Tocilizumab for AA Amyloidosis after Treatment of Multicentric Castleman Disease with Steroids, Chemotherapy and Rituximab for Over 20 Years.

We herein report the long-term outcome (30 years) of a human immunodeticiency virus- and human herpesvirus 8-negative Japanese man who was diagnosed to have multicentric Castleman disease (MCD) of the plasmacytic type after investigation of generalized lymphadenopathy at 34 of age in 1983. He received chemotherapy based on lymphoma regimens (combinations of prednisolone, vincristine, vindesine, cyclophosphamide, etoposide, melphalan, and ranimustine, etc.) for over 20 years. Although the systemic lymphadenopathy resolved, AA amyloidosis-related nephropathy occurred, with a serum creatinine (Cre) level of 0.9 mg/dL and urinary protein excretion (UP) of 7.5 g daily. Rituximab was started, but Cre increased to 2.6 mg/dL in 2010 and UP was unchanged. Therefore, treatment with tocilizmab was started. As a result, his hypergammaglobulinemia was well controlled, C-reactive protein became normal, UP decreased to 3.5 g daily, and Cre remained at 2.5 mg/dL in 2013. When AA amyloid nephropathy occurred after long-term chemotherapy, lituximab could not control it, but tocilizmab stopped the progression of nephropathy. This case suggests that MCD and AA amyloidosis may both have a close relationship to the overproduction of interleukin-6.