Treatment of refractory retrobulbar granuloma with rituximab in a patient with ANCA-negative Wegener’s granulomatosis: a case report

Retrobulbar granuloma is one of the serious complications in Wegener’s granulomatosis and often shows resistance to conventional therapy during long-term treatment. The outcome of this complication includes visual loss, orbital and facial deformity, fistula formation, as well as infection. There has been increasing evidence that shows the efficacy of rituximab, a chimeric anti-B cell mAb, for the treatment of autoimmune diseases including Wegener’s granulomatosis. We present a 22-year-old Japanese woman who was diagnosed with Wegener’s granulomatosis complicated by refractory retrobulbar granuloma. She was admitted to our hospital with pain of the right eye and right proptosis during treatment with monthly IVCY for Wegener’s granulomatosis. We diagnosed refractory retrobulbar granuloma by computed tomography (CT) scan and biopsy. She showed a refractory growth of retrobulbar granuloma in spite of negative ANCA. She was also complicated with pulmonary granulomatous lesions in bilateral apices. After approval by an institutional ethical committee and informed consent of this patient, rituximab 375 mg/m² was intravenously administered weekly four times. Concomitant prednisolone 0.5 mg/kg was also administered for 2 weeks and gradually tapered. Treatment of rituximab resulted in prompt relief of symptoms in this case and the reduction of the granuloma. BVAS score also improved from 6 to 0 at 3 months and was kept in remission for 12 months. Circulating CD19-positive cells were kept less than 0.1% during the follow-up. There were no serious adverse events. This case suggests that rituximab is effective for refractory retrobulbar granuloma complicated in Wegener’s granulomatosis even when ANCA titers are negative.