Corticosteroid treatment for post-COVID-19 persistent interstitial lung disease: a randomized clinical trial

This study aimed to evaluate the efficacy of prednisolone in the treatment of persistent interstitial lung disease following severe SARS-CoV-2 pneumonia. A single-center, randomized, double-blind, placebo-controlled clinical trial was conducted. All participants presented residual pulmonary opacities on high-resolution chest computed tomography 4-months after COVID-19 diagnosis. Patients received either prednisolone (1 mg/kg/day for 1-month followed by gradual dose reduction) or placebo and were reassessed after 3- and 6-months of follow-up. Evaluations included clinical assessment; measurement of erythrocyte sedimentation rate, C-reactive protein, and D-dimer levels; pulmonary function tests; 6-Minute Walk Test (6MWT); Modified Medical Research Council (MRC) dyspnea scale; Short Form-36 (SF-36) quality of life questionnaire; and Post-COVID-19 Functional Status (PCFS) Scale. Statistical analyses were performed using analysis of variance (ANOVA) and log-binomial regression models. The placebo group (n = 31) comprised 60% male participants with a median age of 51-years, whereas the prednisolone group (n = 35) included 52% male participants with a median age of 53-years. Baseline comorbidities and treatments prior to randomization were comparable between groups. During follow-up, forced vital capacity (% predicted) increased from 78% to 89% in the placebo group and from 83% to 91% in the prednisolone group. Significant improvements were also observed in forced expiratory volume in one second, diffusion lung capacity, and maximal expiratory pressure in both groups. No significant differences were identified between groups regarding MRC dyspnea scores, SF-36 domains, or PCFS scale at baseline or at the final evaluation. Functional capacity scores in the SF-36 increased from 55 to 71 in the placebo group and from 57 to 69 in the prednisolone group. Walking distance increased significantly only in the prednisolone group. Tomographic variables demonstrated similar progression patterns in both groups throughout follow-up. In conclusion, systemic corticosteroid therapy with prednisolone did not provide additional benefits in patients with post-COVID interstitial lung disease. Both placebo and prednisolone groups exhibited comparable functional improvements over the six-month follow-up period.