Rheumatoid Arthritis Flashcards
Inflammatory joint pathologies are generally characterized by an ____ response
osteolytic
Degenerative joint pathologies are generally characterized by an ____ response
osteoblastic
Inflammatory joint pathologies have potential for what type(s) of joint fusion?
fibrous or osseous
If Rheumatoid arthritis (RA) creates ankylosis, it is usually what type?
fibrous
RA generally occurs (unilateral/bilateral) and (symmetrical/asymmetrical)
bilateral
symmetrical
Inflammatory joint pathologies are not just arthropathies, they are ____ inflammatory conditions
systemic
What is the most common inflammatory arthropathy?
Rheumatoid Arthritis
In what age group does RA begin most commonly?
20s - 30s
(can occur at any age, biased toward younger)
RA generally affects ____ joints first, and moves to ____ joints
smaller to larger
Describe the involvement of the spine in RA
- rarely affected early
- ~80% of pts eventually experience c/s involvement (destruction of transverse ligament -> instability)
TRUE/FALSE:
A patient who complains of pain only in the distal interphalangeal joints is more likely to have RA
FALSE
(RA does not like DIPs in early stage)
TRUE/FALSE:
A patient who complains of pain only in the metacarpophalangeal joints is more likely to have RA
TRUE
(DJD doesn’t like MCP, RA does)
Most inflammatory conditions follow a symptomatic pattern of ____
exacerbation/remission
What are the clinical features of vasculitis in a patient with RA?
- painful rashes in hands & feet
- vasospasm (narrow lumen)
- ^risk of heart attack & stroke
What 2 factors contribute to the development of RA?
genetic & environmental
What 2 genetic factors are involved in RA?
- Human Leukocytic Antigen (HLA)
- PTPN22 deficiency
What is the role of HLA in RA?
involved in location of binding site for arthitogens that initiate inflammation
What is the role of PTPN22 in RA?
deficient in RA
normally encodes protein tyrosine phosphate which inhibits T-cell activation
What environmental factors are involved in the development of RA?
- infection
- smoking (decreases collagen formation)
- EBV (many different Ag’s; not proven)
Name the 5 steps in the pathogenesis of RA
- autoimmune response
- synovial hyperplasia & hypertrophy
- pannus proliferation
- cartilage & bone destruction
- fibrous or osseous ankylosis
What is involved in the autoimmune response in RA?
- CD4+ T-helper cells
- cytokines
What do IL-1, PGE2, and RANKL stimulate in RA?
osteoclasts & bone resorption
What does IFN-y activate in RA?
macrophages & resident synovial cells
What does IL-7 signal in RA?
neutrophils & monocytes
What do TNF and IL-1 stimulate in RA?
synovial cells to secrete proteases (destroy hyaline cartilage)
What causes synovial hyperplasia & hypertrophy in RA?
lymphocytes & plasma cells accumulate in synovium
Chronically inflamed synovium is called a _____
pannus
Describe how pannus proliferation occurs in RA
- enzymes & proteases ^ in joint
- ^vascularity (hemorrhage + hemosiderin deposition)
- covers articular cartilage, separating it from synovial fluid (less diffusion, starves cartilage)
- eventually fills entire joint space (jt. stiffness & decreased ROM)
What is the term used to describe the appearance of a pannus?
“frond-like” (fern-like)
What causes rice bodies in a joint?
^vascularity in a pannus brings small fibrin nodules which float in jt space
In general, what causes joint achiness in RA?
inflammation
In general, what causes joint stiffness in RA?
pannus formation
What causes cartilage destruction in RA?
proteases (chondrolytic enzymes) secreted by synovium destroy hyaline cartilage
What causes bone destruction in RA?
RANKL, PGE2, IL-1 stimulate osteoclasts
Why is joint space loss in RA uniform?
chemically mediated destruction of cartilage (not biomechanical)
Inflamed synovial tissue against the bare area causes ____ radiographically
marginal erosion
Bone destruction in the bone around a joint in RA causes ____ radiographically
periarticular (juxta) osteopenia)
Tendon sheathes and bursa are lined with ____
synovium
What causes ulnar deviation of the fingers in RA?
rupture of tendon pulleys allows tendons to pull to ulnar side (tendon subluxation)
What type of ankylosis is more common in RA?
Fibrous (uncommon) > osseous (rare)
How does the gross appearance of joints with RA compare to that of degeneration?
raw bloody bone instead of eburnation
(will also accelerate degenerative change)
What are the clinical manifestations of RA?
- gradual onset, exacerbation/remission pattern
- warm, swollen, painful jts (bilateral), crepitus
- ^pain with motion, worst after disuse (lasts longer than degenerative)
- tenosynovitis & lig. attachment destruction (creates deformities & sublux.)
- Rheumatoid nodules (*Haygarth’s nodes)
- secondary jt degeneration
- Anemia of chronic disease -> fatigue (marrow fibrosis)
- acute necrotizing vasculitis
What are examples of systemic manifestations of RA?
- emphysema (without smoking)
- pericarditis
- vasculitis
- liver/renal fibrosis
What joints are affected by Haygarth’s nodes?
MCP
What is the term for severe deformities of the digits in RA?
arthritis mutilans
What is a swan neck deformity?
flexion of DIP jt, extension of PIP jt
What is a Boutonniere deformity?
extension of DIP jt, flexion of PIP jt
What joints are most commonly affected by RA?
- wrists + MCP
- ankles + MTP
- PIP (does NOT prefer DIP)
- c/s
- elbow
- knee
What are common sites of Rheumatoid nodules?
elbow & legs
(can also occur in skin & visceral organs)
Describe the pathogenesis of acute necrotizing vasculitis that occurs in RA.
- inflammation of BVs
- vascular narrowing
- impaired blood flow to tissues
- ischemia and necrosis
How does acute necrotizing vasculitis manifest in RA?
- conjunctivitis
- ulcers
What are the relevant lab findings for RA?
- ^ESR & CRP
- positive rheumatoid factor (RF; 80%)
- positive Anticitrullinated protein antibody (ACPA; 60%)
- low RBC & platelets (anemia of chronic disease)
When should labs be taken in a patient with suspected RA?
during period of exaccerbation
What does rheumatoid factor represent?
multiple antibodies: IgM, IgG or directed against the Fc fragment of IgG
What is Anticitrullinated protein antibody (ACPA) also known as?
Anti-cyclic citrullinated peptides (anti-CCP Ab)
Which lab finding is more specific for RA?
ACPA
(less sensitive, more specific)
Which lab finding is more sensitive for RA?
RF
(less specific, more sensitive)
What are the radiographic characteristics of RA?
- osteolytic lesions at joint margins (marginal erosions AKA “rate bite” lesions)
- juxta/periarticular osteopenia
- bilateral, uniform loss of joint space
- pseudocysts
- deformities
- stair-step appearance in c/s (spondylolisthesis)
- ^atlanto-dental interspace due to destruction of transverse lig.
What are the treatment options for RA?
- low impact, regular activity
- anti-inflammatory diet
- drug therapy (NSAIDs, corticosteroids, DMARDs)
What drug therapy is used long-term for RA?
Disease modifying antirheumatic drugs (DMARDs)
Name 5 examples of DMARDs
- methotrexate
- TNF antagonists
- T-cell costimulatory blockers
- B-cell depleting agents
- IL-1 receptor antagonists
What is a common corticosteroid used for severe RA at the time of diagnosis?
Prednisone
