Evaluating the efficacy of prednisolone for silicosis with progressive massive fibrosis in Australia: an observational pilot study.

BACKGROUND: There has been a resurgence of silicosis, particularly related to artificial stone. There are currently no treatments for silicosis beyond lung transplantation for end-stage disease. This study aimed to evaluate the efficacy of prednisolone in people with artificial stone-associated silicosis-progressive massive fibrosis (PMF). METHODS: This was a pilot prospective observational clinical trial, assessing 3 months of prednisolone in adults with artificial stone-associated silicosis with PMF. Outcomes were assessed at 3 and 12 months. RESULTS: Seven participants completed the study. Baseline positron emission tomography (PET) scans demonstrated increased fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in areas of PMF in all participants. All participants had a significant reduction in maximum standardized uptake value (SUVmax) following prednisolone at 3 months (pre-treatment mean SUVmax 6.7 [standard deviation (SD): 2.6], post-treatment mean SUVmax 4.2 [SD: 1.0], p = 0.012). There was also a non-significant reduction in the % of total lung parenchyma with SUV >1 (49.7% [SD: 36.4] to 45.8% [SD: 28.4], p = 0.527) and a significant reduction in SUV >2.5 (7.0% [SD: 6.3] to 2.4% [SD: 2.2], p = 0.038). There was a non-significant reduction in computed tomography ICOERD well-defined opacity profusion scores and large opacities. There was no significant difference in lung function or St. George's Respiratory Questionnaire. There were no serious adverse events. CONCLUSIONS: There are high levels of inflammation in silicosis-PMF as evidenced by 18F-FDG PET. Short-term prednisolone reduced 18F-FDG PET activity. This suggests a possible therapeutic pathway for people with silicosis-associated PMF in a population with no current treatments. Further research is required to determine the most appropriate immunosuppressive strategy and further assess longer-term outcomes.