Rheumatology Flashcards
What is the definition of Rheumatoid Arthritis (RA)?
Symmetrical inflammatory arthritis affecting mainly the peripheral joints which if untreated can potentially lead to joint damage and irreversible deformities
Who is more commonly affected by rheumatological conditions, men or women?
Women (beaut.)
What mediates RA?
A major histocompatibility complex class II allele human leukocyte antigen: HLA-DR4
What is the main structure involved in RA?
the synovium (lines joint capsules and tendon sheaths)
True or False, the first two joints of the spine, C1/C2 can be affected by RA
True, because they are lined by synovium
Which joints are preserved in synovitis of RA?
Distal interpharyngeal joints
What defines RA as early RA?
Less than 2 years since symptom onset
What tests should be done in RA?
Blood testing, inflammatory markers, autoantibodies and imaging (x-rays of hands and feet and US for signs of synovitis)
True or False, diagnosis of RA is dependent on detection of auto-antibodies
False, it is a clinical diagnosis
Which auto-antibodies are associated with RA?
Rheumatoid factor (not as specific) and Anti-CCP (very specific)
Which score is used to assess disease activity in RA, and what are the classifications based on results?
DAS 28 score ( >5.1 = active disease, 3.2-5.1 Moderate disease, 2.6-3.2 = low disease activity, <2.6 = remission)
What is the primary treatment for RA?
DMARDs: Methotrexate, with NSAIDs and steroids only as adjuncts in early stages while waiting for DMARDs to take effect
What are the first and second line DMARDs, and other options in RA?
Methotrexate and Sulfasalazine (alternatively Hydroxychloroquine, Leflunomide and combination therapy)
Why must a baseline CXR be taken with Methotrexate?
Risk of pneumonitis (allergic reaction in the lung)
What risks are there with Methotrexate?
Pneumonitis, liver function derangement, bone marrow suppression, tetrogenic effects
What is the starting dose of Methotrexate in RA?
15mg/week with rapid escalation until state of clinical remission is achieved (max 25mg/week)
What are examples of biologic agents?
Anti TNF agents primarily: Infliximab, Etanercept, Adalimumab, Certolizumab, Golimumab (or T cell receptor blockers, B cell depletes, IL-6 blockers or JAK 2 inhibitors)
What are the guidelines for biologic agent use in RA?
- Used when failure to respond to 2 DMARDs including Methotrexate and DAS 28 greater than 5.1 on two occasions 4 weeks apart.
- Methotrexate therapy is co-prescribed.
- Screen for latent or active TB , Hep B, C, HIV, Varicella zoster.
- Avoid live attenuated vaccines.
What are some complications of untreated RA?
Swan necking, Boutonnière’s, calluses, atlante-axial subluxation
What is the definition off Osteoarthritis?
Progressive degenerative condition affecting joints due to gradual thinning of cartilage, loss of joint space and formation of bony spurs (osteophytes) - essentially ‘wear and tear’
What is the pathogenesis of OA?
There is loss of matrix, release of cytokines including IL-1, TNF and mixed metalloproteinases as well as prostaglandins by the chondrocytes. Fibrillation of the cartilage surface and attempted repair with osteophyte formation then occurs (overstimulation of the bone)
What are some of the clinical signs of OA?
Heberdens nodes (bony enlargements at DIPs), squaring of thumb, osteophytes, effusions, crepitus at joints, varus/valgus deformities, restricted movement
What tests are done in OA?
Inflammatory markers, X-ray
** What are the main differences between RA and OA?
.
What is seen on x-ray in OA?
Loss of joint space, osteophytes, subchondral sclerosis and subchondral cysts (LOSS)
What are the pharmacological managements of OA?
Analgesia (eg. paracetamol), NSAIDs, Pai modulators (eg. tricyclics - amitriptyline, anticonvulsants - gabapentin), intraarticualr steroids
What are the surgical options for OA?
Arthroscopy (clear out joint) and joint replacement
Crystals of which type and form are seen in pseudo gout?
Calcium pyrophosphate crystals which are Rhomboids shaped and weakly positively birefringent
Crystals of which type and form are seen in gout?
Monosodium rate which are negative bifringement and needle shaped
Which level of serum uric acid defines hyperuricaemia?
> 7 mg/dL
What is the diagnostic criteria of gout, hyperuricaemia or crystal identification/radiographic findings?
Crystal identification/radiographic findings - not everyone with hyperuricaemia will develop gout
When does Chronic Polyarticular Gout occur?
If gout is left untreated
What is a tophi?
A deposit of crystalline uric acid and other substances at the surface of joints or in skin or cartilage, typically as a feature of gout
Which investigations are carried out in gout?
Inflammatory markers, WCC, X-ray (only see changes in chronic gout) and joint aspiration as the gold standard
What is the management of an acute attack of gout?
NSAIDs, colchicine or corticosteroids + other analgesics
What is used in the prophylaxis of gout?
Allopurinol
What is Milwaukee shoulder?
Another crystal arthropod with hydroxyapatite crystal deposition in or around the joint
True or False, Connective Tissue Diseases are diseases of the connective tissues
False (I know, don’t even get me started). They are autoimmune multi system diseases
What are etiological factors in SLE?
Genetics, increased oestrogen exposure, viruses eg. Epstein-Barr, UV light and silica dust
What is the pathogenesis of SLE?
Primarily due to loss of immune regulation. Involves increased and defective apoptosis, due to defective clearance of nuclear material acting as auto antigens
What likely causes renal disease in SLE?
Likely due to deposition of immune complexes in mesangium