Pulmonary artery aneurysm and CNS parenchymal involvement, along with diabetes mellitus and malignancy, were associated with increased mortality in a Brazilian cohort of Behçet's syndrome patients, with an overall mortality rate of 2.6% over 25 years.
Key Findings
Results
Overall mortality in this Brazilian non-endemic cohort of Behçet's syndrome patients was low at 2.6% over the 25-year study period.
303 adult patients were included, diagnosed with BS and followed at a tertiary referral center in São Paulo, Brazil, between January 2000 and December 2024.
Eight deaths occurred during the study period out of 303 patients (2.6%).
Median follow-up was 117 months (IQR 55-184).
61.6% of patients were female.
162 patients (53.4%) were lost to follow-up during the study period.
Results
Pulmonary artery aneurysm was associated with the highest risk of mortality among all factors examined.
Hazard ratio for pulmonary artery aneurysm was 28.44 (95% CI 3.32-243.52; p = 0.002).
This was identified through unadjusted Cox proportional hazards modeling.
Given only 8 deaths occurred, analyses were exploratory and unadjusted only.
This finding is consistent with mortality patterns reported from endemic regions where vascular involvement is a known driver of death.
Results
Central nervous system (CNS) parenchymal involvement was associated with significantly increased mortality.
Hazard ratio for CNS parenchymal involvement was 6.81 (95% CI 1.65-28.06; p = 0.008).
This was identified via unadjusted Cox proportional hazards regression.
Neurological involvement has been consistently linked to mortality in endemic-region studies, and this finding extends that observation to a non-endemic Brazilian population.
Results
Malignancy was associated with increased mortality in Behçet's syndrome patients.
Hazard ratio for malignancy was 8.81 (95% CI 2.02-38.50; p = 0.004).
This was among the stronger associations observed in the unadjusted analysis.
Analysis was limited by the small number of death events (n = 8), precluding adjusted multivariate modeling.
Results
Diabetes mellitus was associated with increased mortality in this Behçet's syndrome cohort.
Hazard ratio for diabetes mellitus was 6.72 (95% CI 1.67-27.03; p = 0.007).
Diabetes mellitus is a comorbidity rather than a disease-specific manifestation of BS.
Its association with mortality highlights the potential role of comorbid conditions alongside BS-specific organ involvement in determining outcomes.
Background
Data from non-endemic countries on Behçet's syndrome mortality remain limited, and this study represents one of the largest Brazilian cohorts examined over a 25-year period.
The study enrolled 303 adult patients, making it a large cohort for a non-endemic region.
Mortality research in BS has been predominantly conducted in endemic regions such as Turkey, Iran, and East Asia.
The retrospective design and high rate of loss to follow-up (53.4%) are acknowledged limitations.
Only exploratory unadjusted analyses could be performed due to the limited number of deaths (n = 8).
What This Means
This research suggests that Behçet's syndrome (BS), a rare inflammatory disease, has a relatively low death rate in Brazil — a country where the disease is uncommon — with only about 2.6% of patients (8 out of 303) dying over a 25-year follow-up period. The study tracked patients at a major referral hospital in São Paulo from 2000 to 2024, making it one of the largest and longest studies of BS mortality conducted outside the regions where the disease is most common, such as Turkey and other parts of the Middle East and Asia.
Despite the low overall mortality, the study identified several factors linked to a higher risk of death. Patients who developed a pulmonary artery aneurysm (a dangerous bulging of a blood vessel in the lungs) had dramatically elevated mortality risk — nearly 28 times higher than those without it. Patients with direct brain or spinal cord involvement from BS, cancer, or diabetes also had roughly 7–9 times higher mortality risk. These findings are exploratory because so few deaths occurred, meaning they cannot be fully adjusted for other influencing factors, but they align with what has been found in studies from regions where BS is more prevalent.
This research suggests that even in non-endemic populations, certain serious complications of Behçet's syndrome — particularly those affecting blood vessels and the nervous system — carry significant mortality risk and warrant close monitoring and aggressive treatment. The high rate of patients lost to follow-up (over half) is a notable limitation and points to challenges in managing a rare disease in a large country, which may also mean the true mortality rate is underestimated.
Aquino M, Bayeh B, Ejnisman C, Specian F, Macedo R, de Araujo P, et al.. (2026). Mortality in Behçet's Syndrome in a non-endemic population: a 25-year cohort study.. Immunologic research. https://doi.org/10.1007/s12026-026-09832-9