Psoriatic arthritis is biologically heterogeneous, and validated predictive biomarkers for treatment selection are lacking. In an oral abstract presentation on Wednesday 3rd June at the 2026 EULAR Congress in London, there was an overview of moving from disease-centred to tissue-centred care, with results from a real-world proof-of-concept study comparing the clinical effectiveness of a biopsy-driven therapeutic strategy with a standard approach based solely on clinical and laboratory evaluation in 35 patients with psoriatic arthritis. Synovial samples were evaluated and classified into three pathotypes: myeloid, lympho-myeloid, and pauci-immune; 15 patients had a myeloid CD117-positive synovial pathotype identified on immunohistochemistry, and received a biopsy-driven strategy with biologics directed against IL-17, IL-23, or TNF. A matched control group of 20 patients was treated with a biologic based on standard clinical judgement without biopsy guidance.
The primary clinical endpoint of low disease activity or remission was achieved in 68% of patients receiving biopsy-driven treatment, compared with only 45% in the control group. In those with a myeloid CD117-positive pathotype, mean reduction in DAPSA at 6 months was markedly greater with IL-17 and -23 inhibitors compared with TNF inhibitors. Furthermore, the quantitative burden of synovial inflammation was shown to influence treatment response. These findings suggest a biological basis for differential response to therapy, and highlight the central role of the IL-17/23 axis in this subgroup.
“This real-life proof-of-concept study shows that a synovial biopsy-driven therapeutic strategy is associated with improved clinical outcomes compared with standard clinical management in PsA,” said Simone Parisi, presenting the findings on behalf of the research team in Turin, Italy. “These findings support a tissue-centred precision medicine approach in psoriatic arthritis, and warrant confirmation in larger prospective studies.”
Another novel therapeutic strategy was presented by Lihi Eder, focusing on the role of diet – an area where current knowledge is limited. DIPSA is a multicentre randomised controlled trial in 92 patients with active psoriatic arthritis and a mean body mass index of 33. The study was designed to evaluate whether personalised dietary interventions can improve clinical outcomes compared to standard of care. Participants were randomised to either a Mediterranean diet focused on healthy food composition enriched with olive oils and nuts, or a low-calorie diet targeting weight reduction and lowered blood pressure – both with in-person consultatons and telephone support with a dietitian – versus a standard-of-care control arm receiving general printed materials with non-personalised dietary advice.
All groups experienced modest and statistically significant weight loss compared to baseline by Week 12, with no significant difference between the different approaches – but the primary endpoint was change in DAPSA. Here, there were significant reductions in DAPSA score compared from baseline to Week in the low calorie and control groups, and by Week 24 all groups showed improvement, with no significant differences between-groups. Improvements in pain, fatigue, and tender joints were observed across all arms.
Importantly, the magnitude of weight loss was significantly associated with improvement in clinical outcomes, independent of the dietary intervention.
“These findings suggest that weight loss – independent of the approach used – may be an effective adjunctive strategy for reducing residual disease activity in overweight and obese patients with psoriatic arthritis”, said Lihi Eder, presenting on behalf of colleagues in Canada and the United States.
Source
Ditto MC, et al. From disease-centred to tissue-centred care in psoriatic arthritis: clinical impact of synovial biopsy–driven therapeutic stratification. Presented at EULAR 2026; OP0071. Ann Rheum Dis 2026; DOI: 10.1136/annrheumdis-2026-eular.B.1257.
Eder L, et al. Dietary interventions in Psoriatic Arthritis (DIPSA): A Randomized controlled clinical trial. Presented at EULAR 2026; OP0070. Ann Rheum Dis 2026; DOI: 10.1136/annrheumdis-2026-eular.B.545.
References
1. Gwinnutt JM, et al. 2021 EULAR recommendations regarding lifestyle behaviours and work participation to prevent progression of rheumatic and musculoskeletal diseases. Ann Rheum Dis 2023;82(1):48–56. DOI: 10.1136/annrheumdis-2021-222020.
About EULAR
EULAR is the European umbrella organisation representing scientific societies, health professional associations and organisations for people with rheumatic and musculoskeletal diseases (RMDs). EULAR aims to reduce the impact of RMDs on individuals and society, as well as improve RMD treatments, prevention, and rehabilitation. To this end, EULAR fosters excellence in rheumatology education and research, promotes the translation of research advances into daily care, and advocates for the recognition of the needs of those living with RMDs by EU institutions.
Contact
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Notes to Editors