Pathogenesis of Autoimmune Disease Flashcards
what is rheumatoid arthritis (RA)?
synovitis
chronic joint inflammation and therefore joint damage, pain and stiffness
SYMMETRICAL
what are the associated anti-antibodies in RA?
o Rheumatoid factor.
o Anti-cyclic citrullinated peptide (CCP) antibodies
what is ankylosing spondylitis?
enthesis
chronic spinal inflammation causing spinal fusion and deformity.
what are the associated auto-antibodies in anky.spond?
none
seronegative disease
what are some examples of seronegative spondyloarthropathies?
spondyloarthropathies are seronegative by definition (shown by the absence of rheumatoid factor)
o Ankylosing spondylitis. o Reiter’s syndrome (reactive arthritis) o Psoriatic arthritis – arthritis associated with psoriasis. o Enteropathic synovitis – arthritis associated with GI inflammation.
what is systemic lupus erythematosus (SLE)?
immune complexes mediated
Chronic tissue inflammation from antibodies directed against self-antigens.
usually involves skin, joints, kidneys and other organs
which site does SLE commonly inflame?
joints
skin
kidneys
what are the associated auto-antibodies in SLE?
o Anti-nuclear antibodies.
o Anti-double-stranded DNA antibodies.
what are some examples of connective tissue disorders?
- SLE
- Inflammatory muscle disease (polymyositis, dermatomyositis)
- Systemic sclerosis
- Sjogren’s syndrome
- “Overlap” syndromes (mixtures)
what HLA is associated with RA?
HLA-DR4
what HLA is associated with SLE?
HLA-DR3
what HLA is associated with anky.spond?
HLA-B27
what do HLA encode for?
MHC class I and II
which chromosome do HLA class I and II come from?
Chr 6
which chromosome does the beta 2 microglobulin of HLA class I come from?
Chr 15
what do HLA molecules do?
present to T cells
o Class 1 –> CD8+ T-cells (cell killing).
o Class 2 –>CD4+ T-cells (helper T-cells).
T cells are MHC restricted i.e. only method of seeing an antigen
describe the structure of the peptide binding site for HLA molecule to T cells?
o Walls - alpha-helical structures.
o Floor - beta-pleated sheet.