Respiratory syncytial virus pneumonitis complicating immunosuppressive treatment for ANCA-positive vasculitis.

We present a case of acute respiratory failure developing in a patient given immunosuppression for anti-neutrophil cytoplasm antibody (ANCA)-positive renal vasculitis. With these interventions, however, comes the increased risk of infective complications. This case highlights a highly unusual (but probably underdiagnosed) infection, respiratory syncytial virus (RSV), associated with severe pneumonitis. This pathogen is associated with bronchiolitis in infants and outbreaks of pneumonia in the elderly. Previous reports associating RSV with immunosuppression have virtually exclusively focused on lung and bonemarrow transplant recipients.