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
What are the three Seronegative Spondyloarthropathies
Ankylosing spondylitis, Reactive arthritis, and Psoriatic arthritis
What are the 5 main charisteristacs of Seronegative Spondyloarthropathies
• Absence of rheumatoid factor
• Pathologic changes in the ligamentous attachments
rather than synovium
• Involvement of sacroiliac joints, +/- other joints
• Association with HLA-B27
• Bony proliferation leading to ankylosis (fusion of joints)
When does Ankylosing spondylitis occure and what is the classic x-ray finding?
It becomes symptomatic in the second and third decades of life as lower back pain and spinal immobility. Its characteristic x-ray finding is bamboo spine (ossification of the intra transvers process ligaments)
Who is most effected by Reactive arthritis and what causes it? what joints are most effected
Men in their 20s and 30s are most effected. It is an auto immune response triggered by an UG infection (Chlamydia) of of the GI tract (Shigella, Salmonella, Yersinia, Campylobacter). Ankles, knees, and feet are most effected and in an asymetric manner.
Who is effected my Psoriatic arthritis and At what age? What is the classic x-ray finding?
It effects more than 10% of the population with the Psoriatic skin condition. Occurance typically arises between 30 and 50. The classic x-ray finding it “the pencil in cup”
What are tophi?
aggregates of urate crystals and inflammatory tissue in inflamed synovial membranes and periarticular tissue that result in repeated attacks of gout
What is the birefringent characteristics of gout?
It is negatively birefringent.
What are the risk factors for gout?
male sex, obesity, metabolic syndrome, excess alchohol intake, renal failure, and age >30 years.
