Immunology Flashcards
What are the 3 groups of immune mediated diseases which affect the joints?
1) Rheumatoid arthritis
2) Juveline arthritis
3) Spondyloarthritis
What is Rheumatoid arthritis?
chronic, inflammatory disorder
Which tissues does Rheumatoid arthritis target?
1) synovial lining of joints
2) bursae
3) tendon cheaths
4) cartilage
5) bone
What are the characteristic antibodies for Rheumatoid arthritis?
1) RF (Rheumatoid factor)
2) ACPA (anti-cyclic citrullinated peptide)
Are males or females more susceptible to Rheumatoid arthritis?
females
What is the role of HLA in Rheumatoid arthritis?
DR4 subtypes of DRB1 alleles may bind pathogenic epitopes (particualrly thsoe containing citrulline) and alter negative selection in the thymus
What is PTPN22?
Protein Tyrosine Phophatase Lyp in RA; active in hematopoetic tissues
What is PADI4?
Peptidyl Arginine Deiminase type IV in RA; enzyme whcih converts arganine to citrulline
What is the series of events in the immunobiology of RA?
- acute initiating events (tissue damaeg)
- synovial fibroblasts stimulated by damage
- innate immune system activated
- stimulation of adaptive immune responsive
Which types of T-cells are activated in the adaptive immunity of RA?
CD4+ Th1 and Th17
CD8+
How do Th17 cells enhance inflammation in RA?
produce cytokines which suppress Treg cells
Which bacterium are Th17 cells important in providing defense against intracellular bacteria?
M. tuberculosis
What is the Rheumatoid factor?
IgM anti-IgG with specificity to the Fc region of IgG
What is citrullination?
post-translational modification of arganine
What is the purpose of citrullination?
HLA-DR4 molecules preferentially bind to citrullinated peptides
What is the anti-cyclic citrullinated peptide (ACPA)?
measures IgG antibodies in RA
What does a positive ACPA test in early RA predict?
more severe disease with development of erosive arthritis sooner
What is the role of IL-1 in RA?
activates monocytes/macrophages to cause inflammation
What is IL-1Ra?
IL-1 receptor antagonist; produced constitutively and during inflammation and binds but does not activate IL-1 receptor
What is the role of TNF-alpha in RA?
inflammation; fever and macrophage activation
Which factors do monoclonal antibodies target in RA therapies?
1) TNK-alpha
2) IL-6 receptor
3) B cells
Which factors do TNF-receptors target in RA therapies?
TNF-alpha
Which factors do receptor antagonists target in RA therapies?
IL-1
Which factors do CTLa4-Ig fusion proteins target in RA therapies?
CD80/86
