136. A DECLINING TREND IN FREQUENCY OF SECONDARY AMYLOIDOSIS IN BEHÇET’S SYNDROME

Background: A decline in the frequency of AA amyloidosis secondary to rheumatoid arthritis and infectious diseases has been reported. We have previously found 14 (0.35%) among 4000 BS patients registered between 1976-2001. We aimed to determine the trend in the frequency of AA amyloidosis in BS patients in addition to summarize clinical characteristics and outcomes of these patients.

Methods: Among our 9410 BS patients, a chart review revealed 27 (0.29%) patients with amyloidosis. We noted demographic characteristics, BS manifestations, age at BS and AA amyloidosis diagnosis, and treatment modalities of these patients. Our endpoints were death and end stage renal disease (ESRD) requiring renal replacement therapy. The prevalence of AA amyloidosis was calculated separately for two periods (patients registered between 1976-2000 and 2000-2017).

Results: We identified 24 AA amyloidosis among the 3820 patients in the earlier cohort and 3 additional AA amyloidosis among the 5590 patients in the recent cohort. The prevalence of AA amyloidosis has been declined from 0.62% to 0.054% in the recent cohort. Twenty-two (82%) of the patients with AA amyloidosis had major organ involvement (vascular involvement in 15, eye involvement in 13 and neurologic involvement in 2). Five (18%) of 27 patients had only mucocutaneous involvement. Fourteen (52%) patients died after a median follow up of 3 (IQR: 1-8.75) years, 3 were lost to follow-up just after AA amyloidosis diagnosis and 10 (37%) are still alive after a median follow up of 16 (IQR: 10-23) years. The reasons for death were infections in 5, related to ESRD in 5, subarachnoid hemorrhage, gastric adenocarcinoma, liver cirrhosis probably associated with amyloidosis and iatrogenic bowel perforation in 1 patient each. 10 (71%) of 14 patients had developed ESRD before their deaths. Overall, 15/27 patients developed ESRD after a median follow- up of 3.5 (IQR: 1.25-6.5) year after AA amyloidosis diagnosis. 5 of them had renal transplantation, all but 1 are still alive after 3, 4, 6, and 12 years. The last one died 11 years after transplantation due to subarachnoid hemorrhage as explained above.

Conclusion: AA amyloidosis appears to be a rare, but fatal complication of BS. Around 50% of patients died after a median follow-up of 3 years after AA amyloidosis. This study showed a decreasing trend of AA amyloidosis due to BS similar to that observed in other inflammatory and infectious causes. The shorter follow-up duration may be contributing for the lower prevalence of AA amyloidosis in the recent cohort.

Disclosures: None