[Comparative study on different methods of detecting eosinophils in nasal polyps].

Area of Science:

• Pathology
• Histology
• Medical Diagnostics

Background:

• Accurate eosinophil counting is crucial for diagnosing conditions like Eosinophilic Chronic Rhinosinusitis with Nasal Polyps (ECRSwNP).
• Conventional Hematoxylin and Eosin (HE) staining may present limitations in eosinophil specificity and quantification.
• Standardization of eosinophil counting methods is needed for consistent ECRSwNP diagnosis.

Purpose of the Study:

• To compare the efficacy of Congo red, Chromotrope 2R, and conventional HE staining for eosinophil enumeration in nasal polyps.
• To evaluate the specificity, contrast, and background staining characteristics of each stain.
• To determine which staining methods are most suitable for accurate eosinophil quantification.

Main Methods:

• Nasal polyp tissue samples (n=23) were processed and stained using Congo red, Chromotrope 2R, and HE staining.
• Digital pathology techniques were employed using a digital slice scanner for image acquisition.
• Quantitative analysis of eosinophils was performed using Image J Analysis System, with statistical analysis by GraphPad Prism 5.

Main Results:

• Congo red and Chromotrope 2R staining demonstrated higher specificity for eosinophils than HE staining.
• Chromotrope 2R exhibited the lowest background staining.
• Both Congo red and Chromotrope 2R showed statistically significant differences (P<0.05) in eosinophil counts compared to HE staining, with no significant difference between Congo red and Chromotrope 2R (P>0.05).

Conclusions:

• Congo red and Chromotrope 2R staining are more suitable for precise eosinophil counting in nasal polyps.
• Adoption of these stains can contribute to harmonizing eosinophil count criteria within the ECRSwNP definition.
• Improved staining methods can lead to more reliable diagnoses and treatment strategies for ECRSwNP.