Neutrophil levels correlate with quantitative extent and progression of fibrosis in IPF: results of a single-centre cohort study

Journal article

Background Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with poor prognosis. Clinical studies have demonstrated association between different blood leucocytes and mortality and forced vital capacity (FVC) decline. Here, we question which blood leucocyte levels are specifically associated with progression of fibrosis, measured by accumulation of fibrosis on CT scan using a standardised automated method.Methods Using the Computer-Aided Lung Informatics for Pathology Evaluation and Rating CT algorithm, we determined the correlation between different blood leucocytes (<4 months from CT) and total lung fibrosis (TLF) scores, pulmonary vessel volume (PVV), FVC% and transfer factor of lung for carbon monoxide% at baseline (n=171) and with progression of fibrosis (n=71), the latter using multivariate Cox regression.Results Neutrophils (but not monocyte or lymphocytes) correlated with extent of lung fibrosis (TLF/litre) (r=0.208, p=0.007), PVV (r=0.259, p=0.001), FVC% (r=−0.127, p=0.029) at baseline. For the 71 cases with repeat CT; median interval between CTs was 25.9 (16.8–39.9) months. Neutrophil but not monocyte levels are associated with increase in TLF/litre (HR 2.66, 95% CI 1.35 to 5.25, p=0.005).Conclusion Our study shows that neutrophil rather than monocyte levels correlated with quantifiable increase in fibrosis on imaging of the lungs in IPF, suggesting its relative greater contribution to progression of fibrosis in IPF

Authors: Achaiah, A; Fraser, E; Saunders, P; Hoyles, RK; Benamore, R

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: BMJ Publishing Group
• Journal: BMJ Open Respiratory Research
• Volume: 10
• Issue: 1
• Pages: e001801-e001801
• Publication date: 2023-10-10
• Acceptance date: 2023-09-15
• DOI: 10.1136/bmjresp-2023-001801
• EISSN: 2052-4439
• ISSN: 2052-4439
• Language: English
• Keywords: Pathology; Internal medicine; Receiver operating characteristic; Gastroenterology; Diffusing capacity; Idiopathic pulmonary fibrosis; Fibrosis; Lung; Medicine; Vital capacity