Ep 104 – Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder that primarily affects the joints. Causing joint pain, stiffness, swelling and reduced joint motion, its exact cause is still unknown, but is believed to involve a combination of factors. In this episode, Dr Roger Henderson looks at the aetiology of RA, diagnostic testing and the management pathway for patients with the condition.

Key references

1. Pincus T and Sokka T. Best Pract Res Clin Rheumatol. 2001;15(1):139-70. doi: 10.1053/berh.2000.0131.
2. Cojocaru M, et al. Maedica (Bucur). 2010;5(4):286-91.
3. Colebatch AN, et al.Ann Rheum Dis. 2013;72(6):804-14. doi: 10.1136/annrheumdis-2012-203158.
4. Smolen JS, et al. Ann Rheum Dis. 2023;82(1):3-18. doi: 10.1136/ard-2022-223356.
5. Donahue KE, et al. Rockville (MD): Agency for Healthcare Research and Quality (US); 2018. Report No.: 18-EHC015-EFReport No.: 2018-SR-02.
6. Tugwell P, et al. BMJ. 2011;343:d4027. doi: 10.1136/bmj.d4027.

Key take-home points

• RA is a common, chronic inflammatory autoimmune disease characterised by joint inflammation and destruction. It is the most common inflammatory arthritis seen by healthcare professionals and affects around 1% of the UK population.
• It requires early and intensive treatment to reduce the risk of significant morbidity.
• The peak age of onset in the UK is between 30 and 50 years of age.
• If left untreated (or sub-optimally treated) it can significantly decrease quality of life, have an impact on employment, increase the likelihood of joint replacement surgery and increase overall mortality risk.
• The diagnosis is typically a clinical one, with further investigations such as imaging providing prognostic rather than diagnostic information.
• The human leukocyte antigens HLA DR4 and DR1 are more common in patients with RA, especially in severe disease.
• Smoking appears to be an important risk factor, with other possible environmental triggers being obesity, diabetes and the presence of rheumatoid factor (RF) or anti-citrullinated protein antibodies in the blood.
• Patients typically present with a history of bilateral, symmetrical pain and swelling of the small joints of the hands and feet that they have been experiencing for several weeks, often with associated morning joint stiffness and sometimes with joint redness and reduced function.
• Once a clinical diagnosis has been made, several laboratory tests help to determine prognosis, including erythrocyte sedimentation rate or C-reactive protein; however, up to 40% of patients with RA may have normal levels. RF is positive in about 60% to 70% of patients and the higher the value, the worse the prognosis and the greater the need for aggressive treatment.
• Imaging tests may not be critical, but baseline X-rays of the hands and feet are often helpful in confirming the diagnosis and determining the disease severity.
• UK guidelines do not currently recommend ultrasound for the routine monitoring of disease activity in adults with RA.
• NICE recommends that early involvement of secondary care is vital in both establishing the diagnosis and starting disease-modifying anti-rheumatic drugs (DMARDs) as soon as possible.
• Patients with low level disease at presentation are usually started on a single conventional synthetic DMARD and NICE recommends first-line hydroxychloroquine treatment here.
• For more moderate-to-severe RA at presentation (such as evidence of erosive joint destruction on X-ray), more aggressive treatment is required, and methotrexate monotherapy is the initial treatment of choice in these patients.
• If the patient does not respond, or has an inadequate response to methotrexate monotherapy, a specialist may add a biological agent to methotrexate.
• RA patients treated aggressively and early in the course of the disease typically have a good prognosis, with most patients achieving good disease control long-term, although flares of disease are common, even in patients well controlled with DMARDS.
• Untreated RA is associated with increased premature mortality, most commonly from coronary artery disease. Approximately one in three people with RA have to stop work because of its impact within two years of disease onset, and this number increases over time.