Autoimmune Disorders Flashcards
conditions in which damage to organs or tissues results from the
presence of autoantibody or autoreactive cells?
Autoimmune diseases
Great majority of undifferentiated lymphocytes that are processed through the thymus do not survive
Central tolerance
Maintained by a delicate balance between the T helper cell type 1 (Th1) and T helper cell type 2 (Th2) populations
Peripheral tolerance
refers to the fact that many individual viral or bacterial agents contain antigens that closely resemble self-antigens
Molecular mimicry
have been implicated as primary mediators of autoimmune disease, because they release proinflammatory cytokines
Th1 cells
reaction to foreign antigens is typically a?
Th2 response
play a central role in maintaining this balance and eliminating harmful autoimmune responses
T cells (Tregs)
Abnormal expression or function of key signaling molecules, dysregulation of cytokines, and changes in B-cell developmental subsets
Polyclonal B-cell activation
May be enhanced by organisms such as gram-negative bacteria and several viruses, including cytomegalovirus and Epstein-Barr virus (EBV)
Polyclonal B-cell activation
Chronic systemic inflammatory disease marked by alternating exacerbations and remissions
Systemic Lupus Erythematosus (SLE)
SLE peak age of onset is usually between?
20 and 40 years
who is more likely to be stricken by SLE men or women?
Women
in SLE Women are much more likely than men to be stricken, by a margin of
approximately?
10:1
in SLE there is a strong association with human leukocyte antigens (HLA) DR and DQ with?
Whites
in SLE in whites there is a strong association with?
human leukocyte antigens (HLA) DR and DQ
SLE Inherited deficiencies of complement components
C1q, C2, and C4
double the risk of developing lupus
estrogen containing contraceptives or hormone replacement therapy
clinical signs of SLE
- Join involvement (arthritis)
- Erythematous rash
- Butterfly rash
- Diffuse proliferative glomerulonephritis (DPGN)
- Renal failure
The first clue in the mystery of lupus was the discovery of the LE cell by?
Malcolm Hargraves
neutrophil that has engulfed the antibody-coated nucleus of another neutrophil. This phenomenon, which mainly appears in vitro, occurs when cells are damaged and release nuclear material
LE cell
trigger an increase in antibodies directed against DNA and stimulate production of platelet activating factor
Increased production of interleukin-10 (IL-10)
differs from the more chronic form of the disease in that symptoms usually disappear once the drug is discontinued
Drug-induced lupus
- found in the basement membrane
- enhances activation of the complement cascade, which contributes to the kidney damage seen with this disease
α-actin
may also react directly with proteins such as α-actin
anti-DNA antibody
When SLE is suspected, the first test typically done is a screening test for?
antinuclear antibodies (ANA)
extremely sensitive but low specificity
Fluorescent antinuclear antibody (FANA)
Double-stranded DNA (ds-DNA) antibodies are the most specific for SLE, because they are mainly seen only in patients with lupus. (confirmatory if found with low levels of C3)
Antinuclear antibodies
- hemoflagellate, as the substrate
- particularly sensitive assay for ds-DNA is an immunofluorescent test using
Crithidia luciliae
second major antibody found in lupus patients is
antihistone antibody
a nucleoprotein that is a major constituent of chromatin
Histone
Antibodies are also stimulated by DNA complexed to histone, known as
Deoxyribonucleoprotein (DNP)
Presence of antihistone antibody alone or combined with antibody to ss-DNA supports
diagnosis of drug-induced lupus