Blau syndrome with good Reponses to Tocilizumab: A case report and focused literature review

Blau syndrome (BS), a rare auto-inflammatory granulomatous disease, is a progressive disorder. Usually the maintenance dose of glucocorticoid may not be tapered below 15 mg per day while immunosuppressives is used. There has been some experience with biologic agents in refractory BS patients. The objective of this study is to describe the case of a BS patient benefiting from Tocilizumab, a humanized monoclonal antibody against interleukin 6 receptor. We report the first Chinese patient with BS who was resistant to currently available therapies but had rapid quiescence after using Tocilizumab. We also conducted a systematic literature review about the current treatments of BS. A 13-year-old Chinese boy with BS, whose uveitis got worsened when treated with Infliximab, was well-controlled after taking Tocilizumab and prednisone was tapered off to a dose of 8 mg per day. We identified 29 manuscripts providing 45 BS cases. Among these patients, 24 underwent biological treatments and 22 of them recovered. In these 29 manuscripts, the biological agents used to treat refractory BS included Etanercept, Infliximab, Adalimumab, Canakinumab and Anakinra. Case reports on the use of biological agents have yielded mixed results. The diversity of the symptoms may be due to functional differences in NOD2 mutations. For BS patients with fever, lymphadenopathy and hepatosplenomegaly, Tocilizumab may be a better choice.