How to Identify Type 2 Chronic Rhinosinusitis in East Asian Patients

Area of Science:

• Otolaryngology
• Immunology
• Genetics

Background:

• Chronic rhinosinusitis (CRS) is a heterogeneous disease with distinct inflammatory endotypes.
• Eosinophilic CRS (ECRS) is associated with severe symptoms, recurrence, and asthma.
• Accurate identification of Type 2 CRS is crucial for targeted biologic therapies.

Purpose of the Study:

• To critically examine the applicability of current European diagnostic criteria for Type 2 CRS in Asian populations.
• To discuss alternative diagnostic approaches and thresholds for ECRS in Asia.
• To highlight the need for regionally validated criteria for accurate diagnosis and treatment selection in Asian patients.

Main Methods:

• Review of existing literature and diagnostic criteria, including EPOS 2020.
• Analysis of evidence from Korean and Japanese cohorts regarding CRS endotypes and biomarker distributions.
• Evaluation of histological thresholds, scoring systems (JESREC, Korean criteria), and machine-learning approaches.

Main Results:

• Western diagnostic criteria (EPOS 2020) show poor specificity for Type 2 CRS in Asian patients with nasal polyps.
• Asian studies suggest higher histological eosinophil cut-offs (approx. 70 cells/HPF or 10%) for ECRS diagnosis.
• Outpatient-friendly scoring systems and machine-learning approaches show promise for noninvasive ECRS prediction.

Conclusions:

• Current Western criteria for Type 2 CRS are not suitable for Asian populations due to differing inflammatory endotype prevalence.
• Regionally validated criteria integrating histological, serological, and clinical data are essential for accurate ECRS identification in Asia.
• Adoption of tailored diagnostic approaches will optimize biologic therapy selection and improve patient prognosis in Asian CRS patients.