Evaluation of major organ involvement risk and onset durations according to prognostic factors in behçet's disease

Aim: In Behçet's disease, mucocutaneous manifestations are the most commonly observed findings and often manifest early before systemic involvement in the majority of patients. Dermatologists play a significant role in the diagnosis and monitoring of Behçet's disease. Evaluating patients for signs of systemic involvement during follow-up is crucial, as it can facilitate early diagnosis and treatment of major organ involvement. While there are studies in the literature reporting average onset times for systemic involvement, there is a lack of research assessing these based on prognostic factors. This study aims to evaluate the risk of major organ involvement and the onset times based on prognostic factors such as gender and age at onset, with the intention of providing guidance for patient follow-up. Materials and Methods: The study included 1085 patients who were followed with a diagnosis of Behçet's disease at the Ankara University Faculty of Medicine Multidisciplinary Diagnosis and Treatment Unit between January 1999 and December 2022, meeting the International Criteria for Behçet's Disease (ICBD) and were followed for a minimum of 5 years after meeting the the criteria. Information related to patients' age, gender, age at completion of diagnostic criteria, major organ involvements, and the time elapsed from meeting the criteria to the onset of involvements were retrospectively reviewed. Major organ involvements were defined as ocular, vascular, neurological, and gastrointestinal system (GIS) involvements. Patients were categorized into subgroups based on gender and age at diagnosis; juvenile (≤16) adult (>16), ≤25/>25 and ≤40/>40. These subgroups were compared in terms of the frequency of major organ involvement within themselves and the duration from completing diagnostic criteria to major organ involvement. Results: Of the patients, 56.4%(n=612) were female, and 43.6%(n=473) were male. The mean age at diagnosis was 29.1±9 years, and the mean follow-up duration was 13.73±6.89 years. While 48% of the patients were followed with mucocutaneous involvement, at least one major organ involvement was present in 52%. All major organ involvements were significantly more common in male patients compared to female patients. The onset of ocular involvement occurred, on average, 4.6±6.6 years after diagnosis in female patients and 2.6±5.4 years in male patients. The onset of ocular involvement was significantly shorter in male patients. There was no statistically significant difference in the time to the onset of vascular, neurological, and gastrointestinal system involvements based on gender. When comparing the frequency of major organ involvement according to the age at diagnosis (before/after 16 years, 25 years, and 40 years), no significant difference was observed. In the group diagnosed after the age of 25, the onset of ocular and vascular involvements (mean 2.9±5.7 years and 3.3±6 years after diagnosis, respectively) was significantly shorter than in the group diagnosed before the age of 25 (mean 4.7±6.6 years and 6±5.8 years after diagnosis, respectively). Conclusions: In our study, in accordance with the literature, major organ involvement has been more frequently detected in male patients. However, demonstrating no significant difference in the frequency of major organ involvement between patients diagnosed after the age of 25 compared to those diagnosed at ≤25 years, but showing it to manifest earlier, indicates the importance of regular monitoring in this patients group as well. While the statistical significance of the longer duration in juvenile patients compared to adult patients may not be evident, it emphasizes the importance of ensuring that these patients remain engaged in follow-up and treatment. Generally, the majority of major organ involvements develop within the first 5 years after diagnosis, albeit the occurrence of such involvements in a few patients even 18 years before meeting diagnostic criteria and 31 years later, highlights the variable course of the disease from patient to patient and underscores the importance of long-term follow-up.