Computed tomography findings of paranasal sinuses in patients with eosinophilic granulomatosis with polyangiitis: Comparison with other eosinophilic sinus diseases and clinical relevance of their severity

BackgroundAlthough paranasal sinuses are one of the most representative organs affected by eosinophilic granulomatosis with polyangiitis (EGPA), they have not been studied sufficiently. The aim of this study was to compare computed tomography (CT) findings in paranasal sinuses of EGPA with those of other eosinophilic sinus diseases and elucidate the clinical relevance of their severity.MethodsCT findings of paranasal sinuses in EGPA patients prior to therapeutic intervention (n = 30) were evaluated using the Lund–Mackay staging (LMS) system and compared with those of three control diseases [(NSAID-exacerbated respiratory disease (N-ERD), aspirin-tolerant asthma, and eosinophilic chronic rhinosinusitis without asthma (ECRS)]. We divided EGPA patients into three groups based on their LMS scores and examined their association with disease manifestation.ResultsTotal scores of the LMS system in EGPA were significantly lower than those of N-ERD and ECRS without asthma. There was a large variation in total LMS scores in EGPA, suggesting considerable heterogeneity of their sinus lesions. Although EGPA with low LMS system scores showed only minor findings in maxillary and anterior ethmoid regions, those with high LMS system scores were characterized by high scores in the ostiomeatal complex. However, the frequencies of patients with a Five-Factor Score ≥2 and with cardiac involvement were significantly higher for EGPA with low LMS system scores.ConclusionsAlthough paranasal sinus lesions in EGPA were less severe than those of other eosinophilic sinus diseases, their milder CT findings may be associated with a higher frequency of extra-respiratory organ involvement.     

A diagnostic score for eosinophilic granulomatosis with polyangiitis among eosinophilic disorders

BackgroundEosinophilic granulomatosis with polyangiitis (EGPA) is a form of systemic vasculitis with eosinophilic inflammation. However, existing classification criteria are all designed to classify EGPA among vasculitis and there is no established method distinguishing EGPA from other eosinophilic disorders. The aim of the present study was to propose a scoring system to differentiate EGPA among eosinophilic disorders.MethodsNon-supervised hierarchical clustering using Ward's method and principal component analysis (PCA) were performed for 19 clinical parameters of 58 patients with eosinophilia-related diseases at a tertiary university hospital. The newly proposed scoring system was externally validated in 40 patients at another tertiary institution.ResultsTwo distinct clusters were identified, and clinical features including peripheral neuropathy, asthma, skin involvement, lung involvement, rheumatoid factor (RF) positivity, myeloperoxidase (MPO)–anti-neutrophil cytoplasmic antibody (ANCA) positivity, IgE elevation, C-reactive protein (CRP) elevation, and vasculitis pathological findings were predominantly observed in one of these clusters (p < 0.05). Ten features defining the cluster with a high rate of vasculitis were weighted by PCA to create the E-CASE (EGPA classification among systemic eosinophilia) scoring system, on a 16-point scale. Based on the distribution of scores in the primary cohort, we defined an E-CASE score ≥12 as positive, ≤ 8 as negative, and 9–11 as undeterminable. The sensitivity and specificity of the E-CASE score in the validation cohort were 93.3% and 100%, respectively.ConclusionsWe developed and verified a novel scoring system for differentiating EGPA from other types of eosinophilic disorders.