody to the disease it causes:
1) cyclic citrullinated peptide Ab
2) SSA/RO and SSB/LA
3) Jo 1
4) Scl70
5) anti-dsDNA and Sm and Ribosome P
1) RA
2) sjogren’s
3) polymyositis
4) scleroderma
5) SLE
What is the difference between a primary and secondary immunodeficiency?
primary is genetically determined and in infants 6mo-2yrs
seconday is a result of cancer, infection, malnutrition, immunosuppression
What are three factors that should give you a high index of suspicion for an immunodeficiency?
1) opportunistic infection
2) clinical /family history
3) FTT
If you run lab tests for B cell function, T cell function, phagocytic function, and complement, what would you be checking for?
an immunodeficiency B= Ig T= CBC + flow cytometry phago= CBC + blood smear complement= CH50
What is the genetic defect in X linked agammaglobulinemia?
mutation in X linked Bruton’s tyrosine kinase means B cells can’t mature
In what immunodeficiency do you see a lack of IgA?
Isolated IgA deficiency
Lab results with normal or increased IgM, little to no IgG, and no IgA or IgE with normal T cells would lead you to what cause?
mutation in x linked recessive gene for CD40 so CD4 T cells can’t activate B cells and macrophages and there is no class switching
What is DiGeorge syndrome?
3rd and 4th pharyngeal pouches don’t develop due to a deletion on 22q11 so there is no thymus or parathyroid
Finding a mutation in the gene for the x linked gamma chain subunit for cytokine receptor or in the gene for Adenosine deaminase would mean the patient has what immunodeficiency?
SCID
normal B cells, decreased T cells, decreased Ig
What is the defect in Wiscott Aldrich syndrome?
mutation in gene for x-chromosone linked WASP (links membrane receptors to cytoskeletal elements)
What would you expect to see in labs for someone with Ataxia telangiectasia?
decreased Ig M/G/A/E
decreased T cell function
genetic tests: mutation in DNA repair enzyme
What is Chediak Higashi syndrome?
CHS1/LYST vesicle trafficking regulatory protein deficiency
