Charcot-Leyden Crystals Identified as Potential Biomarker for CRSwNP

Researchers have determined there is potential for Charcot-Leyden crystals (CLC) in nasal tissue to act as a biomarker of recurrence of chronic rhinosinusitis with nasal polyps (CRSwNP).

“Previous study data show potential for nasal polyp recurrence from the presence of protein and mRNA levels of CLCs in nasal secretions,” the authors noted, whether the crystalline CLC structures in nasal tissue could serve as an effective biomarker to predict polyp recurrence remains unclear.”

Their retrospective study findings were recently published in Clinical & Translational Allergy from their investigation of outcomes among 110 patients with CRSwNP who underwent endoscopic sinus surgery at The Third Affiliated Hospital of Sun Yat‐sen University between January and December 2016. They were followed for up to 2 years and hematoxylin and eosin staining were used to identify CLCs. Binary logistic regression was employed to determine predictive factors.

Thirty percent (n = 33) of the patient cohort developed recurrent polyps over the course of the study. Compared with the patients who did not experience nasal polyps recurrence (n = 77), those in the recurrent group had a median age of 39 (range, 32.00-48.50) vs 44 (range, 32.00-51.50) years; 84.85% vs 51.14%, respectively, were male patients; the rate of comorbid asthma was 27.27% compared with 7.79%; and Visual Analogue Scale scores were higher for nasal obstruction (6.00 [range, 4.25-8.00] vs 5.50 [range, 3.00-9.00]), rhinorrhea (5.00 [range, 2.25-7.75] vs 3.00 [range, 1.00-5.25]), and olfactory disorder (6.50 [range, 4.25-9.75]) vs 4.00 [range, 1.75-9.10]).

In addition, levels of CLCs and eosinophils (both P < .001) in peripheral blood, both as a percentage (P = .001) and for count (P < .001), were significantly higher in the recurrent group compared with the recurrent-free group.

Overall, 26.36% of patients with CRSwNP and 64.44% who had eosinophilic CRSwNP had bipyramidal CLC structures. No CLCs were seen among either group for the patients who had noneosinophilic CRSwNP. In addition, the recurrent group had far more patients with eosinophilic CRSwNP (87.88%) compared with noneosinophilic CRSwNP (12.12%).

“These results suggest CLCs, similar to eosinophils, are closely associated with NPs recurrence,” the researchers posited.

To get more specific regarding postop factors associated with polyps recurrence, the study authors employed a logistic regression analysis. Higher chances of recurrence correlated with the following factors:

• Tissue CLC count (odds ratio [OR], 2.203; 95% CI, 1.256-3.865; P = .006)
• Higher tissue eosinophil count (OR, 1.077; 95% CI, 1.045-1.109; P < .001)
• Male gender (OR, 3.895; 95% CI, 1.330-11.403; P = .013)
• Presence of comorbid asthma (OR, 3.974; 95% CI, 1.229-12.850; P = .021)
• Peripheral blood eosinophil count (OR, 3.804; 95% CI, 1.003-14.428; P = .049)
• Peripheral blood eosinophil percentage (OR, 1.096; 95% CI, 1.011-1.187; P = .025)

Yet another analysis indicated CLCs to be independent factors for nasal polyps recurrence. Higher odds of 1.078 (OR, 2.078; 95% CI, 1.269-3.402; P = .004) were seen following multiple logistic regression analysis that excluded the influence of male gender age, comorbid allergic rhinitis, comorbid asthma, and atopic status.

In addition, total CLCs (area under the curves [AUC], 0.919; 95% CI, 0.845-0.993; P < .001) and number of eosinophils (AUC, 0.897; 95% CI, 0.804-0.990; P < .001) in NPs were shown to provide high predictive value for polyp recurrence.

A main limitation on generalizability of these findings the authors highlighted is that intra-individual comparisons of CLCs in NP tissue, nasal mucosa tissue, and nasal secretion were not carried out, so the optimal form of CLC as a predictor is left up for debate. Future studies should “compare the sensitivity and specificity of distinct forms of CLC with different biopsies for predicting nasal polyps relapse,” they emphasized.

Reference

Chen W, Bai Y, Kong W, et al. Predictive significance of Charcot-Leyden crystal structures for nasal polyp recurrence. Clin Transl Allergy. 2022;12(11):e12212. doi:10.1002/clt2.12212