MSKS Pathology Lecture 6_Mono and Polyarthropithies Flashcards
Osteoarthritis (OA) is charicterized by what?
degeneration of cartilage that results in structural and functional failure of synovial joints
What is the most common joint disease?
OA
What is primary and secondary OA and what is it’s prevelance?
Primary OA is OA associated with aging. 40% of people older than 70 have OA. Secondary OA is a result of some sort of joint deformity or injury and can occure in younger people. It accounts for 5% of OA cases
What causes OA
degeneration of the articular cartilage and its disordered repair
What does Matrix metalloproteinases (MMPs)?
secreted by chondrocytes degrades the type II collagen network leading to non-functional cartilage
As Rheumatoid Arthritis (RA) progresses, what two adverse and progressive effects does it have on the joints?
Leads to destruction of the articular cartilage and to ankylosis.
What is the prevalance of RA and its gender distribution?
It occures in about 1% of the US population. It is 3 times more common in women than in men
When does RA occur?
20s through 40s
What of risk for developing RA is inherited genetic susceptibility. What gene
50% of the risk is genetic and it is associated with the HLA class II locus.
How do infections and smoking promote auto immunity that leads to RA?
They promote citrullination (conversion of arginine into citrulline) of self-proteins, creating new epitopes that trigger autoimmune reactions
What is the Pathogenesis of RA?
CD4 helper T cells inniciate auto immune response and secreat cytokines that stimulate the production of INF-gamma, IL-17, RANKL, TNF and IL-1. These activate veriouse immune cells (nutrophils, macrophages, osteoclasts) and results in the destruction of catilage and reabsorption of bone
What are the 5 steps to the Morphology of RA?
(1) synovial cell hyperplasia and proliferation; (2)
dense inflammatory infiltrates of CD4+ helper T cells, B cells, plasma cells, and macrophages;
(3) increased vascularity; (4) neutrophils and aggregates of organizing fibrin on the synovial and
joint surfaces; (5) osteoclastic activity in underlying bone.
How is RA diagnosed?
the presence of anti-citric citrullinated preptide antibodies, and radiograhpic findings (joint effusions and juxtaarticular osteopenia with erosions,ulnar deviation, swan neck, etc)
What are two clinical differences between RA and OA?
OA is asymetric while RA is symetric. RA leads is inflamatory and causes swelling while OA does not.
What is rheumatoid factor
serum autoantibodies that bind to the Fc portions of their own IgG
