Successful treatment of HTLV-1-related overlap syndrome using tacrolimus

A 56-year-old HTLV-I-positive woman, initially diagnosed as having Sjögren's syndrome, presented with muscle weakness, myalgia, face erythema and leg edema. Based on the presence of various autoantibodies, the diagnosis of overlap syndrome (dermatomyositis/Sjögren's syndrome) was made. Treatment with high-dose corticosteroid plus cyclosporine improved her symptoms. However, three months after the start of these treatments, exacerbation of myositis occurred. A muscle biopsy revealed prominent perivascular accumulation of mononuclear cells with perifascicular atrophy, which were consistent with dermatomyositis. Tacrolimus, which was substituted for cyclosporine led to marked improvement of the myositis symptoms.