Ankylosing spondylitis-related secondary amyloidosis responded well to etanercept: a report of three patients.

Secondary (AA) amyloidosis is one of the most significant complications of ankylosing spondylitis (AS) that frequently leads to proteinuria and renal dysfunction. Anti-tumor necrosis factor alpha (anti-TNF) agents are promising in inducing clinical remission by suppressing systemic inflammation in AA amyloidosis. We report three cases with AS-related AA amyloidosis that responded well to etanercept therapy. Despite treatment with disease modifying anti-rheumatic drugs, all three patients had active AS, marked proteinuria, impaired renal function, and low serum albumin level. During 1-year treatment with etanercept, all patients experienced gradual improvement in all of these parameters.