Abstract
Organizing pneumonia (OP) promptly responds to corticosteroids. However, a minority of patients demonstrate corticosteroid resistance or relapse on corticosteroid tapering. We describe post COVID-19 OP patients with clinically inadequate response to corticosteroids but that improved after the addition of Mycophenolate Mofetil (MMF). Case 1: A gentleman was diagnosed with post COVID-19 OP but had suboptimal clinico-physiologic-radiologic response and steroid toxicity during outpatient reviews. MMF was initiated resulting in marked clinical response and quick weaning from corticosteroids. Case 2: A gentleman with post COVID-19 OP relapsed during tapering of steroids. Clarithromycin and MMF were added to his regimen, which improved his clinico-physiologic parameters and allowed corticosteroid tapering. Unfortunately, he developed MMF-related colitis needing therapy cessation. Currently, no studies have reported on MMF utilization in difficult post COVID-19 OP patients. Nevertheless, we believe, similar as in non-COVID OPs, MMF or other immunomodulators, potentially have a role in treating difficult or steroid-resistant OPs.