Soluble CD93 in Serum as a Marker of Allergic Inflammation

Purpose: CD93 is receiving renewed attention as a biomarker of inflammation. We aimed to evaluate the potential for serum sCD93 to serve as a novel biomarker for allergic inflammation. Materials and Methods: We enrolled 348 subjects with an allergic disease [allergic rhinitis (AR), chronic spontaneous urticaria (CSU), or bronchial asthma (BA)], including 14 steroid-naive BA patients who were serially followed-up. Results: The serum sCD93 levels (ng/mL) in patients with exacerbated AR (mean +/- standard deviation, 153.1 +/- 58.4) were significantly higher than in patients without AR (132.2 +/- 49.0) or with stable AR (122.3 +/- 42.1). Serum sCD93 levels in exacerbated CSU (169.5 +/- 42.8) were also significantly higher than those in non-CSU (132.4 +/- 51.6) and stable CSU (122.8 +/- 36.2). This trend was also seen in BA. Serum levels in patients with ICS-naive BA (161.4 +/- 53.1) were significantly higher than those in healthy controls without BA (112.2 +/- 30.8), low-and medium-dose ICS users. Serum sCD93 levels in high-dose ICS users (72.2 +/- 20.6) were significantly lower than those in low-and medium-dose users. The serum sCD93 levels in steroid-naive patients with BA (195.1 +/- 72.7) decreased after ICS use for 4 weeks (134.4 +/- 42.8) and 8 weeks (100.7 +/- 13.4), serially. Conclusion: Elevated serum sCD93 levels reflected exacerbated status of allergic diseases, including CSU, AR, and asthma. ICS use significantly diminished serum sCD93 levels in steroid-naive patients with BA. This result may suggest sCD93 in serum as a therapeutic marker for allergic inflammation.