Rheumatoid Arthritis

Overview

• Systemic disorder of unclear aetiology (Genetic and Environmental factors play a part)
• Chronic inflammation leads to joint destruction and deformity
• Early recognition and treatment crucial to limit progression as above
• Prevalence of 1% in whet populations, predominantly females in age 30-55 years
• Increased risk of CAD 

Genetic Factors:
Account for 50-65% of risk of developing RA
Shared Epitopes: HLA-DRB (DR4, DR14, DR1) are strong RFs
Polymorphisms including TNF alpha promoter PTPN22 and STAT 4

Hormonal Influence:

Risk reduced in women who have had children 

Further reduced by those who breast feed for a year or so

Disease activity subsides during pregnancy

Men have lower levels of androgenic hormones and higher level of estradiol

Environmental factors:

Smoking

Miners and Construction workers (?dust related)

Lower socio-economic groups

Diagnosis:

• Clinically a symmetrical polyarthropathy affecting small joints (MCP and PIP joints)
• Can be asymmetric and oligoarthritis 
• Associated Morning stiffness (>60mins)
• DIP and Lumbar spine spared usually
• Examination reveals soft boggy or fluctuant swelling and tenderness, with warmth and redness
• Reduced active and passive movement with active arthritis

Laboratory:

• Active inflammation: High CRP and ESR, Anaemia of chronic disease, High Plts, low albumin
• Synovial fluid analysis: High leucs (predominant neuts)
• RF present in 70% of patients
• Anti CCP present in 60% of patients
• ANA positive in 40% (non specific)
• Specificity of Anti CCP for RA is 95% when compared to RF which is 80%

Imaging:

• Xray reveals: Periarticular osteopenia, erosions, and symmetric joint space narrowing
• MRI shows bone marrow oedema and synovial proliferation as precursors to erosions

Extra-Articular manifestations:

• Constitutional: Fatigue, Weight loss
• Dermatologic: Rheum nodules, Ulcers, Vasculitis
• Opthalmolgic: Episcleritis, Scleritis, Keratoconjunctivitis sicca
• Haematologic: Aneamia of chronic disease, Thrombocytosis, Pancytopenia + splenomegally (Feltys), large granular lymphocyte syndrome
• Cardiovascular: premature CAD, chronic heart failure, pericarditis, secondary amyloidosis
• Pulmonary: Exudative Pleural effusion, Fibrosis, pulmonary nodules, BOOP, brochiectasis, cricoarytenoid disease producing stridor
• GI: Dry mouth
• Renal: Secondary amyloidosis
• Neuro: c1-c2 subluxation, Mononeuritis mulitplex, peripheral neuropathy

Treatment:

Aims are to reduce inflammation, maintain remission and preserve function

At each visit disease activity and damage needs assessing with questions about fatigue, weight loss, morning stiffness, joint pain, functional status and quantification with a scoring system, measurement of CRP/ESR, and imaging.

NSAIDs and Steroids Provide symptomatic relief but do not alter disease course.  Used PO and intrarticular DMARDs MTX Hydroxychloroquine Sulfasalazine Leflunomide Azathioprine Cyclophosphamide MMF Cyclosporine Immunosuppressive agents that slow and block autoimmune damage to joints. First line is MTX  Add on therapy of Hydroxy/sulfa in poorly controlled RA patients Biologic agents TNF alpha inhibitors (Etanercept, infliximab, adalimumab, golimumab, certolizumba pegol) T cell costimulation (Abatacept) Anti CD20 B cell depleting (Rituximab)  IL 6 receptor antagonist (Tocilizumab) Used if above therapies have failed. Prior to using all pts require: -       CXR -       Anti viral screen (HIV/Hep) -       TB screen -       Monitor for infections during treatment Live vaccines should be avoided in these patients Concurrent use of 2 or more biologics is not recommended Surgical Intervention Synovectomy Repair or tendon rupture Osteotomy for realignment  Joint fusion for stabilisation  Joint arthorplasty Specific concerns for RA patients: Pre op optimisation of FBC C Spine imaging  Risk of infection and bleeding post op Balancing risk of infection with immunosuppressive therapy and healing time Non pharmacological treatment: Patient education MDT approach: Phsyio/OT/Dietician Smoking cessation Yearly flu vaccine