260. Which one is important in thoracic CT findings; ANCA subtype or subgrups of ANCA-associated vasculitis?
Creators: name: Ediboğlu1, Elif Durak
name: Karasu2, Sebnem
name: Tuğçe Ekici2
name: Öz3, Hande Ece
name: Solmaz1, Dilek
name: Gümüş2, Cesur
name: Akar1, Servet
Publisher: name: Zenodo
Year: 2022
Subjects: Vasculitis
ANCA
Abstracts
Giant Cell Arthritis
MPA
GPA
EGPA
Takayasu
IgA vasculitis

description: <strong>Objectives:</strong> Antineutrophil cyctoplasmic antibody (ANCA) associated vasculitdes (AAV) are a group of systemic vasculitis and associated with ANCA. Myeloperoxidase ANCA (MPO-ANCA) is mostly associated with microscopic polyangiitis (MPA) and proteinase-3 ANCA (Pr3-ANCA) is associated with granulomatosis with polyangiitis (GPA). Pulmonary involvement is one of the most common presentation in AAV. In recent years, the differences of clinical characteristics and organ involvement in ANCA subtype groups (MPO-ANCA and Pr-3 ANCA group) have been subject of research. We aimed to investigate the impact of ANCA subtype or diagnosis of GPA or MPA on thoracic computed tomography (CT) findings in patients with AAV. <strong>Methods:</strong> Patients with AAV who had thoracic CT at the time of the diagnosis or relapse (n=116) were studied and patients who had anormal thoracic CT findings (n=64) were involved. Demographic, clinical and serological data were collected retrospectively. Radiological patterns of pulmonary involvement were evaluated by two expert pulmonary radiologists. Intra- or inter-observer variation was calculated. Binary logistic regression was performed to identify ANCA subtype or AAV subtypes related finding in thoracic CT. <strong>Results:</strong> Sixty four patients with AAV (57.8% with GPA, 42.2% with MPA, 70.3% male, median [IQR] age at diagnosis 56 [21]) were involved. In patients with MPA, 15 (55.6%) of them MPO-ANCA positive, 3 (11.1%) Pr-3 ANCA positive and 9 (33.3%) were ANCA negative. In patients with GPA, 30 (81.9%) of them Pr-3 positive, 4 (10.8%) MPO-ANCA positive, 3 (8.1%) were ANCA negative. When we analyzed patients according to ANCA subgroups the most common abnormal findings were consolidation (51.5%), nodules (54.5%), cavities (27.3%) and ground glass opacity (27.3%) in Pr3-ANCA positive patients. Interlobular septal thickening (ILST) (55.6%), bronchiectasis (52.6%) and ground glass opacity (47.4%) were common findings in MPO-ANCA positive patients. Bronchiectasis, mosaic attenuation, reticulation, honeycombing and interlobular septal thickening were more common in MPO-ANCA positive group than Pr-3 ANCA positive group. However, the percentage of nodules and cavities were not statically different in MPO-ANCA positive and Pr3-ANCA positive groups (Table). When we performed multivariate analysis by binary logistic regression, honeycombing was the only independent determinant (B:-3.060; CI%95 [0.02-0.881], p=0.041) in ANCA subtype. Moreover, we analyzed patients in two diagnostic groups (GPA or MPA) we found that nodules (64.9%), consolidation (48.6%) and cavities (37.3) were common in patients with GPA; ILST (42.3%), bronchiectasis (40.7%) and consolidation (40.7%) were common in patients with MPA. Honeycombing was common in MPA group meanwhile nodules and cavities were more frequent in GPA group (Table). When we performed multivariate analysis by binary logistic regression, there was no independent finding between subgroups of AAV. <strong>Conclusion:</strong> Our results showed that if we classified AAV patients according to ANCA subtypes honeycombing was the only independent determinant in favor of MPO-ANCA positive group. However, in subgroups of AAV there was no independent determinant in thoracic CT. <strong>Disclosures:</strong> None <strong>Table.</strong> Thoracic CT findings according to subtypes of ANCA and subgroup of ANCA-associated vasculitis Variables, n (%) MPO-ANCA (+) (n=19) Pr3-ANCA (+) (n=33) <em>p</em> MPA (n=27) GPA (n=37) <em>p</em> Ground glass opasity 9 (47.4) 9 (27.3) 0.23 10 (37.0) 9 (24.3) 0.29 Reticulation 8 (44.4) 3 (9.1) 0.003 8 (30.8) 4 (10.8) 0.06 Interlobular septal thickening 10 (55.6) 6 (18.2) 0.01 11 (42.3) 7 (18.9) 0.05 Peribronchial thickening 3 (16.7) 3 (9.1) 0.65 3 (11.5) 4 (10.8) 1.0 Honeycombing 7 (36.8) 1 (3.1) 0.001 7 (25.9) 2 (5.6) 0.03 Bronchiectasis 10 (52.6) 6 (18.2) 0.014 11 (40.7) 9 (24.3) 0.18 Consolidation 8 (42.1) 17 (51.5) 0.57 11 (40.7) 18 (48.6) 0.62 Nodules 7 (36.8) 18 (54.5) 0.26 6 (22.2) 24 (64.9) 0.001 Cavities 2 (10.5) 9 (27.3) 0.29 0 14 (37.8) &lt;0.001 Eymphysema 5 (26.3) 4 (12.1) 0.26 8 (29.6) 4 (10.8) 0.10 Mosaic attenuation pattern 4 (21.1) 0 0.014 3 (11.1) 1 (2.7) 0.30 Lymph node adenopathy 6 (31.6) 7 (22.6) 0.52 6 (23.1) 9 (25.0) 1.0 Pleural effusion 2 (10.5) 3 (9.1) 1.0 6 (22.2) 3 (8.1) 0.15 Pericardial effusion 0 4 (12.1) 0.28 0 4 (10.8) 0.13 <strong>Objectives:</strong> Antineutrophil cyctoplasmic antibody (ANCA) associated vasculitdes (AAV) are a group of systemic vasculitis and associated with ANCA. Myeloperoxidase ANCA (MPO-ANCA) is mostly associated with microscopic polyangiitis (MPA) and proteinase-3 ANCA (Pr3-ANCA) is associated with granulomatosis with polyangiitis (GPA). Pulmonary involvement is one of the most common presentation in AAV. In recent years, the differences of clinical characteristics and organ involvement in ANCA subtype groups (MPO-ANCA and Pr-3 ANCA group) have been subject of research. We aimed to investigate the impact of ANCA subtype or diagnosis of GPA or MPA on thoracic computed tomography (CT) findings in patients with AAV. <strong>Methods:</strong> Patients with AAV who had thoracic CT at the time of the diagnosis or relapse (n=116) were studied and patients who had anormal thoracic CT findings (n=64) were involved. Demographic, clinical and serological data were collected retrospectively. Radiological patterns of pulmonary involvement were evaluated by two expert pulmonary radiologists. Intra- or inter-observer variation was calculated. Binary logistic regression was performed to identify ANCA subtype or AAV subtypes related finding in thoracic CT. <strong>Results:</strong> Sixty four patients with AAV (57.8% with GPA, 42.2% with MPA, 70.3% male, median [IQR] age at diagnosis 56 [21]) were involved. In patients with MPA, 15 (55.6%) of them MPO-ANCA positive, 3 (11.1%) Pr-3 ANCA positive and 9 (33.3%) were ANCA negative. In patients with GPA, 30 (81.9%) of them Pr-3 positive, 4 (10.8%) MPO-ANCA positive, 3 (8.1%) were ANCA negative. When we analyzed patients according to ANCA subgroups the most common abnormal findings were consolidation (51.5%), nodules (54.5%), cavities (27.3%) and ground glass opacity (27.3%) in Pr3-ANCA positive patients. Interlobular septal thickening (ILST) (55.6%), bronchiectasis (52.6%) and ground glass opacity (47.4%) were common findings in MPO-ANCA positive patients. Bronchiectasis, mosaic attenuation, reticulation, honeycombing and interlobular septal thickening were more common in MPO-ANCA positive group than Pr-3 ANCA positive group. However, the percentage of nodules and cavities were not statically different in MPO-ANCA positive and Pr3-ANCA positive groups (Table). When we performed multivariate analysis by binary logistic regression, honeycombing was the only independent determinant (B:-3.060; CI%95 [0.02-0.881], p=0.041) in ANCA subtype. Moreover, we analyzed patients in two diagnostic groups (GPA or MPA) we found that nodules (64.9%), consolidation (48.6%) and cavities (37.3) were common in patients with GPA; ILST (42.3%), bronchiectasis (40.7%) and consolidation (40.7%) were common in patients with MPA. Honeycombing was common in MPA group meanwhile nodules and cavities were more frequent in GPA group (Table). When we performed multivariate analysis by binary logistic regression, there was no independent finding between subgroups of AAV. <strong>Conclusion:</strong> Our results showed that if we classified AAV patients according to ANCA subtypes honeycombing was the only independent determinant in favor of MPO-ANCA positive group. However, in subgroups of AAV there was no independent determinant in thoracic CT. <strong>Disclosures:</strong> None <strong>Table.</strong> Thoracic CT findings according to subtypes of ANCA and subgroup of ANCA-associated vasculitis Variables, n (%) MPO-ANCA (+) (n=19) Pr3-ANCA (+) (n=33) <em>p</em> MPA (n=27) GPA (n=37) <em>p</em> Ground glass opasity 9 (47.4) 9 (27.3) 0.23 10 (37.0) 9 (24.3) 0.29 Reticulation 8 (44.4) 3 (9.1) 0.003 8 (30.8) 4 (10.8) 0.06 Interlobular septal thickening 10 (55.6) 6 (18.2) 0.01 11 (42.3) 7 (18.9) 0.05 Peribronchial thickening 3 (16.7) 3 (9.1) 0.65 3 (11.5) 4 (10.8) 1.0 Honeycombing 7 (36.8) 1 (3.1) 0.001 7 (25.9) 2 (5.6) 0.03 Bronchiectasis 10 (52.6) 6 (18.2) 0.014 11 (40.7) 9 (24.3) 0.18 Consolidation 8 (42.1) 17 (51.5) 0.57 11 (40.7) 18 (48.6) 0.62 Nodules 7 (36.8) 18 (54.5) 0.26 6 (22.2) 24 (64.9) 0.001 Cavities 2 (10.5) 9 (27.3) 0.29 0 14 (37.8) &lt;0.001 Eymphysema 5 (26.3) 4 (12.1) 0.26 8 (29.6) 4 (10.8) 0.10 Mosaic attenuation pattern 4 (21.1) 0 0.014 3 (11.1) 1 (2.7) 0.30 Lymph node adenopathy 6 (31.6) 7 (22.6) 0.52 6 (23.1) 9 (25.0) 1.0 Pleural effusion 2 (10.5) 3 (9.1) 1.0 6 (22.2) 3 (8.1) 0.15 Pericardial effusion 0 4 (12.1) 0.28 0 4 (10.8) 0.13