POS1395 ASSESSMENT OF MICROVASCULAR INVOLVEMENT IN LUPUS NEPHRITIS PATIENTS BY RETINAL OCT-ANGIOGRAPHY AND KIDNEY BIOPSIES

Abstract

Background:Lupus Nephritis (LN) and retinopathy are organ-threatening manifestation of Systemic Lupus Erythematosus (SLE) and both share common pathophysiology represented by microvascular damage. Optical coherence tomography angiography (OCTA) is a recent non-invasive technique showing retinal vascular damage.Objectives:To analyze retinal microvascular alterations in SLE-LN patients and investigate correlations between ocular and renal involvement.Methods:We recruited SLE-LN patients and healthy controls (HC), age and sex -matched. Patients underwent rheumatological evaluation, including clinical, laboratory, kidney function and kidney biopsies examination.Patients and HC underwent a complete ophthalmological evaluation including eye definition color retinography and OCTA whole image, parafovea and fovea vessel density assessment of superficial and deep retinal capillary plexus. Parafovea and fovea thickness, fovea avascular zone (FAZ) area and perimeter were detected.Statistical analysis was performed using: χ2 test, unpaired t-test, Mann Whitney U test, Pearson or Spearman rank correlation and ROC curve analysis.Results:48 eyes of 24 SLE-LN patients and 44 eyes of 21 HC were evaluated. Table 1 shows demographic, clinical, laboratory and histological parameters.Figure 1 shows results of OCTA data and relative AUC curves and ROC analysis. Analysis of OCTA data showed a significative reduction of vessel density in SLE-LN compared to HC regarding the following parameters: superficial whole en face, parafovea and fovea density (Figure 1A-C), deep whole en face and deep fovea density, (Figure 1D-E), parafovea and fovea thickness (Figure 1F-G), FAZ area and perimeter (Figure 1H-I).OCTA data were correlated with demographic, clinical and histologic features of patients showing negative correlation between: SLE duration and both superficial (p=0.03; r=-0.3) and deep (p= 0.004; r=-0.4) whole en face density; LN duration and superficial whole en face (p=0,05; r=-0.4) and parafovea (p=0.007; r=-0.4) density, deep whole en face (p=0.004; r=-0.4) and fovea (p=0.01; r=-0.4) density and parafovea thickness (p=0.004; r=-0.3); SLEDAI-2K and both superficial and deep fovea density (p<0.0001, r=-0.6 and p=0.0, r=-0.4 respectively); BUN and superficial whole en face density (p=0.003; r=-0.5) and parafovea (p=0.004; r=-0.4) density and deep fovea density (p=0.03; r=-0.3); serum creatinine and deep whole en face density (p=0.004; r=-0.4).Positive correlation was found between LN duration and FAZ area (p= 0.01; r= 0.4); creatinine clearance and both deep whole en face (p=0.05; r= 0.3) and fovea (p=0.0007; r= 0.5) density.OCTA data analysis showed a reduction in superficial (p=0.02) and deep (p=0.009) whole en face density in patients with LN-vascular lesions assessed by kidney biopsy. In this group, patients with intimal hyalinosis showed a reduction in deep whole en face density (p=0.04) compared to those without intimal hyalinosis.Conclusion:Preliminary results suggest a correlation between retinal microvascular alterations and kidney function and histologic lesions encouraging the use of OCTA measurement as a potential biomarker of systemic vascular involvement.Table 1.SLEN=24HCN=21P valueAge (years)44.4±13.838.3±10.4nsFemale (n/%)21/87.517/81nsBCVA (logMAR)0.01± 0.050.0 ± 0.1nsDisease duration (months)177.6± 126.6/LN duration (months)108 ± 97/SLEDAI-2K6.8±5/Creatininemia (mg/dl)0.9±0.3/BUN (mg/dl)39,6±17.6/Creatinine clearance (ml/min)99.2±53.7/Proteinuria (mg/24h)432.8±524.5/GMN class III-IV (n/%)19/77.7/GMN class III-V (n/%)5/22.2/Kidney biopsy active lesions (n/%)15/62.5/Kidney biopsy chronic lesions (n/%)15/62.5/Kidney biopsy vascular lesions (n/%)8/33.3/Kidney biopsy intimal hyalinosis (n/%)7/29/Moderate stage lupus retinopathy (n/%)20/83.3/Severe stage lupus retinopathy (n/%)3/12.5/BCVA: best-corrected visual acuity, SLEDAI-2K: Systemic Lupus Erythematosus Disease Activity Index 2000, BUN: blood urea nitrogen; GMN: glomerulonephritisDisclosure of Interests:None declared