Exploring The Relationship Of Urinary Vascular Cell Adhesion Molecule-1 With Lupus Nephritis Disease Activity Over Time

Background Juvenile-onset Systemic Lupus Erythematous (JSLE) is a complex autoimmune condition, affecting the kidneys in up to 80% of cases (Lupus Nephritis (LN)) [1]. Renal histology is currently the gold standard for diagnosis and monitoring LN. Conventional markers fail to adequately track LN disease activity over time. Urinary Vascular Cell Adhesion Molecule-1 (VCAM-1) has been shown to cross-sectionally differentiate between adult SLE patients with active LN and inactive LN [2], but has not been assessed longitudinally. Objectives To assess whether urinary VCAM-1 can predict changes in the LN disease activity longitudinally. Methods Urinary concentration of VCAM-1 was quantified by enzyme-linked immunosorbent assay in JSLE patients participating in the UK JSLE Cohort Study. Patients were aged Results 58 JSLE patients were recruited to this study and followed over a median of 2.3 clinic visits [Interquartile range (IQR) 1.6-2.8]. 66% had stable disease, 10% had persistently active LN and 24% fluctuated between active and inactive LN. Median VCAM-1 levels were significantly different between patients with persistently active LN (29.5pg/mgCr [IQR 9.2-91.2]) and persistently inactive LN (4.3pg/mgCr [IQR 1.2-15.3] ( p )). Multinomial regression showed a significant difference in VCAM-1 depending on whether a patient9s LN worsened, improved or remained stable over time ( p=0.028 ). Urinary VCAM-1 level below 8.98pg/mgCr predicted an improvement in renal disease activity (sensitivity 76%, specificity 77% and an area under the curve =0.895). Conclusions Our work has shown that urinary VCAM-1 levels differentiate between JSLE patients with worsened, improved or stable LN disease activity over time, representing a good predictor of LN improvement. It is anticipated that biomarker led monitoring and treatment will improve future LN management and outcomes. References Watson L, Leone V, Pilkington C, et al. Disease activity, severity, and damage in the UK Juvenile-Onset Systemic Lupus Erythematosus Cohort. Arthritis Rheum 2012;64(7):2356-65. Howe HS, Kong KO, Thong BY, et al. Urine sVCAM-1 and sICAM-1 levels are elevated in lupus nephritis. Int J Rheum Dis 2012;15(1):13-6. Disclosure of Interest None declared