A Case of Autoimmune Neutropenia That Responded to Rituximab.

Autoimmune neutropenia (AIN) refers to the immune-mediated destruction of neutrophils. It is a rare condition with an estimated prevalence of less than 1 case per 100,000 per year. Typical treatment involves supportive care with granulocyte colony-stimulating factor (G-CSF) and management of secondary infections with antibiotics. Other therapies targeted at the immune system such as steroids, intravenous immunoglobulin (IVIG), and rituximab have not been thoroughly evaluated, but recently rituximab has shown promising results in one case series. We present a 76-year-old man with the diagnosis of antineutrophil antibody-negative AIN and concurrent immune thrombocytopenic purpura (ITP), whose AIN was treated initially with G-CSF which had a short-lived effect, then treated with rituximab which induced a lasting remission. We then review this case in context of other cases described in the literature, given the paucity of available publications.