Rheumatology Flashcards
What is the HLA allele associated with seropositive rheumatoid arthritis?
HLA - DRB1
What is the main environmental risk factor associated with seropositive rheumatoid arthritis?
Smoking
Combined with HLA-DRB1 -> confers very high risk
Also affects response to treatment
What are the key auto-antibodies involved in seropositive rheumatoid arthritis?
Anti-citrullinated protein antibodies (ACPA)
Rheumatoid factor
Can be detected up to 10 years before clinical disease
What is the “second hit” in rheumatoid arthritis?
The additional insult which promotes the actual migration of circulating cytokines into the synovium which causes clinical disease
What are the 4 kinase signalling pathways implicated in rheumatoid arthritis?
MAPK
SyK
NIK
Jak-Stat (most promising for therapeutics)
MCQ
All of the following have been identified as risk genes for rheumatoid arthritis except \_\_\_? A: STAT4 B: DRB1 C: PADI D: FOXP3 E: PTPN22
D: FOXP3
STAT4: involved in both RA and SLE
PADI: promotes formation of ACPA
PTPN22: if combined with DRB1 leads to early erosive disease
In rheumatoid arthritis, why do bony erosions occur peri-articular?
Bony erosions occur before cartilage erosion in RA.
This is the location where the cartilage no longer protects the bony surface
What are the key cells involved in bony erosions in rheumatoid arthritis?
Osteoclasts
In rheumatoid arthritis, which joints are typically affected first?
Which are spared?
Small joints first, symmetric
DIP sparing
How can arthropathy of rheumatoid arthritis and SLE be differentiated?
SLE: deformities should be passively reversible (unless very severe disease), and non-erosive
Different extra-articular features
What is Felty’s Syndrome?
Triad of rheumatoid arthritis, neutropenia, and splenomegaly
- Rheumatoid arthritis is typically severe, erosive, and seropositive
- Neutropenia is present in all patients
- Splenomegaly
What is rheumatoid factor?
Antibody against Fc portion of IgG
Short-lived, so can be used to monitor disease activity
Name 5 rheumatological conditions other than RA that Rheumatoid factor is positive in
Sjogrens
Cryoglobulinaemia
SLE
Sarcoid
Undifferentiated CTD
What non-rheumatological condition is rheumatoid factor frequently positive in?
Hepatitis B and C
What are some key XR findings in RA?
- Periarticular erosions
- Periarticular osteopaenia / osteoporosis
- Joint pace narrowing
- Deformities
What are the classic hand findings in RA?
- Ulnar deviation of fingers
- Dorsal wrist subluxation
- Boutonniere
- Swan-neck deformities
- Z deformity of thumb
In rheumatoid arthritis, what is the fastest acting medication to reduce inflammation?
Glucocorticoids
- for short-term symptom control whilst awaiting effect of DMARDs
What is the “anchor” medication in treatment of rheumatoid arthritis?
What is it reversed by?
Methotrexate 10-25mg weekly
- competitive folate analogue (need to give with folate)
- improves mortality and prevents flares
SEs: GI upset, myelotoxicity, transaminitis, hepatic fibrosis, pneumonitis
Reversed by folinic acid
What is the main alternative cDMARD to methotrexate in RA?
What is it reversed by?
Leflunomide 10-20mg daily
- can be used in poor renal function
SEs: diarrhoea, myelosuppression
Very long half-life, reversed by cholestyramine
What is the most common cause of premature death in patients with rheumatoid arthritis?
Cardiovascular disease
What are the TNF inhibitors used in rheumatoid arthritis? (5)
Infliximab (Remicade) 3 mg/kg intravenously, as a single dose at 0, 2 and 6 weeks, and thereafter every 8 weeks
Adalimumab (Humira) 40 mg subcutaneously, every 2 weeks
Etanercept 50 mg subcutaneously, once weekly
Golimumab 50 mg subcutaneously, every 4 weeks
Certolizumab pegol subcut 2-weekly (doesn’t cross the placenta)
What are the main risks with TNF inhibitors?
Infection
- can be reactivation
Malignancy
Which rheumatoid arthritis DMARDs are safe in pregnancy?
Hydroxychloroquine
Sulfasalazine
TNF inhibitors
Steroids at low doses
What is the classic histological appearance of IgG4 disease?
Steroeform fibrosis