Rheumatology (Autoantibodies, DMARDs, Joint conditions) Flashcards
autoantibodies for RA
rheumatoid factor
anti-CCP (higher specificity)
autoantibodies for SLE
Presence of
- ANA - high sensitivity, not very specific
- Anti-dsDNA (more specific)
- Anti- Ro and Anti- La
During flare
- Raised ESR (normal CRP)
- decreased C3 and C4
Autoantibodies in Sjorgrens syndrome
- rheumatoid factor (RF) positive in around 50% of patients
- ANA positive in 70%
- anti-Ro (SSA) antibodies in 70% of patients with PSS
- anti-La (SSB) antibodies in 30% of patients with PSS
autoantibodies for systemic sclerosis
anti-Scl-70
anti-centromere
autoantibodies for granulomatosis with polyangiitis (Wegener’s granulomatosis)
Cytoplasmic ANCA (c-ANCA)
autoantibodies for eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
p-ANCA
autoantibodies for primary sclerosing cholangitis
p-ANCA
classification of DMARDS
Conventional DMARDS - broad immunosuppressive effects
- methotrexate
- sulfalazine
- hydroxychloroquine
Biologic DMARDs- genetically engineered proteins that target specific parts of the immune system
- TNF inhibitors e.g. infliximab
- B cell inhibitors e.g. rituximab
- Interleukin inhibitors
- T-cell inhib inhibitors
Targeted synthetic DMARDS- target specific immune system componenents
- Janus kinase inhibitors
- JAK1 and JAK2 inhibots
- Phosphodiesterase type 4-inhibitor
patients on DMARDs should seek immediate help if they have signs of
Blood disorders whose features may include:
* Sore throat
* Fever
* Bruising
* Mouth ulcers
Liver toxicity whose features may include:
* Nausea, vomiting, or abdominal discomfort
* Dark urine
Respiratory effects such as:
* Shortness of breath
Methotrexate
MOA
- antifolate
Dosing
- given once a week
- prescribed with folic acid and taken on different days to the methotrexate dosea
Contraindication
- pregnancy or trying for pregnancy (men and women)
- active infections
- do not breastfeed
Adverse reaction
- anorexia
- N and V
- diarrhoea
- mouth ulcers
- pneumonitis
- pulmonary fibrosis
- liver damage sich as hepaitits, cirrhosis or fibrosis
Monitoring
Pre-treatment screening:
* Pregnancy must be excluded before treatment
* Patients should have FBC, U&Es, and LFTs done before treatment
Monitoring:
* FBC, U&Es, LFTs every 1-2 weeks until therapy stabilised
* Then FBC, U&Es, and LFTs every 2-3 months
sulfalazine
MOA
- It metabolises into 5-aminosalicylic acid (5-ASA) which appears to play a bigger role in its therapeutic effect.
Contraindications
- Salicylate hypersensitvity
Interactions
- concomitnant use with azathiprine may cause bone marrow suppression
Adverse effects
- nausea
- oral ulcerrs
- myelosuppression
- Oligospermia
- SJS and TEN
- cough
- intersititial lung disease
Monitoring
* FBC including white cell differential and platelet count, U&Es, and LFTs must be done initially and monthly during the first 3 months
* After 12 months, monitoring may be stopped
hydroxychloroquine
MOA
- not fully understood
Contraindications
- known hypersensitivity
- eye problems
Interactions
- Hydroxychloroquine prolongs the QT interval, avoid using it with any drugs that prolong the QT interval e.g. amiodarone, clarithromycin, citalopram etc.
Adverse effects
* Photosensitive skin rashes
* Nausea
* Dyspepsia
* Diarrhoea
* Headaches
* Hair loss
* Tinnitus
* Visual problems – retinopathy
Monitoring
- Baseline ophthalmological examination (fundus photography and spectral domain optical coherence tomography) and annually following
Pregnancy and breastfeeding
- May be used in pregnancy if needed
- May be used if breastfeeding, small amounts may be present in milk
Biologic DMARDs
Adverse effects
- The main adverse effect is that anti-TNF medication can reactivate latent tuberculosis as TNF-α is needed to maintain the latent state.
Monitoring
- FBC, U&Es, and LFTs at 3-4 months, then every 6 months
- Lipids 4-8 weeks after starting treatment
If indicated: assessment for hepatitis B, hepatitis C, tuberculosis, or HIV
Osteoarthritis (OA)
is a degenerative joint disorder whose prevalence increases with age. It’s also known as the “wear and tear” of joints.
OA commonly affected joints
- Knee
- Hip
- PIP and DIP
- the spine (lumbar and cervical regions)
OA Risk Factors & Associations
- > 50yrs
- Female sex
- Family history of OA
- Obesity
- Physically demanding occupation
- Sports
- Trauma/injury
- Hypermobility
presentation of OA
worse on activity and relieved with rest
- morning stiffness that lasts <30 mins
- history of long term physical labour
- PIP and DIP joints affacted (spares MCP joint)
- localised tnederness over joint line
- Knee locking or giving way
- Bony deformity
- active and passive range of movement may be reduced and painful
OA signs on examiantion
- Squaring of the base of the thumb (first carpometacarpal joint) is a sign of hand OA
- In advanced knee OA: new bone formation causes bony swellings around the knee joint
- Enlargement of the DIP joints – Heberden nodes
- Enlargement of the PIP joints – Bouchard nodes
- There may be palpation of crepitus during movement of the joint
- There may be small effusions
- There may be joint line tenderness
- Patients may have an abnormal gait
x-ray findings for OA
LOSS
- Loss of joint space
- Osteophytes
- Subchondral sclerosis
- Subchondral cysts
OA vs RA
- Usually a symmetrical small joint polyarthritis affecting the MCP and PIP joints and may spare the DIP joints
- RA is associated with prolonged morning stiffness (>30 minutes)
- Joint pain and stiffness are worse with rest and improve with movement
- There can also be evidence of systemic upset, such as fatigue, low mood, and fever
Management of OA
First line
- Weight loss if appropriate
- Muscle strenghthening
- Paracetamol and topical NSAIDs for OA of the hand or knee
Second line
- Oral NSAID/COX-2 inhibitor + PPI
Third line
- Intra-articular corticosteorid injections
Fourth line
- Joint replacement surgery - appropriate if OA having significant impact on QoL
RA
is an autoimmune disorder characterised by inflammation of the synovial membrane leading to joint swelling, tenderness, warmth, and stiffness. This can also lead to destruction of the surrounding tissues and the joint. RA may also have extra-articular disorders.
Risk Factors for RA
- Family history
- Smoking
- HLA-DR4 or HLA-DR1
presentation of RA
RA typically presents with an insidious onset (generally over months) of symmetrical polyarthritis (arthritis affecting both sides equally) affecting the small joints of the hand and feet.
Pain
- worse with rest and improve with exercise
- prolonged moring stiffness >1 hour
Joint erythema and warmth
* Metacarpophalangeal (MCP) - positive MCP squeeze test
* Proximal interphalangeal (PIP)
* Metatarsophalangeal (MTP)
Joint swelling
- boggy or squishy around joint
Additional
* Rheumatoid nodules – hard swellings over extensor surfaces
* Extra-articular features (vasculitis or eye, lung, or heart involvement)
* Systemic upset (fever, fatigue, weight loss, night sweats, malaise)
RA signs on examination
- ‘Boggy’ swellings around joints
- Swan neck deformity – late-stage sign
- Boutonniere’s deformity – late-stage sign
- Ulnar deviation due to MCP inflammation
- Rheumatoid nodules on extensor surfaces of tendons
extra articular features of RA
vasculitis or eye, lung, or heart involvement)
investigations for RA
Autoantibodies
Rheumatoid factor (RF):
* High sensitivity, but around 1/3 of patients are RF-negative
Anti-cyclic citrullinated peptide (anti-CCP) antibody:
* High specificity, positive in around 80% of people with RA
Imaging
X-ray of the hands and feet – in all patients with RA:
* Helps with diagnosis and determination of disease severity
* May show loss of joint space, juxta-articular osteoporosis, soft tissue swelling, periarticular erosions, or subluxation
Other investigations to consider are:
C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR):
* Non-specific markers of inflammation
Full blood count, urea and electrolytes, and liver function tests:
* Guides treatment and identifies comorbidities
XRAY finding RA
LESS
L – loss of joint space
E – erosions
S – soft tissue swelling
S – soft bones (osteopenia)
psoriatic arthritis
Psoriatic arthritis (PsA) is a seronegative inflammatory arthritis affecting joints and connective tissue and is associated with psoriasis of the skin or nails. PsA can occur without the presence of skin disease, or the rash may be difficult to notice.
PsA may affect the tendons surrounding the joints as well as the joints themselves. This can lead to swelling of the whole digit (dactylitis) or enthesitis (inflammation of the entheses, the sites where tendons or ligaments insert into the bone).
It is a progressive disorder ranging from mild synovitis to severe progressive arthropathy. Around 40-60% of patients with psoriatic arthritis develop erosive and deforming joint complications.
gout presentation
Gout typically presents acutely (over hours)
Acute severe joint pain, swelling, and warmth– may occur overnight
- Typical joints affected are in the feet, most cases occur in the first metatarsophalangeal joint (MTP) of the foot
- Usually monoarticular or oligoarticular (<5 joints)
- It may be polyarticular in older people
Gouty tophi may be present – these suggest longstanding, untreated gout
- They are seen on extensor surfaces of affected joints, Achilles tendons, dorsal hands and feet, and the helix of the ear
presentation of AS
Suspect AS in a patient aged 20-30 with an insidious onset of lower back pain. Features include:
Inflammatory joint pain:
- Pain and stiffness improve with movement and are worse with rest
- Prolonged morning stiffness (usually >1 hour)
- There may be pain at night that wakes the patient up
Enthesitis
- Achilles tendonitis, tibial tuberosity enthesitis, plantar fasciitis
- Dactylitis – swelling of a digit (sausage like swelling)
Peripheral arthritis – there may be involvement of lower limb joints
Fatigue
Extra-articular features and complications:
- Anterior uveitis
- Apical lung fibrosis
