BACKGROUND: Recent publications have suggested that neutrophil elastase (NE) may have a role in evaluating the clinical condition of patients with interstitial lung diseases (ILD). This study aims to evaluate the role of serum NE levels in the follow-up of patients with ILD. MATERIAL/METHODS: A group of 100 consecutive patients diagnosed with various ILDs were prospectively studied on two successive visits. On the first visit, the clinical condition of each patient was assessed, and blood count, pulmonary function tests, chest x-ray and serum NE levels (by latex agglutination assay) were performed on all patients. On the second visit, 8 months later, the patients were classified in two groups: those with unfavorable progression and those who were either in the same clinical status or showed good progression. RESULTS: There was a weak correlation between NE and age (r= -0.383; p < 0.0005). Sex, age, NE and the treatment received were found to be independent predictors of the initial clinical condition. Multivariate analysis including these variables demonstrated that higher levels of serum NE predicted the worst clinical presentation (odds ratio: 4.392; 95% CI: 1.665 - 11.586; p = 0.003). However, none of the variables were found to be significantly different when the progression of the disease was assessed. CONCLUSIONS: Although NE seems to be a good marker for the initial clinical condition in this group of diseases, its role as a prognostic factor could not be proven

Keywords: Leukocyte Elastase - blood, Lung Diseases, Interstitial - blood, Lung Diseases, Interstitial - pathology, Lung Diseases, Interstitial - therapy