ADULT-ONSET STILL’S DISEASE WITH ELDERLY ONSET, RESULTS FROM A MULTICENTRE STUDY AND ASSESSMENT OF AGE INFLUENCE ON CLINICAL FEATURES AND DISEASE OUTCOMES.

Background: Aging is a physiological, multidimensional, and irreversible process, occurring in humans over time. Interestingly, multiple lines of evidence have recently suggested that some diseases, generally affecting young adults, are nowadays described in the elderly, although possibly associated with different symptoms or complications. In this context, a possible occurrence of adult onset Still’s disease (AOSD) in elderly has been suggested. This is a rare inflammatory disorder of unknown origin usually observed in young adults [1-3]. Objectives: In this study, we aimed at describing the clinical characteristics, life-threatening complications occurrence, and mortality of AOSD patients with an elderly onset. The manifestations of these patients were also compared with those with a younger onset. Furthermore, the predictive role of age was evaluated on clinical features and disease outcomes. Finally, in these patients, an assessment of associated comorbidities was also performed. Methods: A retrospective assessment of prospectively followed patients, from January 2001 to April 2021, was provided to analyse clinical features, life-threatening complications occurrence, and mortality in AOSD patients with onset in elderly. AOSD patients, who were included in multicentre Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale (GIRRCS) cohort, were evaluated. Results: Out of 221 assessed patients, 37 (16.7%) had an onset of the disease aged over than 60 years. When compared with younger patients, these were characterised by a higher prevalence of pericarditis (p=0.008), comorbidities (p<0.0001), and mortality (p=0.023). Additionally, our analysis showed that pleuritis and pericarditis positively correlated with age (coefficient=0.227, p=0.001; coefficient=0.213, p=0.001, respectively). Furthermore, the occurrence of parenchymal lung disease was significantly related with age (coefficient=0.168, p=0.012). The presence of comorbidities positively correlated with age (coefficient=0.443, p<0.0001). Moreover, age was negatively related to the polycyclic pattern (coefficient=-0.209, p=0.002). A correlation between mortality and age was also retrieved (coefficient=0.158, p=0.019). Age predicted the presence of serositis in both univariate (HR: 1.02, 95%CI: 1.01-1.03, p=0.007) and multivariate analyses (HR: 1.02, 95%CI: 1.01-1.04, p=0.007). Age was also a significant predictor of parenchymal lung disease in both univariate (HR: 1.03, 95%CI: 1.01-1.05, p=0.017) and multivariate analyses (HR: 1.03, 95%CI: 1.00-1.05, p=0.048). No significant results were observed assessing the predictive role of age on occurrence of macrophage activation syndrome. Furthermore, age resulted to be a negative predictor of polycyclic pattern only in univariate analysis (HR: 0.99, 95%CI: 0.97-1.00, p=0.048). Finally, age significantly predicted the mortality in both univariate (HR: 1.03, 95%CI: 1.00-1.06, p=0.034) and multivariate analyses (HR: 1.05, 95%CI: 1.01-1.08, p=0.012). Conclusion: Clinical features of AOSD patients with elderly onset were described in our multicentre cohort. Although the main clinical characteristics were similar comparing older and younger patients, patients aged over 60 years at disease onset were characterised by an increased prevalence of serositis, comorbidities, mostly cardiometabolic, and a higher mortality rate. Age predicted the presence of parenchymal lung disease and mortality, and it could be considered a further negative prognostic factor in AOSD. REFERENCES: [1]Mollaeian A, Chen J, et al. BMC Rheumatol. 2021;5(1):12. [2]Maruyama A, et al. Mod Rheumatol. 2021;31(4):862-868. [3]Suzuki E, et al. Tohoku J Exp Med. 2021;255(3):195-202. Disclosure of Interests: None declared Citation: , volume 81, supplement 1, year 2022, page 1006Session: Other orphan diseases (POSTERS only)