THE ROLE OF CHITOTRIOSIDASE ACTIVITY AS A PROGNOSTIC BIOMARKER IN SARCOIDOSIS

Abstract

Introduction: Chitotriosidase (ChT) is a chitinase that is massively expressed by lipid-laden tissue macrophages in human beings. The aim of this study was to compare ChT activities in the serum and bronchoalveolar lavage (BAL) fluid and serum ChT levels with serum angiotensin converting enzyme (ACE) levels in patients with newly diagnosed pulmonary sarcoidosis (SARC), pulmonary tuberculosis (TB) and interstitial lung disease (ILD), all of which create difficulties in the differential diagnosis in daily practice. Materials and methods: ACE concentration and ChT activity were measured in pulmonary TB (n=28), SARC (n=37), and different types of ILD (n=23). ChT activities in the serum, BAL fluid and serum ACE concentrations were determined using ELISA kits. Results: Serum ACE levels were significantly higher in the SARC patients than those in the TB and ILD patients (p<0.001). There were no differences among patients regarding ChT activities in serum and BAL fluid. ChT activities in the BAL fluid and serum did not correlate with serum ACE levels. Conclusion: Our results indicate that, ChT cannot be considered as a specific marker of SARC since ChT activities were also increased in TB and ILD. ACE level seemed to be a more specific biomarker for SARC than ChT. Further studies are required to better understand the role of ChT and ACE concentrations in the pathogenesis of SARC and their involvement in fibrotic remodeling in certain types of diffuse lung diseases.