Using magnetic resonance imaging to quantify the inflammatory response following allergen challenge in allergic rhinitis

• Published in: Immunity, Inflammation and Disease Vol. 3; no. 4; pp. 445 - 454
• Main Authors: Leaker, Brian R., Scadding, Glenis, Jones, C. Richard, Barnes, Peter J.
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.12.2015; John Wiley and Sons Inc
• Subjects: Acoustic rhinometry; Acoustics; allergic rhinitis; Allergies; Drug dosages; Inflammation; MRI; nasal allergen challenge; Nitric oxide; NMR; Nose; Nuclear magnetic resonance; Original Research; Pharmaceuticals; Research funding; Studies; United Kingdom > UK; nasal allergen challenge; allergic rhinitis; Acoustic rhinometry; MRI
• ISSN: 2050-4527; 2050-4527
• DOI: 10.1002/iid3.86

Current rhinometric and flow assessments measure nasal patency and are often poorly correlated with rhinitis symptoms. To evaluate magnetic resonance imaging (MRI) as a new method to measure inflammatory changes in nasal and sinus mucosa following nasal allergen challenge. A pilot study (n = 6) determined the optimal technical settings for MRI to measure inflammatory change which were then adopted for the main study. This study was a single blind, placebo‐controlled, three‐way crossover trial in 14 subjects with seasonal allergic rhinitis. Effects of cetirizine, cetirizine and pseudoephedrine (Cet+PE), or placebo on total nasal symptom scores (TNSS), peak nasal inspiratory flow (PNIF), nasal nitric oxide (nNO), acoustic rhinometry, and MRI end points following nasal intranasal allergen challenge were measured. There were significant changes in all parameters after allergen challenge (P < 0.01), except for nNO. MRI end points were less variable and more consistent than PNIF and acoustic rhinometry in detecting changes after allergen challenge. Total nasal airspace volume was the most sensitive and reproducible MRI measurement, with a mean reduction from −5.37 cm3 (95%CI −7.35, −3.38; P < 0.001), which was maximal 60 min after allergen challenge. A change of one in TNSS corresponded to a change in MRI volume of −0.57 cm3. There was an improvement in all parameters (except nNO) in subjects taking Cet+PE compared with placebo, however this did not achieve significance probably because of the small study size (overall analysis P > 0.07; comparison of active versus placebo P > 0.09). MRI provides novel insights into the anatomical inflammatory changes post allergen challenge and provides a new method for assessment of nasal patency and objective measurement of inflammatory responses. This is the first reported study of the use of MRI where this technique has been used to quantify the inflammatory changes following nasal allergen challenge. MRI provides an objective method for the assessment of the response to nasal challenge, which merits further study. MRI provides novel insights into the anatomical changes in response to allergen and provides a new method for the assessment of nasal patency, vascular congestion, and inflammation.