PO:36:245 | Uncovering clinical and demographic differences in major organ involvement versus benign Behçet’s disease: insights from a single-centre study

Federica Di Cianni¹, Antonello Sulis¹, Maria Laura Manca², Rosaria Talarico¹, Marta Mosca¹. | ¹Rheumatology Unit, University of Pisa, Pisa, Italy; ²Department of Clinical and Experimental Medicine and Department of Mathematics, University of Pisa, Pisa, Italy.

Background. Behçet’s disease (BD) is a rare chronic inflammatory disease with a multi-systemic clinical presentation. Mucosal ulcerations and skin lesions are the most common features, typically indicating a benign disease course. In contrast, major organ involvement (MOI) defines a severe disease due to the organ-threatening potential. Patients with MOI often require immunosuppressive treatment to achieve sustained remission and prevent organ damage. Identifying factors associated with the development of a MOI subset is crucial for understanding disease progression and guiding therapeutic strategies. The aim of this analysis was to describe and compare the clinical and demographic characteristics of patients with MOI BD and benign subset.

Materials and Methods. We retrospectively analyzed 186 BD patients with a minimum of 5 -year follow-up. Patients were classified into the MOI subset if they had a history of ocular, vascular or neurological involvement; those without MOI were classified as having benign disease. Descriptive statistics was performed (mean ± standard deviation, median with interquartile range). Categorical variables were compared using Chi-square test or Fisher's exact test when appropriate. Continuous variables were compared using Student's t-test for normally distributed data or Mann-Whitney U test for non-parametric data. Statistical significance was set at p < 0.05.

Results. The benign group included 80 patients (43.2%) while the MOI group consisted of 105 patients (56.8%). In both groups patients were mainly females (67.5% in benign group versus 64.8% in MOI group). The mean age at disease onset was 31.2 years (median:35) for benign group and 28.1 years (median:30) for MOI group, whereas the mean age at diagnosis was 38.1 years (median: 39) and 37.3 years (median: 38), respectively. The median diagnostic delay amounted to 3 years in benign group and 5 years in MOI group. However, no statistically significant differences were found regarding gender and age distribution. Oral ulcers (98.8%), genital ulcers (68.8%) and pseudo-folliculitis (46.3%) were the most common cumulative clinical features in patients with benign disease, while MOI patients most frequently showed ocular manifestations (74%), followed by neurological (21%) and vascular (24%) lesions. Differences in prevalence of arthritis, erythema nodosum and gastrointestinal involvement were less pronounced among the two groups.

Conclusions. This monocentric cohort highlights distinct organ involvements in patients with benign and MOI BD subset, consistent with previous evidence. Patients with MOI BD showed earlier disease onset and longer diagnostic delay compared to benign patients. These findings suggest that in addition to MOI, also prolonged disease duration before diagnosis may contribute to disease severity. Further studies including also etiopathogenetic variables are needed to identify potential predictive factors of severe disease, aiming to facilitate earlier diagnosis and timely treatment to reduce organ damage and clinical burden.