A case report: Guillain-Barré syndrome probably associated with TNF inhibitor in Blau syndrome.

backgroundBlau syndrome (BS) is an early-onset autoinflammatory disease, typically characterized by a clinical triad of granulomatous polyarthritis, uveitis and skin lesion. Tumor necrosis factor (TNF) antagonists (TNF inhibitor, TNFi) are used routinely according to treatment guidelines for several refractory BS therapy. However, peripheral nervous system demyelination related to TNFi is being increasingly recognized. Here, we report a case of Guillain-Barré syndrome probably secondary to an TNFi, Yisaipu, one kind of etanercept biosimilars, which is a rare and usually unpredictable adverse drug reaction of TNFi in BS patients. CASE PRESENTATION: A 10-year-old girl was diagnosed with BS due to present with skin rash, multiple joint activity limits, NOD2 gene mutation, granulomatous disorders identified from the pathology of skin and synovium biopsy 6 years ago, and treated by corticosteroids and methotrexate (MTX). Then, she discontinued all treatments and follow-up by herself in 2021. Due to a recurrence of BS, Yisaipu and MTX were given again. After 9 months treatment, the patient developed limb pain, a mouth askew with slurred speech, positive nuchal vigidity, muscle weakness, absent knee jerk and ankle reflexes. Laboratory investigations showed a raised protein level and normal cellular count of CSF, positive anti-sulfatides antibody IgM in CSF and peripheral nerve damage of electromyography. Imaging investigations illustrated enhancement signal of ventral roots, dorsal roots and cauda equina of lumbar MRI.

conclusionsTNFi therapy is increasing every year, so more attention should be paid to the safety of TNF inhibitor therapy, especially nervous system demyelination. The assessment about nervous system should be recommended in regular follow-up among patients receiving TNFi therapy.