An immunologic test for chronic rhinosinusitis based on free intranasal eosinophilic major basic protein

Area of Science:

• Otorhinolaryngology
• Immunology
• Biomarker Discovery

Background:

• Chronic rhinosinusitis (CRS) is characterized by eosinophilic inflammation, with eosinophils releasing major basic protein (MBP) into nasal mucus.
• Current diagnostic methods for CRS lack specific biomarkers with high sensitivity and specificity.
• An enzyme-linked immunosorbent assay (ELISA) for detecting MBP in nasal mucus has recently gained regulatory approval.

Purpose of the Study:

• To evaluate the diagnostic utility of free major basic protein (MBP) in nasal mucus for chronic rhinosinusitis (CRS).
• To assess the sensitivity and specificity of an MBP ELISA test in distinguishing CRS from healthy controls and allergic rhinitis.

Main Methods:

• Developed a novel assay to detect released MBP in airway mucus.
• Compared MBP levels in nasal mucus from 85 CRS patients against 13 healthy and 5 allergic rhinitis controls.
• Utilized endoscopy, CT scans, and symptom assessment for CRS diagnosis in patients.

Main Results:

• The MBP ELISA detected MBP in 92% of CRS patients (mean 7722 ng/mL).
• No MBP was detected in healthy controls or allergic rhinitis patients (<7.8 ng/mL).
• The MBP ELISA demonstrated 92% sensitivity and 100% specificity for diagnosing CRS.

Conclusions:

• Free MBP in nasal mucus serves as a reliable biomarker for CRS diagnosis.
• The MBP ELISA is the first immunological test capable of distinguishing CRS from eosinophilic inflammation in allergic rhinitis.
• This assay holds potential for improved diagnostic accuracy in CRS.