Evaluation of Kallistatin Levels in COPD Exacerbations

<b>Introduction:</b> Kallistatin is an enzyme with antioxidative and anti-inflammatory properties and has been shown to provide protection against pneumosepsis, acute respiratory distress syndrome (ARDS), and lung fibrosis. This study revealed the use of kallistatin in the clinical management of COPD. <b>Materials and Methods:</b> Forty-eight COPD patients were evaluated during both exacerbation and stable periods. A control group of 30 healthy individuals was also included. In addition to kallistatin, serum levels of TAS, TOS, OSI, VEGF, and TNF-<i>α</i> were measured. Data were statistically analyzed for the exacerbation and stable periods of COPD patients, as well as the control group. Correlation analysis of serum parameters was conducted, and regression analysis was performed on those with significant results. <b>Results:</b> Serum kallistatin levels were significantly lower in COPD patients compared to the normal population (<i>p</i> < 0.001). Additionally, kallistatin levels were lower during COPD exacerbations compared to the stable period (<i>p</i> < 0.001). Kallistatin levels measured during exacerbations were positively correlated with OSI and VEGF (<i>r</i> = 0.333, <i>p</i>=0.021; <i>r</i> = 0.301, <i>p</i>=0.037, respectively). The relationship between kallistatin and OSI was strongly supported by regression analysis (<i>p</i>=0.049, CI 16.889). <b>Conclusion:</b> Kallistatin is a promising biomarker for distinguishing COPD patients from the normal population and for identifying disease exacerbations.