RA Etiology:
- Genetic
- Enviro
- Antibodies
Genetic: MHC region for HLA-DR genes, SNPs of STAT4, PTPN22, TRAF1
Enviro: smoking, silica, pollution, viruses, bacteria
Antibodies to citrullinated/ carbamylated proteins –> immune complex, complement activation, inflammation, NETosis, osteoclast-genesis/activation, adaptive immune system
RA Classification Criteria
2010: ACR/EULAR: 6 or more
DDx RA
Uncommon:
- Infectious: endocarditis, rheumatic fever, Lyme
- Metabolic: hypothyroid, hemochromatosis, hyperlipoproteinemias (types II, IV), amyloid arthropathy
- Infiltrative: sarcoidosis,
- Vascular: hemoglobinopathies (sickle cell disease)
- Malignant: malignancy, paraneoplastic syndrome, hypertrophic osteoarthropathy,
- Inflamm: Behçet’s disease, Relapsing polychondritis, R3SPE, FMF, SAPHO
RA Epidemiology (race, age, prevalence)
All races (higher in Native Americans)
Age: 40-60 in F, older in M
1% of US
RA Patterns
b) Variant patterns of onset (10% of patients)
* Palindromic (episodic) pattern: Usually <5 joints and resolves within several days.- Tx: HCQ may decrease frequency of attacks and progression to RA.
* Insidious onset of elderly (>65 years): Pain/stiffness of limb girdle joints often with swelling of UE (difficult to differentiate from PMR & RS3PE)
* Arthritis robustus: Typically seen in men: bulky, proliferative synovitis –> erosions/ deformities with little pain or disability.
* Rheumatoid nodulosis: recurrent joint pain/swelling in, subcutaneous nodules, and subchondral bone cysts on XR.
RA Hand/Wrist deformities
Wrist:
- Volar subluxation (due to articular cartilage degradation and ligamentous laxity)
- Radial deviation (extensor carpi ulnaris tendon weakness = unopposed radial)
- Piano key ulnar head (radioulnar ligament damage –> floating ulnar styloid)
-Vaughan-Jackson deformity
MCPs:
- Subluxation (metacarpal head dorsally, prox phalanx head volar)
- Ulnar deviation
Fingers
- Ulnar drift (with wrist radial deviation, finger tendons pull fingers ulnarly)
- Fusiform swelling—PIP synovitis (spindle-shaped)
- Boutonnière
- Swan-neck
- Hitchhiker thumb (Z thumb)
Opera glass hands - bone resorption/shortening
RA XR findings
A—Alignment, abnormal; no ankylosis
B—Bones—periarticular (juxtaarticular) osteopenia; no periostitis or osteophytes
C—Cartilage—uniform (symmetric) joint space loss in weight-bearing joints; no cartilage or soft tissue
calcification
D—Deformities (swan neck, ulnar deviation, boutonnière) with symmetrical distribution
E—Erosions, marginal
S—Soft-tissue swelling; nodules without calcification.
RA C spine involvement
- subluxation
- impaction
- which joints
- neurologic manifestations
Manifestations:
-neck pain to occiput
-painless sensory loss (hands/feet)
- syncope/death
- cerebral ischemia w vertebral insufficiency
Rheumatoid Nodules
- Histology / Layers
RA Ocular Manifestations
RA Pulmonary Manifestations
RA Cardiac Manifestations
RA Neuro Manifestations
RA Heme Manifestations
RA Other manifestations
RA Derm Manifestations
Tx of Felty
DC SSZ (neutropenia)
RA Disease activity measures
DAS28
SDAI
CDAI
RAPID3
RA Markers of poor prognosis
RA Treatment targets
-how soon treatment
-activity level
Therapy within 3-6 mo of synovitis
Aim for LDAS or remission
SDAI calculation
Simplified disease activity index: TJC (0–28) + SJC (0–28) + PtGA (0–10) + PhGA (0–10) + CRP (mg/dL)
i.e. CDAI + CRP
CDAI calculation
Clinical disease activity index: TJC (0–28) + SJC (0–28) + PtGA (0–10) + PhGA (0–10)
RAPID calculation and cutoffs
Routine assessment of patient index data: MDHAQ (0–10) + patient pain (0–10) + PtGA (0–10)
Cutoff: <1, 1.3-2, 2.3-4, 4.3-10
RA Mortality causes
CV
Infection: PNA
Cancer: lymphoma, leukemia, lung, melanoma
Renal: amyloid
GI bleed: NSAID