Successful treatment of TAFRO syndrome, a variant type of multicentric Castleman disease with thrombotic microangiopathy, with anti-IL-6 receptor antibody and steroids

TAFRO syndrome is a rare variant type of multicentric Castleman disease, which is characterized by thrombocytopenia, anasarca, reticulin fibrosis of bone marrow, renal dysfunction and organomegaly. Here, we report a case of TAFRO syndrome that was successfully treated with tocilizumab. A 50-year-old man, who presented with fever, epigastric pain, abdominal fullness, and massive edema of the extremities, was admitted to our hospital. Computed tomography revealed bilateral pleural effusions, ascites, and lymphadenopathy. Laboratory data showed renal dysfunction, anemia, and thrombocytopenia. Examination of bone marrow and cervical lymph nodes led to a diagnosis of hyaline vascular-type Castleman disease. The level of serum interleukin (IL)-6 was extremely high. TAFRO syndrome was finally diagnosed. The patient was treated weekly with tocilizumab, an anti-IL-6 receptor antibody and steroids. In 4 weeks, all symptoms disappeared and serum IL-6 level returned to normal. Activity of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13), which was significantly decreased (9.9 %) prior to treatment, increased after treatment with tocilizumab. The present case suggests that tocilizumab is an effective therapeutic agent for TAFRO syndrome. We suggest that hypercytokinemia in TAFRO syndrome inhibits ADAMTS13 activity, thereby inducing thrombotic microangiopathy.