Combined Eosinophil, CT Measures Predict Smell Recovery After CRSwNP Surgery

A recent study found that combining the eosinophil-to-lymphocyte ratio (ELR) with computed tomography-based measures—specifically the ethmoid-to-maxillary sinus (E/M) ratio or the ethmoid-minus-maxillary (E–M) score—can predict olfactory recovery in patients with chronic rhinosinusitis with nasal polyps (CRSwNP).1

“Our findings indicate that while [threshold-discrimination-identification score] does not predict outcomes in the sense of forecasting improvement, it does reflect the state of olfactory function,” wrote study investigator Liufeiyan Fan, PhD, from the department of otolaryngology at Xijing Hospital, The Air Force Military Medical University, in China, and colleagues.

Eosinophils in the peripheral blood and nasal tissues are thought to play a key role in the pathogenesis of CRSwNP, with higher mucosal infiltration levels closely linked to more severe disease and greater olfactory dysfunction.2 Although functional endoscopic sinus surgery (FESS) is effective in improving CRSwNP symptoms, its effect on olfactory recovery has been less clearly defined. This study aimed to determine whether integrating eosinophil-derived markers like ELR with E/M or E–M computed tomography scores could improve the prediction of olfactory recovery in these patients.1

Investigators conducted a single-center, retrospective cohort study at the First Affiliated Hospital of the Air Force Medical University from January 2022 to June 2024. The sample (aged 18 – 55 years) included 137 patients with CRSwNP (74% males; median age, 40 years; median disease duration, 4 years) and 52 healthy controls. The Mann-Whitney U test demonstrated that the CRSwNP group had significantly greater levels of Eos, Baso, and ELR than the control arm (all P <.05).

Among participants with CRSwNP, the threshold-discrimination-identification score improved from 10 (IQR, 7 – 24) pre-surgery to 26 (IQR, 15 – 33) at 6 months post-surgery. Participants had a median improvement of 7 (IQR, 2 – 14).

Based on preoperative olfactory function testing, patients were categorized into 3 groups: normosmia (n = 21), hyposmia (n = 27), and anosmia (n = 89). Analyses showed that more patients in the anosomia group had allergic rhinitis, asthma, and atopy compared to the normosmia and hyposmia groups (all P < 0.05). Furthermore, the Kruskal-Wallis H test revealed significant differences in VAS scores for nasal sinus symptoms, total VAS scores, SNOT-22 scores, WBC, Eos, ELR, Lund-Kennedy score, Lund-Mackay score, E score, M score, E/M ratio, and E-M score across the different olfactory function groups (P <.05).1

Post hoc pairwise comparisons using the Friedman test showed that these parameters increased across the groups, with the lowest levels in patients with normosmia, higher levels in those with hyposmia, and the highest levels in those with anosmia. This pattern—particularly the rise in white blood cell (WBC) count—suggests that greater inflammation may underlie more severe olfactory dysfunction.

In contrast, scores reflecting olfactory ability (T, D, I, and total TDI) declined from normosmia to hyposmia to anosmia. The Wilcoxon signed-rank test further showed that patients with anosmia experienced a significantly greater improvement in the threshold-discrimination-identification score compared with those with hyposmia (P < 0.05), indicating that individuals starting with more severe smell loss may have a greater capacity for recovery.

Investigators concluded by stating that the model based on eosinophil-derived indicators combined with computed tomography scores to predict olfactory function recovery is convenient and effective. Although the model shows strong predictive performance, investigators noted that larger, multicenter studies are needed to confirm its use in clinical practice.

“This information is crucial for clinicians to set realistic expectations for patients and to tailor interventions accordingly,” investigators wrote.1 “For instance, patients with a low preoperative TDI score might benefit from more aggressive management strategies, including optimized surgical techniques and postoperative care, to maximize the potential for olfactory recovery.”

References

1. Fan L, Zheng Z, Bai H, et al. Predictive value of ELR combined with CT scores for olfactory recovery in CRSwNP. Ann Allergy Asthma Immunol. Published online October 16, 2025. doi:10.1016/j.anai.2025.10.009

2. Wu D, Li Y, Bleier BS, Wei Y. Superior turbinate eosinophilia predicts olfactory decline in patients with chronic rhinosinusitis. Ann Allergy Asthma Immunol. 2020;125(3):304-310.e1. doi:10.1016/j.anai.2020.04.027