Rheumatoid Arthritis Flashcards
What is the definition of rheumatoid arthritis?
Chronic autoimmune systemic illness characterised by symmetrical polyarthritis and other systemic features
Commonly affects small joints of hands, wrists, and feet
How is RA diagnosed?
Clinical diagnosis
There is a classification EULAR but not used to diagnose
Describe the epidemiology of RA
Approx. 200 new cases in Grampian
3:1 females to males
Peak at age 4h/5th decade but can occur any age after 16
Describe genetic factors for RA
50-60 genetic predisposition - rises 2-4% in siblings and 12-15% in monozygotic twins
HLA-DRbeta1 - sequence of amino acids at position 70-74 termed as shared as epitope
What are some environmental factors which contribute to RA?
Smoking and chronic infection - periodontal disease, EBV, and Parvovirus B19
What hormonal factors can contribute to RA?
Early age menopause
Low testosterone level in men
What are the symptoms of rheumatoid arthritis?
Pain, stiffness for more than 30 mins after period of inactivity, immobility, poor function and systemic symptoms
What are the clinical signs of rheumatoid arthritis?
Swelling, tenderness, warmth, redness, and limitation of movement
Bilateral makes diagnosis of RA
What is the distribution for RA?
Polyarthritis - more than 4 joints affected
Symmetrical
High inflammatory marker
Positive antibody
Where does RA usually target?
Synovium - so get synovitis (soft tissue swelling)
What is a sign of advanced disease in rheumatoid hands?
Swan neck deformities of fingers - hyperextension of proximal interphalangeal joints and hyperflexion of distal interphalangeal joints
Ulnar deviation over phalangeal joints
What is a sign of rheumatoid feet?
Subluxation of metatarsal phalangeal head of feet - feel like walking on stones and can cause skin ulceration
What are some systemic features of RA?
No specific - fatigue, weight loss, and anaemia
Specific - eyes, lung, nerves, skin and kidneys
Long term - CVS and malignancy (lung cancer and lymphoma)
What are some extra-articular manifestations of Rheumatoid?
Eyes - scleritis
Lungs - airway, pleural
Skin - rheumatoid nodules
GI
Neuro
Vascular
Cardiac
Renal
Haematology - Felty’s syndrome
What is Felty’s syndrome?
Triad of RA, splenomegaly and leucopenia (low WCC)
Where are common sites for rheumatoid arthritis?
Around elbow and around ulnar border of forearm
What is used for investigations for RA?
Baseline bloods - FBC, kidney function, liver function, CRP and ESR
Immunology - Rheumatoid factor
Anti cyclic citrullinated antibodies (anti-CCP)
X-ray - erosion cam be seen if not treated well
US
How is an US beneficial for RA?
Damage and ongoing inflammation can be seen
Describe the disease activity score
DAs more than 2.6 represents clinical remission
DAS more than 5.1 represents eligibility for biologic therapy as biologics are second line medications
What is the outcome for RA?
33% will stop working after 2 years
50% unable to work after 10 years
Usually have about 40 days sick leave a year
What are the therapeutic categories for RA?
NSAIDs used to reduce inflammation
Disease modifying anti-rheumatoid drugs
Biologics
Corticosteroids
Describe disease modifying anti rheumatoid drugs (DMARD)
Structurally unrelated small molecule drugs which have been demonstrated to have slow onset on disease activity and retard disease progression
Associated with identifiable toxicity profiles and risk of adverse effects
Need regular BP measuring
What DMARD therapeutics are used?
Methotrexate - main
Sulfasalazine
Hydroxychloroquine
Leflunomide
Once weekly medication
What side effects can DMARDS cause?
Inflammation of liver
Platelets and WCC decrease
Pneumonitis - allergic reaction
What is the approach to management of RA?
Early and aggressive intervention is key to obtaining optimal outcomes
Effective suppression of inflammation will prevent disability and improve symptoms
How early and how aggressive
What is used doe early and aggressive treatment of RA?
Sequential monotherapy
Combination - step up, step down and parallel
Treat to target
Describe biologics in arthritis
Immunology to target key aspects of inflammatory cascade
Large complex proteins
Work rapidly and generally well tolerated although important toxicities - infection risk
What biologics are used for RA?
Infliximab - IV - TNFaplha inhibitor
Anakinra - IL-1 inhibitor
Anti B cell therapy - Rituximab
Anti T cell therapy - Abatacept
Oral kinase inhibitors
What are the issues with biologics?
Enhanced response with co-prescribed with Mtx
Infection and possible malignancy
Cost
