The efficacy of tocilizumab in a patient with pulmonary arterial hypertension associated with Castleman's disease.

Castleman's disease is a highly heterogeneous clinical-pathological entity that belongs to the lymphoproliferative disorders and is associated with pulmonary arterial hypertension (PAH) in some patients. It is linked to excessive immune stimulation by interleukin-6 (IL-6), which is also involved in the pathogenesis of PAH. A 31-year-old woman with Castleman's disease demonstrated PAH characterized by severe right heart failure. Since she was resistant to various conventional therapies including steroids, prostacyclins, bosentan, and sildenafil, tocilizumab (anti-IL-6 receptor antibody) therapy was started. Her clinical course was followed for 6 months, with significant improvement without any adverse effect. This is the first reported case of use of tocilizumab in addition to steroids and conventional PAH therapy in a patient with PAH associated with Castleman's disease.