Ab0786 Association Between Angiotensin-Converting Enzyme Values and Epidemiological Features, Organ and Multi-Organ Involvement in Sarcoidosis: A Single- Center Retrospective Study

Background: Sarcoidosis is a systemic granulomatous disease that primarily affects the lungs, but it can also manifest as extra-thoracic and multi-organ involvement. Angiotensin-converting enzyme (ACE) is the best well-known biomarker in sarcoidosis. However, the link between ACE levels and organ/multi-organ involvement is still unclear. Therefore, identifying predictors of elevated ACE levels is currently an area of interest. Objectives: To analyze the association between ACE levels at diagnosis with epidemiology, pulmonary involvement, extra-thoracic and multi-organ involvement in a cohort of patients with sarcoidosis. Methods: A retrospective single-center series of patients diagnosed with sarcoidosis between 2010 and 2022 based on the WASOG 1999 criteria was conducted. Lung involvement was measured using the Scadding scale. Extra-thoracic disease was determined at diagnosis using the 2014 WASOG assessment instrument, and the involvement of three or more organs was considered as multi-organ disease. Elevated ACE titers were defined as values exceeding 52 IU/L. To identify factors predicting higher ACE levels, univariate and multivariate logistic regression models were conducted. Variables with a p <0.20 in the univariate analysis were selected for inclusion in the multivariate model. Results: Among 177 patients with sarcoidosis, 103 were female (58.2%) and 74 male (41.8%) with a mean age of 50.28 years (SD±16.25). Lung involvement was observed in 160 individuals (90.4%), followed by cutaneous affection in 69 (39%) and lymphadenopathies in 28 (15.8%). Multi-organ involvement was noted in 29 patients (16.4%). Elevated ACE titers were present in 117 patients (66.1%). Baseline demographics and prevalence of pulmonary, extra-pulmonary and multi-organ involvement categorized by ACE levels are shown in Table 1. Non-Caucasian people showed more frequently elevated ACE levels (14.5% vs. 3.3%). Regarding pulmonary involvement, ACE levels were higher in stage II patients (57.3% vs. 45%) and lower in stage IV patients (6.7% vs. 2.6%). Patients with extra-thoracic adenopathies (18.8% vs. 10%), central nervous system (7.7% vs. 1.7%) and ocular (11.1% vs. 1.7%) manifestations demonstrated higher ACE levels. Nevertheless, skin involvement showed lower ACE levels (48.3% vs. 34.2%). ACE levels were more frequently elevated in patients with multi-organ sarcoidosis (21.4% vs. 6.7%). In the evaluation of the correlation between ACE levels and the number of affected organs, it is observed that the higher the number of organs affected, the higher the average biomarker levels (Figure 1). Multivariate analysis revealed that predictors of higher ACE titers were: multi-organ involvement (OR=4.99 [95% CI: 1.56-15.96]), non-Caucasian ethnicity (OR=4.9 [95% CI: 1.04-23.25]), non-cutaneous involvement (OR=2.55 [95% CI: 1.27-5.12]), and younger age (OR=1.02 [95% CI: 1.00-1.04]). Conclusion: Our data indicates that younger individuals, patients with multi-organ involvement and non-Caucasian ethnicity have significantly higher ACE titers. In contrast, low ACE levels were associated with skin involvement. These results emphasise the interest of considering multi-organ affections in individuals with elevated ACE titers. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.