A Novel Method for Assessing Sinusitis Activity in Minimally Symptomatic Patients with ANCA-Associated Vasculitis: A Pilot Study

<b>Objectives</b>: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of vasculitides sharing a common pathophysiology, which affects small and medium blood vessels. Sinonasal involvement is one of the most common manifestations of AAV. The goal of this study was to find the most suitable method to assess paranasal sinus changes in a group of patients with ANCA-associated vasculitis and renal involvement. Subjective scales like Lund-Mackay and Zinreich were compared with a three-dimensional (3D) volumetric method. Pre- and post-treatment computer tomography were compared. <b>Methods</b>: Computer tomography, nasal symptoms, and endoscopy of 28 patients hospitalized at the Department of Internal Diseases, Nephrology and Dialysis, Military Institute of Medicine-National Research Institute were assessed retrospectively. Paranasal sinus tomography was performed during treatment induction and after achieving disease remission (BVAS = 0) to assess treatment effectiveness. Radiological analysis was performed with the Lund-Mackay scoring system, Zinreich scoring system, and 3D volumetric scoring system with the usage of Slicer 3D analysis. The radiologic scoring systems were compared. <b>Results</b>: The statistically significant differences in treatment effectiveness were observed for the Zinreich scale on both the right and left side. Similar to the 3D volumetric scoring system, the right and left maxillary sinuses demonstrated statistically significant differences. On the other hand, no statistically significant differences were found between the first and second visits for the Lund-Mackay or total Global Osteitis scores on either side. The strongest correlation was achieved between the Zinreich scoring system and 3D volumetric scale. <b>Conclusions</b>: The three-dimensional CT volumetric analysis demonstrated higher SRM (standardized response mean) values than the Zinreich score on both sides, but the differences were not statistically significant. The Zinreich scoring system should be used instead of the Lund-Mackay scale in everyday clinical practice.