Incidence of organ involvement in Behcet’s disease: a historical cohort study

Abstract Objective: The objective of this study was to assess the incidence of BD-related serious organ involvements in a sizeable cohort of patients with Behcet’s disease. Methods: In a retrospective cohort study 1166 patients with Behcet’s disease whose first visit to BD clinic was registered between April 1995 and March 2001 were enrolled and followed up until March 2012 for ocular, vascular, joint, Central Nervous System (CNS), and epididymis involvement. Incidence density and cumulative incidence of different organ lesions from the disease onset were estimated. Results: Age at disease onset was 25.1 ±9.46 (mean ± SD) years and the male to female ratio was 1.34:1. The incidence density (per 100 person-year) of ocular involvement was 7.6 (CI 95%: 7.08 – 8.25), joint involvement was 1.32 (CI 95%: 1.13- 1.54), vascular involvement was 0.66 (CI 95%: 0.53-0.81), epididymitis/orchitis was 0.67 (CI 95%: 0.5-0.88) and CNS involvement was 0.14 (CI 95%:0.09-0.22). The incidence density of blindness was 1.63 per 100 person-year (CI 95%: 1.42-1.87). The cumulative incidence of different organ involvement 10 years after the onset of Behcet’s disease was 53.2% for ocular lesions, 6.4% for vascular lesions, 12.4% for joint lesions, and 6.4% for Epididymitis/Orchitis (in male patients). Conclusions: Ocular involvement occurred in almost half of the patients within the 10 years after disease onset. At a lower rate but not less important, other inflammatory organ involvement like vasculitis, arthritis, epididymitis and CNS involvement may occur in the BD patients.