Blood Cell Counts and Inflammatory Indexes in Idiopathic Pulmonary Fibrosis

Introduction Inflammatory cells play a role in several idiopathic pulmonary fibrosis (IPF) pathogenesis steps. We aimed to evaluate the predictive value of peripheral blood cell (PBC) counts and inflammation indexes in the prognosis and mortality of IPF. Materials and methods A total of 155 patients with IPF followed between 1 January 2016 and 1 January 2023 were evaluated retrospectively. The baseline values and annual changes for pulmonary function tests and the PBC counts, ratios, and inflammation indexes (leukocyte, neutrophil, platelet, monocyte, lymphocyte, red cell distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), Systemic Immune Inflammation (SII) index, Systemic Inflammation Response Index (SIRI), the Aggregate Index of Systemic Inflammation (AISI)) were recorded. The relation between PBC, ratios, and inflammatory indexes with functional parameters (forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide (DLCO), 6-minute walking test (6MWT), Gender, Age, and Physiology (GAP) index, GAP stage) and mortality were examined. Results It was found that baseline RDW and neutrophil count were negatively correlated with survival time. The prognosis was worse in patients who had an RDW>13.6% and a neutrophil count>5.26×10⁹/L (p = 0.0005 and p = 0.037, respectively). Significant correlations were observed between baseline peripheral blood cell counts, ratios, and index values (leukocyte, monocyte, neutrophil, platelet, monocyte, lymphocyte, NLR, PLR, MLR, SII, SIRI, AISI) and functional parameters (FVC, DLCO, 6MWT, GAP index, GAP stage). However, there was no significant correlation between the yearly changes. Conclusions Increased neutrophils and RDW may be related to the poor prognosis in IPF. Peripheral blood cell counts and inflammatory indices may provide useful information in identifying patients with worse functional status.