Tocilizumab for refractory cerebral arteritis in a patient with systemic lupus erythematosus

Cerebral arteritis is a rare (<1%) but life-threatening manifestation of systemic lupus erythematosus (SLE). The optimal treatment for cerebral arteritis in refractory cases remains unclear; conventional immunosuppressive therapy results in an improvement in arterial stenosis in only 29% of reported cases. We report the case of a 51-year-old woman with a 20-year history of SLE and rheumatoid arthritis who developed aphasia and right hemiparesis due to a haemodynamic cerebral infarction caused by cerebral arteritis. Despite treatment with high-dose glucocorticoids, intravenous cyclophosphamide, mycophenolate mofetil, and anifrolumab, the disease remained progressive with persistently elevated C-reactive protein levels and worsening arterial stenosis on magnetic resonance angiography. Cerebrospinal fluid interleukin-6 level was markedly elevated (1590 pg/ml). After switching from anifrolumab to tocilizumab, C-reactive protein levels normalised, the patient's neurological condition stabilised, and follow-up magnetic resonance angiography suggested an improvement in arterial stenosis. Tocilizumab might be a viable treatment option for refractory cerebral arteritis in patients with SLE, particularly in cases with elevated cerebrospinal fluid interleukin-6 levels. To our knowledge, this is the first reported case suggesting the potential efficacy of tocilizumab in SLE-related cerebral arteritis.