Late-onset neutropenia during long-term rituximab therapy in neuromyelitis optica

Late-onset neutropenia (LON) has been described as a side effect of rituximab (RX) therapy in patients with rheumatological and/or haematooncological diseases but not neuromyelitis optica (NMO). We describe a 71-year old female patient, who had NMO for 22 years, had been treated with RX monotherapy five times (cumulative dosage: 11g; duration of treatment: 3 years) before she developed severe neutropenia (IV) 3 months after the last RX infusion.(1) After exclusion of other causes, the diagnosis of LON was made. No complications occurred and neutropenia resolved without therapy. RX therapy was continued with intensive monitoring without any further LON and/or complications. In conclusion LON is a possible side effect during RX therapy and may also occur in NMO patients.