Corticosteroid Therapy in Post-COVID-19 Pulmonary Fibrosis

Introduction:Pulmonary fibrosis (PF) is characterized by excessive deposition of extracellular matrix components and destruction of the pulmonary parenchyma. Studies have shown severe Coronavirus Disease 2019 (COVID-19) can lead to PF with residual lung function abnormalities and fibrotic remodeling. As of today, there is no consensus on treatment for PF caused by COVID-19. We are reporting a case series of three post-COVID-19 PF patients treated with tapering prednisone. Case Series:Patient 1 is 52-year-old male presented to the clinic after a 3-month hospital course of COVID-19 requiring hyperbaric hood. He was discharged with 2L of home oxygen. The patient saturated at 95% at rest but desaturated to 70% on exertion. Chest X-ray (CXR) and CT thorax showed diffuse ground glass opacity with pulmonary fibrosis and scarring. Tapering prednisone from 40mg over 1 month was initiated. Follow-up visit after one month confirmed reduce home oxygen requirement. CXR also revealed mild improvement in interstitial infiltrates. Patient 2 is a 56-year-old male hospitalized 2 months ago for COVID-19 where he required non-rebreather mask for oxygen supply. In the office, he complained of shortness of breath on exertion. CXR showed diffuse bilateral airspace opacities and thickened interstitial lung markings. Pulmonary function test (PFT) revealed moderate restrictive pattern with reduced lung volumes. He was sent home with a course of tapering prednisone over 1 month and weekly office follow up. His symptoms improved. Repeat CXR showed improving bilateral diffuse reticular markings. Repeat PFT improved to mild restrictive lung pattern. Patient 3 is a 70-year-old male hospitalized for 1 moth for COVID-19 requiring face mask with recent discharge on 4L home oxygen. After 2 weeks of hospital discharge, the patient still required 2L of oxygen at home. CXR showed streaky lung opacities predominantly in the left lower lung field. The patient was started on tapering prednisone. At 2-month follow-up, he admitted clinical improvement of symptoms and was able to titrate off home oxygen at rest. Repeat CXR also showed improvement of streaky opacity in the left mid/lower lung. Discussion:No evidence-based treatment is available for post-COVID-19 PF. Corticosteroid is used for treatment of acute exacerbation of other forms of PF by decreasing inflammation in the lungs, and therefore may improve symptoms of post-COVID-19 PF. Our patients received 1-month course of tapering prednisone treatment showed mild clinical improvement with no major adverse effect. Further clinical trials should address the utility and risks of corticosteroid in post-COVID-19 PF.