Successful treatment of a mesangial proliferative glomerulonephritis with interstitial nephritis associated with Castleman's disease by an anti-interleukin-6 receptor antibody (tocilizumab).

We report a case of mesangial proliferative glomerulonephritis with interstitial nephritis associated with multicentric Castleman's disease (MCD) successfully treated with an anti-interleukin-6 receptor antibody (tocilizumab). This mesangial proliferative glomerulonephritis with interstitial nephritis was resistant to methylprednisolone treatment; however, it was markedly improved with tocilizumab, which was administered intravenously at a dose of 8 mg/kg every 2 weeks. These results suggest that tocilizumab is effective for the treatment of mesangial proliferative glomerulonephritis with interstitial nephritis associated with MCD.