Rituximab in the treatment of refractory pulmonary sarcoidosis

To the Editor: Sarcoidosis is a chronic disease characterised by granulomatous depositions that can occur in virtually any organ system 1. Currently, there is no US Food and Drug Administration (FDA)-approved therapy for sarcoidosis; however, corticosteroids have proven efficacious and are a commonly used treatment 2. In patients with chronic or pulmonary disease who do not respond to corticosteroids, or in whom steroid use is contraindicated, agents such as methotrexate, azathioprine and tumour necrosis factor (TNF)-α antagonists may be effective 3, 4. However, a need persists for patients who fail to respond to current options. Sarcoidosis is a T-cell-mediated disease; however, humoral mechanisms may play a role in its pathogenesis 5. Sarcoidosis is often associated with hypergammaglobulinaemia, autoantibody production and circulating immune complexes 6. B-cell-targeted therapies have shown positive results in many T-cell-mediated autoimmune diseases. Rituximab is a chimeric monoclonal antibody that causes depletion of CD20+ B-cells 7. Rituximab is FDA approved for the treatment of rheumatoid arthritis, granulomatosis with polyangiitis (Wegener’s) and microscopic polyangiitis, and is also being studied in Sjogren’s syndrome, systemic lupus erythematosus and vasculitis 8. There have been case reports of the effectiveness of rituximab for sarcoidosis 9–11. Given the evidence for humoral involvement in sarcoidosis pathogenesis, this study sought to evaluate the utility of B-cell depletion using rituximab in patients with refractory pulmonary sarcoidosis. This was a prospective, open-label, phase I/II trial. The study was approved by the …