P158 Cutaneous vasculitis in systemic lupus erythematosus: trends of incidence and risk factors

Abstract

Abstract Background/Aims Cutaneous vasculitis (CV) is the most common form of vasculitis observed in patients with SLE; however, the precise epidemiological trends and underlying risk factors remain uncertain. The aim of this study was to define the incidence, prevalence, and risk factors of CV in systemic lupus erythematosus (SLE) patients over a period of 20 years. Methods The Birmingham Lupus Cohort is a longitudinal observational cohort of patients with SLE. All patients fulfilled the 1997 ACR Updated Classification Criteria for SLE. Inception patients were recruited within three years of their fourth ACR criterion. Disease activity was assessed using the classic BILAG index and laboratory results recorded. The BILAG vascular domain was used to determine the incidence rate, which refers to the rate at which new cases of minor and major CV attributed to active SLE occur. Cox proportional hazards frailty models were developed to identify clinical and laboratory variables associated with development of CV. Results We analysed 392 patients, of whom 375 (92.5%) were females. There were 213 (55.0%) White, 72 (18.6%) African-Caribbean, 82 (21.1%) South Asian, 9 (2.3%) East Asian, and 11 (2.8%) other ethnicities. The median (IQR) age at enrolment was 33 (26 - 44) years and the median duration of follow up was 9.2 (5.1 - 14.7) years. The incidence rates of minor and major CV were reported in Table 1. In Cox proportional hazards models, there was a positive association between CV and discoid rash (hazard ratio [HR] 2.16 [95% CI: 1.01, 4.61]), Raynaud’s phenomenon (HR 5.67 [95% CI: 4.11, 7.81]), livedo reticularis (HR = 4.69 [95% CI: 1.83, 12.0]), arthritis (HR 3.02 [95% CI: 2.20, 4.15]), renal involvement (OR 2.40 [95% CI: 1.55, 3.71]), haematological involvement (HR = 2.46 [95% CI: 1.80, 3.36]), and Afro-Caribbean descent (HR 1.96 [95% CI: 1.03, 3.74]). In addition, CV was positively associated with anti-dsDNA (HR = 2.33 [95% CI: 1.67, 3.27]), low C3 or C4 (HR 2.29 [95% CI: 2.18, 4.10]), and history of anti-Ro or anti-La (HR = 1.92 [95% CI: 1.15, 3.21]). Conclusion The incidence rates of CV decrease over the duration of follow-up and are associated with defined clinical and serological features. Disclosure A. Saleh: Grants/research support; A.S. is a sponsored PhD student by the Egyptian ministry of higher education represented by The Egyptian Bureau for Cultural & Educational Affairs in London. C. Gordon: None. J. Reynolds: None.