Predictive role of inflammatory markers in characterizing the progression of interstitial lung disease: a retrospective analysis.

Objectives: To evaluate the association between inflammatory markers and interstitial lung disease (ILD) progression in order to enhance disease monitoring and risk stratification.

Methods: This retrospective cohort study analyzed the clinical data from 172 ILD patients admitted to Nanjing Jiangbei Hospital between January 2021 and December 2023. Patients were categorized into two groups: progressive ILD (PILD; n=95) and rapidly progressive ILD (RPILD; n=77), based on changes in symptoms and pulmonary function within six months. PILD was defined by a ≥10% relative decline in predicted Forced Vital Capacity (ppFVC) or related clinical criteria. RPILD was defined by acute symptom worsening and significant pulmonary function deterioration. Inflammatory markers assessed included C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation index (SII).

Results: CRP, NLR, PLR, and SII levels were significantly higher in the RPILD group, while LMR was significantly lower (all P<0.05). Multivariate logistic regression identified CRP, NLR, LMR, and SII as independent predictors of ILD progression. ROC analysis showed NLR had the highest individual predictive value (AUC=0.757). A composite model combining all five markers achieved an AUC of 0.842, indicating improved predictive accuracy.

Conclusions: Inflammatory markers, particularly NLR, are independently associated with ILD progression. A composite model incorporating multiple markers offers enhanced predictive performance, potentially supporting clinical decision-making and early intervention strategies.