Hepatic veno-occlusive disease accompanied by thrombotic microangiopathy developing during treatment of juvenile dermatomyositis and macrophage activation syndrome: A case report.

Hepatic veno-occlusive disease (VOD) is a complication of hematopoietic stem cell transplantation (HSCT). VOD is associated with the occurrence of thrombotic microangiopathy (TMA). In HSCT, VOD and TMA are endothelial syndromes resulting from endothelial cell activation and dysfunction. In rheumatic disease, while TMA is not rare, there are few reports of VOD. In idiopathic myositis, only one case with VOD and TMA complications has been reported, there are no published cases in juvenile dermatomyositis (JDM). We report a case of JDM manifesting VOD and TMA complications during treatment for myositis and macrophage activation syndrome (MAS). A 5-year-old boy diagnosed as anti-nuclear matrix protein 2 antibody-positive JDM was complicated by MAS. He received pulsed methylprednisolone, prednisolone, and tacrolimus, but JDM and MAS progressed. He was then treated with intravenous cyclophosphamide (CY) and cyclosporine A (CsA), with improvement in myositis symptoms and MAS. After initiation of CY and CsA, he developed hemolysis, painful hepatomegaly, liver damage, and ascites. He was diagnosed with VOD and TMA. CY and CsA were discontinued, with recovery from VOD and TMA. The patient remained well on treatment with methotrexate, without any relapse of JDM and MAS to date. The presence of vasculopathy and hypercytokinemia because of JDM and MAS exacerbated endothelial cell damage. In the present case, we suggest that the main cause of VOD was medication with CY and CsA, which had been used to treat acute exacerbation of MAS and JDM.