Evidence-based treatment guidelines for iMCD.³¹ IL-6 blockade, including siltuximab and secondarily tocilizumab, in combination with high-dose steroids is recommended as first-line therapy in international treatment guidelines for severe iMCD. Cytotoxic chemotherapy is recommended as second-line therapy in severe patients, while rituximab in combination with steroid therapy is recommended second-line in nonsevere patients. Retrospective validation supports these guidelines and is supportive against steroid monotherapy.³²