A disease activity score for ENT involvement in granulomatosis with polyangiitis (Wegener's)

Abstract

Accurate assessment of disease activity in patients with otorhinolaryngological manifestations of granulomatosis with polyangiitis (Wegener's) (ENT/GPA) is necessary for treatment decisions and clinical trials. We have designed a disease activity score (ENT/GPA DAS) for this purpose. A prospective cross-sectional study. GPA patients seen in a tertiary center were systematically assessed for disease activity and/or infection in the ear, nose, and throat region using European Vasculitis Study Group guidelines. An ENT disease activity score was developed and validated, and compared to the ENT domain of the Birmingham Vasculitis Activity Score (ENT/BVAS). One hundred forty-four patients were studied, of whom 87% (125/144) had ENT involvement. ENT items of disease activity were correlated with expert clinical assessment. Discriminant correlation tests were performed to control for infection. Six items were retained to form the ENT/GPA DAS: reported bloody rhinorrhoea, granulation, ulcers and/or friable mucosa in the upper airway on endoscopic evaluation, objective stridor, sudden sensorineural hearing loss, and inflamed tympanic membrane/middle ear without infection. Nasal crusting was excluded. Individual items of ENT/GPA DAS had higher sensitivities and comparable specificities in predicting disease activity than ENT/BVAS items. Overall ENT/GPA DAS demonstrated higher sensitivity and lower specificity for disease activity in ENT/GPA when compared to overall ENT/BVAS. A tool to assess ENT disease activity in GPA has been developed. It is potentially superior to existing tools but requires further testing for intra- and interobserver reliability.