Sustained remission of multicentric Castleman disease in children treated with tocilizumab, an anti-interleukin-6 receptor antibody.

Multicentric Castleman Disease (MCD) is an idiopathic lymphoproliferative disorder, reported exceptionally in children and generally believed to be an autoinflammatory disease resulting in an increase of interleukin-6 secretion. Previous studies in adult patients suggested a beneficial role of the anti-interleukin-6 receptor antibody tocilizumab on the clinical and biologic disease manifestations of MCD. Here, we describe the efficacy and safety of tocilizumab in two children with MCD, which was diagnosed on the basis of clinical and histologic findings. In both cases, tocilizumab was administered intravenously at a dose of 8 mg/kg every 2 weeks. The tocilizumab treatment alleviated fever and restored growth rate in both patients. The patients' hypergammaglobulinemia, high C-reactive protein, and high erythrocyte sedimentation rates normalized simultaneously. Nevertheless, splenomegaly persisted in the first patient, and a secondary hepatic node appeared in the second patient. The side effects, essentially sustained thrombocytopenia, were mild in both cases. For the first patient, following an initial 10-month period, the interval between infusions was increased. This patient benefited from sustained remission for a period of 3 years. Tocilizumab was effective and safe in these two children with MCD.