TOPLINE:

An individual patient data meta-analysis of two randomized trials involving treatment-naive patients with early rheumatoid arthritis (RA) found that a hand-dominant joint involvement pattern was associated with a modestly better response to both conventional synthetic and biologic disease-modifying antirheumatic drugs (csDMARDs and bDMARDs, respectively), whereas a polyarticular joint involvement pattern predicted a worse response.

METHODOLOGY:

• Researchers conducted an individual patient data meta-analysis of two randomized controlled trials involving 1250 treatment-naive patients with early RA to investigate the association between joint involvement pattern subgroups and treatment responses to csDMARDs and bDMARDs.
• Participants were assigned to the following four joint involvement pattern subgroups on the basis of baseline clinical characteristics, primarily joint involvement in the 66/68 joint scheme: arthritis of the feet, oligoarticular disease, arthritis of the hands, and polyarthritis.
• Across the studies, patients were randomly assigned to receive methotrexate-based regimens — methotrexate alone or with glucocorticoids, csDMARDs, or bDMARDs in various combinations.
• Treatment outcomes were measured using the longitudinal Clinical Disease Activity Index (CDAI) and other disease activity indices through week 48.

TAKEAWAY:

• Patients with arthritis of the hands exhibited better CDAI scores after treatment than those in the other three subgroups (beta-coefficient, -1.4; P = .0016), whereas those with polyarthritis showed worse CDAI scores after treatment (beta-coefficient, 0.95; P = .035).
• Arthritis of the hands was also associated after treatment with a better disease activity score in 28 joints using C-reactive protein (beta-coefficient, -0.18; P = .0028), a higher likelihood of achieving CDAI remission (odds ratio [OR], 1.7; P = .0054), and a higher likelihood of achieving at least a 50% improvement in CDAI scores (OR, 1.6; P = .0074).
• Female sex was associated with worse CDAI scores (beta-coefficient, 1.2; P = .0031); however, anti-citrullinated protein antibodies did not show a significant association with CDAI scores after treatment (beta-coefficient, 0.19; P = .67).
• When compared across treatment types, csDMARDs and bDMARDs were similarly effective or ineffective across the joint involvement pattern subgroups.

IN PRACTICE:

“Our findings encourage future studies to test whether baseline [joint involvement pattern] subgrouping adds prognostic value beyond established predictors and whether it can inform risk stratification and monitoring before considering any role in guiding treatment intensity,” the authors of the study wrote.

SOURCE:

The study was led by Yasuo Nagafuchi, MD, PhD, Department of Rheumatology, Leiden University Medical Center, Leiden, Netherlands. It was published online on March 7, 2026, in Annals of the Rheumatic Diseases.

LIMITATIONS:

The post hoc nature of the analysis could have introduced potential biases. Assignment of joint involvement pattern subgroups required baseline clinical information, limiting clinical applicability. Complete clinical data were not available for every patient at baseline or at each visit, which may have affected the accuracy of findings.

DISCLOSURES:

The study received support from SPIDERR-EU from the Horizon Europe programme, SPIDERR-NL from ZonMW Open Competitie, ZonMW Klinische Fellow, and SQUEEZE from the Horizon Europe programme. Several authors reported receiving research grants, institutional support for educational programs, speaker fees and honoraria (personal or to institutions), consultancy or advisory fees, and payments for lectures from pharmaceutical companies, as well as contracts (personal or institutional), participation on data safety or advisory boards, and leadership roles in industry-funded initiatives.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.