259. Are there any different findings in AAV-related pulmonary involvement in comparison with CTD or IPF
Creators: name: Ediboğlu1, Elif Durak
name: Karasu2, Sebnem
name: Tuğçe Ekici2
name: Turan3, Muzaffer Onur
name: Solmaz1, Dilek
Publisher: name: Zenodo
Year: 2022
Subjects: Vasculitis
ANCA
Abstracts
Giant Cell Arthritis
MPA
GPA
EGPA
Takayasu
IgA vasculitis

description: <strong>Background:</strong> Patients with ANCA associated vasculitis (AAV) have a wide spectrum of pulmonary involvement from parenchymal necrotizing granuloma formation, trecheobronchial inflammation, pulmonary capillaritis to interstitial lung disease. Pulmonary involvement is relatively common in connective tissue diseases (CTDs). Both rheumatologic disorders and idiopatic pulmonary fibrosis (IPF) might cause the usual interstitial pneumonia (UIP) pattern. However, little is known regarding the clinical and radiologic similarities/ dissimilarities of those diseases. We aimed to evaluate the thoracic computed tomography (CT) findings of patients with AAV, CTDs-related interstitial lung disease (ILD) or IPF. <strong>Methods:</strong> Patients whose thoracic CT performed at the time of the diagnosis or relapse of AAV (n=64), at the time of the diagnosis of CTD related ILD (n=55) or IPF (n=52) were included in the analysis. Demographic, clinical and serological data were collected retrospectively. Radiological patterns of pulmonary involvement were evaluated by two expert pumonary radiologists and abnormal thoracic CT findings were classified according to Fleischner Society guidelines. Intra- and inter-observer variation were calculated. Multonominal logistic reggresion was performed to identfy disease specific findings in thoracic CT. <strong>Results:</strong> A total of 171 patients were involved and of them 64 patients (57.8% with granulomatosis with polyangiitis, 42.2% with microscopic polyangiitis) in AAV group, 55 patients in CTD related ILD (50.9% with scleroderma, 40.0% with rheumatoid arthritis, 9.1% other or undifferensiye connective tisue disease) group and 52 patients in IPF group. Demographic and thoracic CT findings were summarized in table 1. In univariate analysis according to Fleishner Society definition, patients with AAV had more common pulmonary noduls, cavities, consolidation. However, patients with AAV were less likely to have interlobular septal thickening (ILST), lymph node adenopathy (LAP) and reticulation compared to both CTD related ILD and IPF. In multivariate analysis with multinominal logistic reggresion, the presence of nodul and consolidation and the absence of ILST and mediastinal LAP were independent determinant findings in thoracic CT in patients with AAV in comparison with both CTD related ILD or IPF (Table 2). <strong>Conclusions:</strong> The results of this study show that in additon to clinical and labaratory characteristics, some thoracic CT imaging findings like the presence of nodules and consolidation and the abscence of LAP and ILST may be useful to differentiate pulmonary involvement of AAV from other relatively common rheumatologic conditions and IPF. <strong>Disclosures:</strong> None <strong>Table 1.</strong> Demographic characteristics and Thoracic CT findings of patients AAV patients (n=64) CTD related ILD (n=55) IPF (n=52) p Characteristics Age at diagnosis, yrs, mean (SD) 58.6 (15.0) 61.8 (12.0) 72.4 (9.4) &lt;0.001 Sex, male, % 70.3 30.9 75 &lt;0.001 Smoking, ever, % 77.8 26.5 62.8 0.29 Chest CT findings according to Fleishner guideline, % Ground glass opasity 30.2 38.2 9.6 0.019 Reticulation 19.4 52.7 94.2 &lt;0.001 Interlobular septal thickening 29.0 69.1 98.1 &lt;0.001 Peribronchial thickening 11.3 20.0 3.8 0.27 Honeycombing 14.5 25.5 63.5 &lt;0.001 Bronchiectasis 31.7 47.3 86.5 &lt;0.001 Consolidation 46.8 12.7 5.8 &lt;0.001 Micronodules 6.6 3.6 0 0.06 Nodules 48.4 10.9 3.8 &lt;0.001 Cavities 22.6 0 0 &lt;0.001 Eymphysema 19.4 7.3 19.2 0.91 Mosaic attenuation pattern 6.5 20.0 38.5 &lt;0.001 Mediastinal lymph node adenopathy 26.8 53.7 57.7 0.001 Pleural effusion 15 1.8 0 0.001 Pericardial effusion 6.7 9.1 0 0.14 <strong>Table 2.</strong> Multinominal logistic regression analysis of ANCA-associated vasculitis compared with both CTD-related ILD and IPF AAV vs CTD-related ILD AAV vs IPF B (CI 95%) p B (CI 95%) p Interlobular septal thickening -1.723 (0.052-0.609) 0.006 -4.231 (2.765- 107.681) 0.002 Nodules 3.116 (4.682-108.635) &lt;0.001 4.744 (12.246-1076.944) &lt;0.001 Bronchiectasis 0.188 (0.363-4.013) 0.76 -1.728 (0.040-0.789) 0.023 Consolidation 2.475 (3.144- 44.944) &lt;0.001 2.848 (2.765-107.681) 0.002 Mediastinal lymph node adenopathy -2.113 (0.030- 0.487) 0.003 -1.867 (0.032- 0.743) 0.020