Successful Rituximab Therapy in Steroid-Resistant, Cryptogenic Organizing Pneumonia: A Case Series

Abstract

Cryptogenic organizing pneumonia (COP) is an interstitial lung disease that is usually responsive to corticosteroid treatment. The treatment of COP has not been studied in randomized controlled trials; thus, treatment decisions are based on practice guidelines. We herein present, for the first time, 4 cases of patients with biopsy-proven COP who did not respond to corticosteroids but benefited from rituximab therapy. This report consists of a retrospective case series of patients who experienced steroid-resistant, biopsy-proven COP. Patients included in this case series suffered from acute or chronic COP and did not respond to corticosteroid treatment for a few weeks to months but later responded to rituximab. In a series of 4 patients, 1 patient had a complete radiological and clinical response after rituximab therapy, and the steroids could be gradually tapered. Three patients had a chronic course but had been able to lower steroid dosage or even discontinue the drug after being treated with rituximab. Since 40% of the patients with COP do not respond to or stay dependent on steroids, we think that even the ability to lower the steroid dosage by using rituximab as a steroid-sparing agent with a good safety profile is worth the effort. However, further studies are warranted.