Methods: Serum sCD93 levels of 116 asthmatic patients were determined and correlated with comorbidity, medical condition, medication history, lung function, and serologic and sputum markers.
Results: The mean serum sCD93 level was 115.4 ± 34.8 ng/mL (range, 36.3–241.0 ng/mL). Serum neutrophil level (standardized coefficient −0.232, P = 0.027) and forced expiratory volume in one second/forced vital capacity (FEV1/FVC; standardized coefficient −0.322, P = 0.015) were negatively correlated with sCD93 levels. sCD93 levels showed no significant correlation with serum eosinophil, sputum eosinophil, sputum neutrophil levels, and FEV1. sCD93 levels were significantly lower in high-dose inhaled corticosteroid (ICS) users (84.1 ± 28.9 ng/mL) than those in ICS non-users (128.9 ± 35.8 ng/mL) and low-medium-dose ICS users (114.5 ± 33.2 ng/mL). The high-sCD93 group had significantly heavier smoking history than the other groups.
Conclusions: The serum sCD93 levels are associated with neutrophilic inflammation and ICS dose in asthmatic patients. We suggest that sCD93 has potential as a novel biomarker that reflects the level of inflammation and as a follow-up marker during ICS use.