Renal amyloidosis in Behçet's disease: clinicopathologic features of 8 cases

Behçet's disease (BD) is a rare inflammatory disorder with variable articular and systemic manifestations. Amyloidosis is an uncommon complication of BD. The aim of this study is to present clinicopathological characteristics and outcome of 8 patients with renal amyloidosis secondary to BD.

A total of 220 cases of secondary-type renal amyloidosis diagnosed over 26-year period (1981-2007) in a single institution via needle biopsy were reviewed retrospectively, and accompanying BD was found in ten of them. Clinical and follow-up information of the patients was gathered from hospital records and computer-based data system. Two cases were excluded from the study due to another concomitant preamyloidotic condition. Biopsy slides of remaining 8 cases were culled from the archives and re-examined. Extent and pattern of renal amyloid deposition were explored. Amyloid typing was accomplished via immunohistochemistry. Factors acting on outcome and renal survival were explored.

Patients were all male (age range 27-56). Duration of BD before diagnosis of amyloidosis varied from 24 to 192 months, and mean follow-up period was 89 months. Nephrotic syndrome was the most common presentation. Immunohistochemical typing revealed AA-amyloid in all cases. Two cases showed glomerular-dominant, one case vascular-dominant amyloid deposition, and rest were codominant glomerular and vascular, except one that was indeterminate. Patients were treated with steroids and/or different immunosuppressives, three progressed to end-stage kidney failure.

Behçet's disease is one of the rare diseases that lead to AA amyloidosis. Morphology of renal amyloidosis due to BD has diversities in terms of differential amyloid deposition in renal compartments. Patients follow variable clinical courses accordingly.