Therapeutic Benefits of Tocilizumab Vary in Different Organs of a Patient with AA Amyloidosis

Abstract EN

Systemic reactive AA amyloidosis is a life-threatening complication of chronic inflammatory diseases.

Anti-interleukin-6 receptor, tocilizumab (TCZ), has been shown to improve clinical symptoms of patients with AA amyloidosis, accompanied with regression of the amyloid deposition.

We report a case of AA amyloidosis evaluated by histology of multiple organs before and after TCZ treatment.

A woman in her 60s with rheumatoid arthritis was referred to our hospital because of cardiac and renal dysfunction.

A gastric and renal biopsy revealed the deposition of AA amyloid, and echocardiography revealed concentric left ventricular hypertrophy.

Her estimated glomerular filtration rate was decreased to 8.6 mL/min/1.73 m2, and B-type natriuretic peptide, C-reactive protein, and serum amyloid A protein were significantly elevated.

TCZ treatments markedly decreased her serum amyloid A protein and C-reactive protein levels, but hemodialysis was required 1 year later.

Endoscopic gastric rebiopsy 3 years after initiation of TCZ treatments revealed the regression of amyloid deposition and echocardiography revealed improvement of her left ventricular hypertrophy.

However, a renal rebiopsy revealed that the amyloid deposition had not regressed.

In conclusion, these observations suggest that the therapeutic effects of TCZ can vary among organs in patients with AA amyloidosis.