Insights into the diagnostic and prognostic value of paraoxonase 1-related variables and inflammatory markers in community-acquired pneumonia.

Community-acquired pneumonia (CAP) remains a major health concern, with oxidative stress and inflammation playing key roles in its pathophysiology. This study examines the potential of paraoxonase-1 (PON1)-related variables as biomarkers for diagnosing and managing CAP. A prospective case-control study included 78 patients with community-acquired pneumonia (CAP) who were hospitalized and 80 healthy controls. Serum PON1 concentration (PON1c), PON1 arylesterase (ARE) and paraoxonase (PARX) activities, and inflammatory markers (C-reactive protein, procalcitonin, and C-C motif chemokine ligand) were measured and compared with lipid profiles and clinical severity scores. Receiver operating characteristic curve analysis was used to assess their diagnostic and prognostic value. CAP patients exhibited significantly lower ARE and PARX activities but higher PON1c levels than controls, with these changes correlating with increased inflammatory markers and decreased total and high-density lipoprotein cholesterol concentrations. PON1-related variables demonstrated strong diagnostic accuracies (areas under the curve > 0.90), outperforming traditional inflammatory markers. However, although these variables provided insights into disease severity and pathophysiology, their prognostic value and ability to differentiate microbial etiologies were limited. These findings suggest that PON1-related variables may serve as promising diagnostic biomarkers for CAP, but their role in prognosis and guiding antimicrobial therapy requires further investigation. Future studies should validate these results in larger and more diverse populations while exploring the mechanistic involvement of PON1 in CAP progression.