Renal AA Amyloidosis in Ankylosing Spondylitis: A Case Report

Ankylosing spondylitis (AS) is a chronic inflammatory joint disease of seronegative spondyloarthropathies (SpA). Secondary amyloid A amyloidosis (Amyloidosis AA) is an uncommon complication of ankylosing spondylitis (AS). Amyloidosis AA is a systemic disease characterized by amyloid deposition in many organs including kidneys. An amyloid fibril formation starts with inappropriate folding of amyloidogenic precursor proteins. The amyloid fibrils have a typical appearance on light microscope that could be easily identified. The classification of secondary amyloidosis is based on the precursor proteins that form amyloid fibrils along with systemic and local distribution of amyloid deposition. Renal involvement is most frequent in systemic amyloidosis. The clinical manifestation of renal amyloidosis differs depending on the type of amyloid protein with the location and amount of amyloid deposition. The treatment of amyloidosis should be focused on managing symptoms and stabilizing amyloid protein.