Cyclosporine for the treatment of multisystem inflammatory syndrome in children with coronary artery aneurysms.

Multisystem inflammatory syndrome in children (MIS-C) is a newly described syndrome related to the COVID-19, resembling other known aetiologies, including Kawasaki disease. Cardiovascular involvement is common; left ventricle dysfunction and coronary artery aneurysm (CAA) are also observed. Many treatment guidelines recommend using intravenous immunoglobulin (IVIG) alone or with glucocorticoids as the first-line therapy. Biological agents, such as anakinra, are recommended for refractory cases, but the evidence is still accumulating. Moreover, the use of other treatment agents can be beneficial, especially when anakinra is unavailable. Here, we report the case of a 9-year-old girl who presented with MIS-C with CAAs. She received cyclosporine because two rounds of IVIG treatment were ineffective and the use of anakinra is not approved in Japan. Her cytokine profile showed that cyclosporine prevented exacerbation. The case highlights that cyclosporine therapy can be an option for the treatment of refractory MIS-C with CAA.