PO:03:044 | Impact of Inflammatory Bowel Disease on Clinical Phenotype and Treatment Response in Patients with Psoriatic Arthritis

Maria Morrone¹, Maria Giannotta¹, Vincenzo Venerito¹, Greta Giulia Dipietrangelo¹, Stefano Stano¹, Florenzo Iannone¹, Giuseppe Lopalco¹ | ¹Department of Precision and Regenerative Medicine and Ionian Area DiMePRe-J University of Bari, Bari, Italy

Background. Patients with psoriatic arthritis (PsA) may present with concomitant inflammatory bowel disease (IBD), which can influence disease phenotype and therapeutic response. However, evidence regarding the impact of IBD on PsA management remains limited. Objectives. To assess whether concomitant IBD affects the clinical presentation and treatment response of PsA patients, through a comparison between matched cohorts with and without IBD.

Methods. A retrospective, observational study was conducted, including PsA patients with or without concomitant IBD, matched 1:1 for age, sex, and biologic DMARD (bDMARD) therapy. Baseline demographic and clinical data were collected, including BMI, disease duration, articular and extra-articular involvement, HLA-B27 status, and concomitant treatments. Disease activity was assessed using the Disease Activity index for Psoriatic Arthritis (DAPSA) at 6 and 12 months. DAPSA progression over time and its interaction with IBD status were analyzed using repeated measures ANOVA. Multivariate logistic regression analyses were performed to identify predictors of DAPSA low disease activity (LDA) and remission at 12 months.

Results. A total of 120 PsA patients were included (60 with concomitant IBD and 60 without). No significant differences were observed between groups in terms of age, sex, BMI, or disease duration. A higher prevalence of personal history of psoriasis was found in the PsA-only group (86.7% vs 66.7%, p=0.017). Disease subset (oligo/poly), axial involvement, and treatment distribution were comparable. TNF inhibitors were the most prescribed bDMARDs in both groups (95%). A significant reduction in DAPSA scores over time was observed in both groups (p<0.001). Although a trend towards a greater decrease in the PsA-only group was noted, the interaction between IBD status and time did not reach statistical significance (p=0.062). In the multivariate analysis, lower baseline DAPSA (aOR 0.93; 95% CI:0.89-0.97; p = 0.001) and lower BMI (aOR 0.90; 95% CI:0.81-1.00; p = 0.041) emerged as independent predictors of achieving low disease activity (LDA) or remission.

Conclusions. In this matched real-life cohort, concomitant IBD did not significantly affect clinical phenotype, disease activity trajectory, or treatment response in PsA patients receiving bDMARDs. Baseline disease activity and BMI emerged as the strongest independent predictors of achieving DAPSA low disease activity and remission at 12 months. These findings suggest that PsA patients with concomitant IBD can be effectively managed according to PsA-specific therapeutic targets, without necessarily requiring treatment adaptations solely based on the presence of IBD.