Rheumatoid Arthritis: Diagnosis and Management Guide

Rheumatoid arthritis is diagnosed clinically, by finding swollen joints and reading rheumatoid factor and anti-CCP (anti-cyclic citrullinated peptide) antibodies in that context, and it is managed by treating early to a measured target. Dr. Sajal Ajmani, HOD – Rheumatology, Manipal Hospital, Dwarka, New Delhi, India, presented an approach that rests on three disciplines: diagnose early, measure disease activity at every visit, and escalate therapy on a fixed timetable until remission is reached.

Dr. Sajal Ajmani, then Consultant - Rheumatology at Manipal Hospital, New Delhi, India, and now HOD – Rheumatology at Manipal Hospital, Dwarka, New Delhi, India, took international doctors through the diagnosis and management of rheumatoid arthritis in a Jivo Masterclass on Sunday 1 September 2024. This guide sets out the logic of his approach and the measurement framework that ties it together. Two companion articles go deeper: how rheumatoid arthritis is diagnosed, from the 2010 criteria to serology pitfalls, and the treat-to-target DMARD strategy, from methotrexate to biologics.

What rheumatoid arthritis is

Rheumatoid arthritis is a chronic autoimmune disease in which the immune system attacks the synovium, the thin membrane that lines the joints. The inflamed synovium thickens, produces fluid and, if left untreated, erodes cartilage and bone. The disease typically affects the small joints of the hands and feet on both sides of the body, and it is two to three times more common in women than in men.

Two features make it a priority for any physician who sees joint pain. First, it is common: it affects roughly 0.5 to 1% of adults worldwide. Second, the damage it causes is largely irreversible once erosions have formed, which is why the speed of diagnosis shapes the patient's lifetime outcome.

Why rheumatoid arthritis is a clinical diagnosis

The point Dr. Ajmani wanted every attendee to take away was that rheumatoid arthritis is a clinical diagnosis. A positive rheumatoid factor does not mean the patient has rheumatoid arthritis; the result has to be correlated with what the examining doctor finds in the joints. His summary of the diagnostic task was a clinical assessment of the swollen joints, read together with the anti-CCP and rheumatoid factor levels.

The reason is practical. Both antibodies turn up in infections and other conditions, and rheumatoid factor appears in a share of healthy older adults. A laboratory-led diagnosis therefore produces two kinds of error: patients labelled with a lifelong disease they do not have, and patients with genuine early synovitis dismissed because their serology is negative. The detailed scoring system, the diseases that mimic rheumatoid serology and the early forms of the disease are covered in the companion article on diagnosis.

Early rheumatoid arthritis: the window of opportunity

Dr. Ajmani described a period early in the course of the disease, known as early rheumatoid arthritis, during which the disease process can be altered and sustained drug-free remission becomes possible. Patients who had symptoms for less than 12 weeks when treatment began had the lowest rate of joint destruction and the highest chance of DMARD-free remission, meaning remission that holds even after disease-modifying antirheumatic drugs (DMARDs) are withdrawn.

This is the strongest argument for early referral. A patient treated within three months of the first symptoms has the best prospect of DMARD-free remission; once deformities have developed, the damage cannot be undone. For referring doctors, persistent swelling of more than one joint, particularly in the hands, justifies starting the diagnostic work-up at once rather than waiting to see whether it settles.

How rheumatoid arthritis disease activity is measured

Before discussing any drug, Dr. Ajmani explained how a patient with rheumatoid arthritis is monitored, because every treatment decision that follows depends on a number. Several formal disease activity indices exist, and he acknowledged that in routine clinics there is usually no time to calculate them. What he looks at in practice is four things: the number of swollen joints, the number of tender joints, the erythrocyte sedimentation rate (ESR, a blood marker of inflammation), and a general assessment, on a scale of 0 to 100, of how the patient is doing.

The 28-joint count

The joints examined are the shoulders, elbows, wrists, the metacarpophalangeal joints at the base of the fingers, the proximal interphalangeal joints in the middle of the fingers, and the knees. Counted on both sides, these make up the 28 joints used in the standard scores. Each is checked for tenderness and for swelling separately, because the two do not always move together.

DAS28 score and cut-offs

The Disease Activity Score in 28 joints (DAS28) combines the tender and swollen joint counts, the ESR or C-reactive protein (CRP, another blood marker of inflammation), and the patient's global assessment into one figure. Dr. Ajmani gave the threshold for the top of the scale: a DAS28 above 5.1 indicates high disease activity. At the other end, a score below 2.6 corresponds to remission. Between those points, a score of 3.2 or less is conventionally read as low disease activity and a score above 3.2 up to 5.1 as moderate activity.

SDAI and CDAI cut-offs

The Simplified Disease Activity Index (SDAI) avoids the logarithms of DAS28 and is a straightforward sum. The patient rates his or her own condition from 0 to 10, the doctor rates it from 0 to 10, and these two figures are added to the tender joint count, the swollen joint count and the CRP value. Dr. Ajmani gave the cut-offs:

• 3.3 or less: remission
• 11 or less: low disease activity
• 26 or less: moderate disease activity
• above 26, up to the maximum of 86: high disease activity

The Clinical Disease Activity Index (CDAI) is the same calculation without the CRP. Because it needs no blood result, it can be scored in the consultation itself, which makes it especially useful where laboratory turnaround is slow. Its conventional cut-offs are 2.8 or less for remission, 10 or less for low activity and 22 or less for moderate activity.

ACR20, ACR50 and the definition of remission

The American College of Rheumatology (ACR) response criteria describe improvement rather than status. ACR20 means a 20% improvement and ACR50 a 50% improvement; ACR70 completes the series. These measures are used mainly in clinical trials to compare drugs.

Remission itself has a strict definition. As Dr. Ajmani presented it, a patient is in remission when the tender joint count is one or zero, the swollen joint count is one or zero, the CRP is 1 mg/dL or less, and the patient rates his or her disease at one or less on a scale of 0 to 10 (two or less since the 2022 revision). This is the ACR/EULAR Boolean definition, and it is deliberately demanding: every element must be met at the same time.

The aim of treatment, in his words, is to achieve either low disease activity or total remission. That target is what the treatment ladder is built around.

Extra-articular manifestations: disease beyond the joints

Extra-articular manifestations are those that affect organs other than the joints. Answering a question put in French during the live session, Dr. Ajmani explained that such involvement is less common than joint disease, and severe forms affect a minority of patients, but it occurs and has to be recognised:

• Lungs: interstitial lung disease, a scarring and inflammatory process in the lung tissue.
• Eyes: scleritis, inflammation of the white outer coat of the eye, and dryness.
• Heart: very rarely, pericarditis and pericardial effusion, inflammation of the sac around the heart and fluid collecting within it.
• Kidneys: very rarely, glomerulonephritis and amyloidosis.
• Skin: vasculitis, inflammation of the small blood vessels.

For cardiac involvement in the form of pericarditis or pericardial effusion, his treatment is steroids plus methotrexate.

Each of these manifestations carries its own clinical weight. Interstitial lung disease is the most important for long-term survival and is assessed with high-resolution CT and lung function tests. Scleritis can threaten sight and needs prompt ophthalmology review, whereas dryness of the eyes and mouth reflects secondary Sjögren's syndrome. Amyloidosis in rheumatoid arthritis is the AA type, driven by years of uncontrolled inflammation, which makes it largely preventable through sustained disease control. Extra-articular disease is more common in patients with high-titre rheumatoid factor, long-standing disease and smoking.

Rheumatoid arthritis management: the treatment strategy in outline

Management follows the recommendations of EULAR, the European Alliance of Associations for Rheumatology, which Dr. Ajmani presented in their 2016 form and pointed attendees to the 2022 update. Disease-modifying therapy starts as soon as the diagnosis is made, methotrexate anchors the first strategy, and therapy is adjusted whenever the patient has not improved by three months or reached target by six months. The full ladder, including drug choice in pregnancy and liver disease, the role of poor prognostic factors and how therapy is tapered, is set out in the companion article on treat-to-target treatment.

Questions from the live session

Two questions were answered aloud: one on organ involvement beyond the joints, answered above, and one on the treatment of palindromic rheumatism. Several others were answered in the session chat. The audible exchanges are recorded on the masterclass Live Discussion page. More on Dr. Ajmani's practice is on his doctor profile, and related topics sit within Jivo Healthcare's rheumatology specialty hub.