Tocilizumab improves gross hematuria in an adult patient with AA amyloidosis of the urinary bladder secondary to juvenile idiopathic arthritis

Abstract

    A 25-year-old woman with 11-year history of juvenile rheumatoid arthritis was admitted to our hospital due to pericardial and bilateral pleural effusion. Prednisolone 1mg/kg/day improved these symptoms and were gradually tapered. However, she developed gross hematuria that induced severe anemia required transfusion during the hospitalization. Biopsy specimens of the urinary bladder revealed amyloidosis and immunohistochemical staining of the specimens defined the process as amyloid AA. The amyloid deposits were also found in the kidney and heart. Tocilizumab, a humanized anti-interleukin-6 receptor antibody, was started at a dose of 8mg/kg every 4 weeks. Subsequently, gross hematuria disappeared quickly. Although AA amyloidosis of the gastrointestinal tract, kidney, and myocardium has already been reported to be improved by tocilizumab, this is the first report on improvement of AA amyloidosis of urinary bladder presenting gross hematuria by tocilizumab.