Pos1098 Lung Involvement and Microvascular Retinal Damage in Anca-Associated Vasculitis

Background: ANCA-associated vasculitides (AAVs) are characterized by small blood vessel inflammation resulting in organ damage. Evidence suggests that positivity to ANCA antibodies could affect clinical phenotype. Pulmonary involvement is frequent and variable among AAV manifestations. Radiological findings, mainly computed tomography (CT) images, represent key tools for the detection of lung involvement, including interstitial lung disease (ILD), nodules, tracheobronchial inflammation, and alveolar hemorrhage. Lung diseases are a relevant factor for the overall outcome and the treatment-related damage in AAV. As previously documented, subclinical microvascular retinal changes occur in AAV patients as a disease-related damage thus correlating with the burden of the disease. Microvascular retinal changes might correlate with ANCA positivity and lung involvement in AAV patients. Objectives: In this study, we aimed to explore potential associations between retinal changes and ANCA positivity in AAV patients. In addition, retinal abnormalities have been analyzed in accordance with lung diseases. Methods: An observational study was conducted on consecutive patients who met the following inclusion criteria: i. a defined diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA), granulomatosis with polyangiitis (GPA), and microscopic polyangiitis (MPA); ii. age ≥ 18 ≤ 75 yrs; iii. no ophthalmological disorders. Retinal changes have been documented by Optical coherence tomography angiography (OCT-A) that registered a quantitative analysis of vessel density (VD) in both superficial and deep capillary plexi. Lung diseases was defined as the presence of ILD, nodules, tracheobronchial inflammation, and alveolar hemorrhage by using CT scans. Continuous variables were compared with T test, categorical variables by using Chi-square or Fisher's exact test. PResults: A total of 25 AAV patients were included. 14 patients (56%) were ANCA positive (79% p-ANCA and 21% c-ANCA). Of the whole cohort, 15 patients (60%) had lung involvement, with ANCA positivity in 80% of them (75% p-ANCA). Data from the study cohort were reported in Table 1. A longer diagnostic delay was observed in ANCA-negative patients than in ANCA-positive (96.9 ± 88 months vs 25 ±36 months, P=0.01). At the OCT-A study, ANCA-negative patients showed a significantly lower foveal vascular density, documented in both the superficial (SFD) and the deep (DFD) scans, compared to ANCA-positive patients (p= 0.007 and p= 0.009, respectively). Among patients with lung involvement, ILD was documented in 33.3% of patients, tracheobronchial inflammation in 33.3%, nodules in 26.7%, and alveolar hemorrhage in a single case. Patients with lung involvement had a lower diagnostic delay than patients without (23 ±37.72 months vs 80.54 ± 80.1 months, p=0.04). Moreover, AAV patients without lung involvement had lower values of both SFD and DFD than patients with lung involvement (p Conclusion: This is the first OCT-A study in AAV patients highlighting differences in retinal microvascular network between ANCA-negative and ANCA-positive patients as well as potential correlation with concomitant lung diseases. Our preliminary findings support the idea that the presence of ANCA and/or lung involvement in AAV could reduce the diagnostic delay by increasing the index of suspicion. Therefore, the early diagnosis of AAV vasculitis could improve the therapeutic management leading to a reduced retinal vessels damage.REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.