THU0373 The markers useful in predicting lupus nephritisin clinical practice

Background Lupus nephritis (LN) is one of the most severe clinical manifestations of systemic lupus erythematosus (SLE). LN can be found in approximately 50% of SLE patients. The renal biopsy remains the gold diagnostic standard. However non-invasive and clinically practical laboratory markers of kidney damage in this disease are sought. Objectives The aim of the study was to assess the utility of biomarkers like inflammable indicators, complement system components and albuminuria in a single urine sample for prediction of kidney involvement and disease activity in patients with SLE. Methods A prospective study included 33 patients (81.8% women) with SLE criteria according to SLICC (Systemic Lupus International Collaborating Clinics) in age of 39.0±14.3 years. Disease-duration ranged 6–60 months. We performed full physician examination and we excluded patients with active infection. The disease activity based on the SELENA-SLEDAI scale was assessed and divided into groups: low activity (L) 12 points. In the blood samples complement components (C3, C4) (g/L), C-reactive protein CRP (mg/L), interleukin 6 (IL-6) (pg/mL), serum creatinine concentration (sCr) (mg/g), ESR (mm/h), glomerulal filtration rate (eGFR) according to CKD-EPI (ml/min/1.73 m 2 ) were determined. The concentration of albumin (uAlb) (mg/dl) and creatinine sCr (g/dL) from the morning urine sample was measured and the albumin/creatinine index (uACR) (mg/g) was calculated. Based on the obtained results, patients were divided into stages of chronic kidney disease (CKD) according to .KDIGO 2012. A daily proteinuria (DP) (g/24 hour) was performed. In the assessment of statistical significance, Kruskal-Wallis or Mann-Whitney U-tests were used. Results In our study the SLE activity was as follows (%): L-24 (72.7), M-6 (18.2), H-3 (9.1). The average values (range) of biomarkers of renal function were: Cr=0,81±0,27 (0.55–1.65), eGFR=99.6±24.4 (46–131), uAlb=13.6±34.4 (0.04–161.0), uACR=121.3±356.3 (4.8–1905.3), DP=0.32±0.92 (0.015–5.3), and other biomarkers: OB=26.1±25.9 (4.0–99.0); CRP=10.3±28.1 (0.2–148.7); IL-6=7.8±14.7 (0–78.3); C3=1.08±0.36 (0.33–2.25); C4=0.16±0.09 (0.02–0.43). The study group met the CKD criteria: G1 n=21 (63.6%), G2 n=9 (27.3%), G3 n=3 (9.1%); A1 n=26 (78.8%), A2 n=3 (9.1%), A3 n=4 (12.1%). We showed a negative relationship between the eGFR and: CRP (R=-0.49, p=0.005), IL-6 (R=-0.48, p=0.005) and C4 (R=-0.43, p=0.01). There was also a significant dependence of the SLEDAI SLE activity with: uAlb (L, H) (p=0.04), DP (M, H) (p=0.03), uACR in the whole study group (p=0.04) and between uACR and DP (p=0.0003). Conclusions Our studies showed that the risk of kidney damage in SLE may depend on the concentration of CRP, IL-6, C4. In addition albuminuria (uAlb, uACR) correlates with the value of DP and SLE activity, what indicates the dominant glomerular lesion in the etiopathogenesis of proteinuria in LN. Disclosure of Interest None declared