Rheumatoid Arthritis (RA)

What is rheumatoid arthritis?

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease that primarily attacks the synovium: the lining of joints. Unlike osteoarthritis (wear and tear), RA is driven by the immune system mistakenly attacking healthy joint tissue, causing inflammation that eventually damages cartilage and bone. RA affects about 1% of the global population and is 2–3 times more common in women. It most commonly begins between ages 30–60.

Blood tests for RA diagnosis and monitoring

Symptoms of RA

• Symmetrical joint swelling: both hands, both wrists (not one side like gout)
• Morning stiffness lasting more than 1 hour (key distinguishing feature from osteoarthritis)
• Warm, tender, swollen joints
• Fatigue and low-grade fever
• Small joints of hands and feet involved first
• Rheumatoid nodules: firm lumps under the skin near elbows
• Weight loss in active disease

DAS28: measuring disease activity

The Disease Activity Score (DAS28) is used to track RA severity and guide treatment. It combines joint counts, CRP or ESR, and the patient's own assessment of disease activity. Scores: <2.6 = remission; 2.6–3.2 = low disease activity; 3.2–5.1 = moderate; >5.1 = high activity.

Treatment overview

Questions to ask your doctor

• Are both my RF and anti-CCP positive?
• What is my DAS28 score?
• Should I start methotrexate?
• How often should I monitor my blood tests on DMARDs?
• Do I need hand X-rays to check for joint erosions?

References

The clinical information on this page is drawn from peer-reviewed sources indexed by the US National Library of Medicine. Links go to the source so you can read it yourself.

1. Erythrocyte Sedimentation Rate. In: StatPearls. Treasure Island (FL): StatPearls Publishing. NCBI Bookshelf NBK557485
2. Rheumatoid Factor. In: StatPearls. Treasure Island (FL): StatPearls Publishing. NCBI Bookshelf NBK532898

References

Sources cited on this page. PubMed links open the original abstract.

1. Scott DL, Wolfe F, Huizinga TW. Rheumatoid arthritis. Lancet. 2010;376(9746):1094–1108. PMID 20870100 · doi:10.1016/S0140-6736(10)60826-4

The 2010 ACR/EULAR classification criteria

Rheumatoid arthritis (RA) is classified (not diagnosed in isolation) using the 2010 ACR/EULAR criteria, which assign points across four domains. A score of 6 or more out of 10 is classified as definite RA:

• Joint involvement (0–5 points): 1 large joint = 0; 2–10 large joints = 1; 1–3 small joints = 2; 4–10 small joints = 3; more than 10 joints (including at least one small joint) = 5
• Serology (0–3 points): Negative RF and anti-CCP = 0; low positive RF or anti-CCP = 2; high positive RF or anti-CCP (above 3× ULN) = 3
• Acute phase reactants (0–1 point): Normal CRP and ESR = 0; abnormal CRP or ESR = 1
• Duration of symptoms (0–1 point): Less than 6 weeks = 0; 6 weeks or more = 1

These criteria are designed to capture early RA before irreversible joint damage has occurred – enabling earlier treatment and better outcomes. A patient who does not meet criteria may still be treated if clinical suspicion is high.

Monitoring disease activity – DAS28 and treat-to-target

The Disease Activity Score 28 (DAS28) is the standard composite measure of RA activity used in UK rheumatology practice to guide treatment decisions:

• DAS28 above 5.1 = high disease activity (sustained high activity → step up treatment)
• DAS28 3.2–5.1 = moderate disease activity
• DAS28 2.6–3.2 = low disease activity (the minimum acceptable clinical target)
• DAS28 below 2.6 = remission (the aspirational target)

DAS28 incorporates: count of tender joints (0–28), count of swollen joints (0–28), ESR or CRP, and the patient's visual analogue scale global health score. The "treat-to-target" (T2T) strategy – adjusting therapy every 1–3 months until DAS28 target is achieved – is the NICE-recommended approach and produces significantly better joint outcomes than reactive treatment.

DMARD step-up – from methotrexate to biologics

• Step 1: Methotrexate (first-line DMARD, 15–25 mg weekly, with folic acid 5 mg once weekly). FBC and LFTs monitored 4-weekly initially then 3-monthly. Contraindicated in significant liver disease, renal impairment (eGFR below 30), or planned pregnancy.
• Step 2: Combination csDMARDs – add hydroxychloroquine and/or sulfasalazine if methotrexate alone is insufficient after 3–6 months.
• Step 3 (biologic DMARDs): If DAS28 remains above 5.1 on maximally tolerated csDMARD therapy, NICE recommends a biologic: TNF inhibitor (adalimumab, etanercept, certolizumab) or IL-6 receptor inhibitor (tocilizumab, sarilumab), depending on comorbidities. Rituximab (B cell depletion) is used in seronegative RA or where TNF inhibitors fail or are contraindicated (prior lymphoma, demyelinating disease).
• JAK inhibitors (tofacitinib, baricitinib, upadacitinib): Oral targeted synthetic DMARDs – effective as biologic alternatives but require prescriber awareness of cardiovascular and thromboembolic risk signals from post-marketing surveillance.