Affiliation:
1. Mayo Clinic Alix School of Medicine Mayo Clinic Arizona Scottsdale Arizona USA
2. Division of Allergy, Asthma, and Clinical Immunology Mayo Clinic Arizona Scottsdale Arizona USA
3. Department of Otorhinolaryngology‐Head and Neck Surgery Mayo Clinic Arizona Phoenix Arizona USA
Abstract
ObjectiveTo evaluate eosinophil peroxidase (EPX) as a biomarker for tissue levels of eosinophilia, cytokines, and chemokines within chronic rhinosinusitis (CRS).MethodsTwenty‐eight subjects undergoing sinonasal surgery were prospectively enrolled. Ethmoid tissue was analyzed with an in‐house EPX immunoassay and a 48‐plex cytokine‐chemokine array. Clinical severity was assessed using SNOT‐22 and Lund‐Mackay scores. Subjects were grouped as follows: controls, polyp status (CRS with [CRSwNP] and without nasal polyps [CRSsNP]), tissue eosinophilia (eosinophilic CRS [eCRS], non‐eosinophilic CRS [neCRS]), or combinations thereof (eCRSwNP, eCRSsNP, neCRSsNP). eCRS was defined as >10 eosinophils per high power field (HPF). Subjects without CRS or asthma were enrolled as controls.ResultsEPX was elevated in CRSwNP compared to control (p = 0.007), in eCRS compared to neCRS (p = 0.002), and in eCRSwNP along with eCRSsNP compared to neCRSsNP (p = 0.023, p = 0.015, respectively). eCRS displayed elevated IL‐5 compared to neCRS (p = 0.005). No significant differences in EPX or IL‐5 were observed between eCRSwNP and eCRSsNP. IL‐5 was elevated in eCRSwNP (p = 0.019) compared neCRSsNP. Area under the receiver operator characteristic curve was 0.938 (95% CI, 0.835–1.00) for EPX and tissue eosinophilia, with an optimal cut‐point of 470 ng/mL being 100% specific and 81.25% sensitive for tissue eosinophilia. Linear regression revealed a strong correlation between EPX and IL‐5 (R2 = 0.64, p < 0.001). Comparing EPX and IL‐5, only EPX displayed significant correlation with SNOT‐22 (p = 0.04) and Lund‐Mackay score (p = 0.004).ConclusionEPX is associated with tissue eosinophilia in CRS patients regardless of polyp status. EPX correlates with IL‐5 and could be potentially considered a biomarker for anti‐IL‐5 therapies.Level of Evidence3 Laryngoscope, 134:69–78, 2024
Funder
Division of Intramural Research, National Institute of Allergy and Infectious Diseases
Flinn Foundation