Frequency of AA amyloidosis has decreased in Behcet's syndrome: a retrospective study with long-term follow-up and a systematic review Amyloidosis in Behcet's syndrome

Objective A decline in the frequency of AA amyloidosis secondary to RA and infectious diseases has been reported. We aimed to determine the change in the frequency of AA amyloidosis in our Behcet's syndrome (BS) patients and to summarize the clinical characteristics of and outcomes for our patients, and also those identified by a systematic review. Methods We identified patients with amyloidosis in our BS cohort (as well as their clinical and laboratory features, treatment, and outcome) through a chart review. The primary end points were end-stage renal disease and death. The prevalence of AA amyloidosis was estimated separately for patients registered during 1976-2000 and those registered during 2001-2017, in order to determine whether there was any change in the frequency. We searched PubMed and EMBASE for reports on BS patients with AA amyloidosis. Risk of bias was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool. Results The prevalence of AA amyloidosis was 0.62% (24/3820) in the earlier cohort and declined to 0.054% (3/5590) in the recent cohort. The systematic review revealed 82 cases in 42 publications. The main features of patients were male predominance and a high frequency of vascular involvement. One-third of patients died within 6 months after diagnosis of amyloidosis. Conclusion The frequency of AA amyloidosis has decreased in patients with BS, which is similar to the decrease observed for AA amyloidosis due to other inflammatory and infectious causes. However, AA amyloidosis is a rare, but potentially fatal complication of BS.