Tocilizumab, a Humanized Anti-interleukin-6 Receptor Antibody, Induces Hepatic Iron Overload in a Susceptible Patient

A 75-year-old woman visited to our hospital with liver dysfunction. The patient's liver function was normal. She had been treated with tocilizumab for rheumatoid arthritis for two years. One year after initiation of tocilizumab treatment, liver dysfunction was observed. Serum ceruloplasmin concentration was low. We diagnosed hepatic iron overload because of a high ferritin concentration and a liver biopsy. The cessation of tocilizumab and phlebotomy improved the liver function. We believe that tocilizumab induced iron accumulation. We should be aware of the possibility that tocilizumab induces iron overload in susceptible patients and monitor iron status in patients treated with tocilizumab.