Single dose of rituximab causing organising pneumonia in a patient with B-cell lymphoproliferative disorder

Rituximab (RTX) is a monoclonal anti-CD20 antibody used to treat non-Hodgkin's lymphoma. RTX-organising pneumonia (RTX-OP) is a rare complication following treatment with RTX. We report a 49-year-old woman, with CD5-negative B-cell lymphoproliferative disorder who developed high-grade fever, dyspnoea and dry cough 3 days after the first dose of RTX. She responded poorly to antibiotics and antifungal therapy. High-resolution CT (HRCT) of the chest revealed bilateral patchy ground-glass opacities with arcade-like signs suggestive of OP. She was pulsed with intravenous methylprednisolone and RTX was discontinued. She was able to be weaned off the non-invasive ventilation (NIV) support and was discharged with maintenance prednisolone 1 mg/kg and tapered over 6 weeks. A repeated HRCT of the chest at 6 weeks showed a total resolution of OP. This highlights the early occurrence at day 3 of RTX-OP following the first dose of RTX and the complete resolution with steroid therapy.