Changes in neutrophil-lymphocyte and platelet-lymphocyte ratios and clinical outcomes in idiopathic pulmonary fibrosis

Background and aims: The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are markers of subclinical inflammation and higher values are associated with worse outcomes in certain conditions, e.g. autoimmune diseases and cancers. We examined the relationship between changes in NLR and PLR and clinical outcomes in patients with idiopathic pulmonary fibrosis (IPF) in the placebo arm of three Phase III trials of pirfenidone. Methods: Patients with IPF randomised to placebo in the ASCEND (Study 016; NCT01366209) and CAPACITY (Studies 004 and 006; NCT00287716 and NCT00287729) trials were included in this exploratory analysis. For each ratio, patients were ranked by ratio changes over 12 months and divided into quartiles, and summary statistics were obtained for each quartile. The relationship between changes in NLR and PLR from baseline to Month 12 and endpoints at Month 12 was examined. Results: Month 12 endpoints based on quartiles as defined by changes in NLR or PLR followed a similar trend. Month 12 endpoints for changes in NLR are presented in the table. Conclusions: In patients with IPF treated with placebo in the pirfenidone Phase III trials, outcomes at Month 12 were generally poorer in patients with the greatest increase in NLR or PLR over 12 months vs the other quartiles. The clinical relevance of these findings is unclear and may warrant further investigation.