POS0807\u2005RETINAL VESSEL CALIBERS AS A NON-INVASIVE BIOMARKER OF INFLAMMATORY BURDEN IN PRIMARY SYSTEMIC VASCULITIS

Abstract

Primary Systemic Vasculitides (PSV) constitute a heterogeneous group of rare and potentially life-threatening autoimmune diseases, characterized by a varying degree of inflammatory response, leading to local or generalized vascular disease. Vessel involvement accounts for the micro- and macrovascular complications of the disease, along with the classic risk factors including, among others age and chronic use of steroids (1). Early identification of high-risk patients for cardiovascular disease (CVD) development and the contribution of inflammation towards this adverse outcome are still unmet needs. Alterations of retinal microcirculation have been independently associated with increased CVD risk in the general population (2). The potential changes of retinal vasculature and their association with disease activity and the magnitude of inflammation have not been studied in PSV so far.To explore the effect of disease activity and inflammation on retinal microcirculation in PSV, classified according to vessel size as large, medium or small vessel vasculitides (LVV, MVV or SVV respectively), and polymyalgia rheumatica (PMR) without vasculitis.Fifty-nine patients, 43 with active disease [30 active vasculitis (12 LVV, 4 MVV, 14 SVV) and 13 PMR] and 16 with chronic inactive disease (13 vasculitis, 3 PMR) were studied. All patients were matched at 1:1 ratio with 59 controls, without underlying autoimmune/autoinflammatory disorder, neoplasia or infection, according to age, gender, CVD history, BMI, smoking, arterial hypertension, dyslipidemia, diabetes mellitus and treatment related to comorbidities. A total of 32 rheumatoid arthritis (RA) patients with mild to moderate inflammatory component as defined by standard of care acute phase reactants (ESR and CRP) and 16 chronic RA patients with normal ESR and CRP levels, matched 1:1 according to all the above parameters with 32 active and 16 inactive vasculitis/PMR patients respectively, served as disease controls. Digital retinal images were obtained and retinal vessel calibers were measured with a validated software to determine central retinal arteriolar and venular equivalents ratio (CRAE and CRVE respectively). For 16 patients with active vasculitis/PMR, retinal examination was performed in two time points (baseline and ≤ 6 months later).In the overall population, patients with active Vasculitis/PMR had increased CRVE (213.8±21.7 vs 201.3±17.1, p<0.001) and CRAE (180.0±19.2 vs 164.1±17.5 p<0.001) compared to healthy controls. Separating patients according to disease type, we found that in LVV, MVV and PMR, CRAE (p≤0.05) and CRVE (p<0.05) were increased compared to control group, while in SVV only CRAE was increased (p<0.001). Interestingly, chronic patients with disease in remission displayed higher CRAE compared to matched controls (179.8±17.2 vs 169.1±11.1, p=0.006). After immunosuppressive treatment for ≤ 6 months CRVE and to a lesser extent CRAE were reduced (p=0.048 and 0.149 respectively) with a stronger statistical significance found in the Vasculitis group (p=0.026 and 0.069 respectively). Pearson’s linear correlation coefficient in active disease state (at baseline examination) revealed positive bivariate correlation only between CRVE with ESR and CRP. Patients with Vasculitis/PMR had also increased CRAE when compared to RA patients in both active and inactive disease status (182.8±19.4 vs 170.1±18.4, p<0.001 and 179.8±17.2 vs 166.3±17.9, p=0.005 respectively).Systemic inflammation alters retinal microcirculation in both a reversible (venules) and irreversible (arterioles) way, independently of PSV form. Thus, common disease specific pathogenetic mechanisms related to inflammation may be implicated in vascular remodeling. Sequential follow-up of PSV patients will address whether retinal vessel calibers may serve as a biomarker of disease activity and CVD development.[1]Argyropoulou OD et al. Curr Opin Rheumatol 2017.[2]Shaohua G et al. Current Atherosclerosis reports 2020.None declared