2.1 Design, setting, and participants
A cross-sectional study of CRS patients undergoing ESS was conducted.
CRS patients were recruited from ”Blinded for review” according to a
protocol approved by the Institutional Review Board of ”Blinded for
review” (ethics approval number 25-36) as described
previously11. Informed consent was obtained from all
participants. All experiments were conducted according to the
Declaration of Helsinki on biomedical research involving human subjects.
Sinonasal tissues, such as uncinate tissues and nasal polyps, were
obtained during ESS, and peripheral blood samples were collected
preoperatively (the day before ESS) and postoperatively. The diagnosis
of CRS was made based on clinical, endoscopic, and radiographic criteria
as described in the European Position Paper on Rhinosinusitis and Nasal
Polyps (EPOS) 20201. A detailed list of the patient
characteristics is presented in Table 1. The CRS cases were classified
as eCRS or non-eCRS according to a published clinical scoring system
(JESREC score)5. The JESREC score was calculated with
the following point breakdown: bilateral disease sites (3 points); nasal
polyps (2 points); CT shadow, ethmoid > maxillary sinus (2
points); and blood eosinophilia, 2% to 5% (4 points), 5% to 10% (8
points), or more than 10% (10 points). Patients with scores higher than
11 points and mucosal eosinophilia higher than 70 per high-power field
were defined as eCRS patients. Conservative medical treatments and nasal
saline irrigations had previously failed in all CRS patients. The
patients were not treated with systemic corticosteroids (SCS) within 4
weeks before the surgery. Patients for whom postoperative blood samples
were unavailable were excluded from the study.