Background Currently, major efforts have been undertaken to identify biomarkers that can predict impending lupus renal flare, development of chronic kidney disease or reflect renal histology at the time of the flare. So, this study aims to assess the correlation of urinary biomarkers MCP1 and NGAL with the disease activity in lupus nephritis (LN).

Materials and Methods This prospective study was conducted in a tertiary care center, for a period of 9 months. 60 patients with SLE were recruited. They were divided into 3 groups, 1st group with Active Lupus Nephritis (n=22), 2nd group with Inactive Lupus Nephritis (n=20) and 3rd group consisted of SLE patients with no renal involvement (n=18). For comparison another group of age and sex matched controls was taken (n=20). Disease activity was correlated with disease activity indices, baseline characteristics and biopsy. Urinary MCP1 (UMCP1) and NGAL (UNGAL) were measured. Statistical analysis using SPSS11.5 was done to find the correlation between levels of urinary biomarkers and disease activity.

Results In patients with active LN, both UMCP1/Cr and UNGAL/Cr were significantly elevated (92.78, 76.11pg/ml, p<0.001). In both, control group and SLE without renal involvement the values of UMCP1/Cr and UNGAL/Cr were normal (24.44, 22.22pg/ml in control and 24.3, 22.80pg/ml in SLE without renal involvement). In patients with inactive LN the values of UMCP1/Cr and UNGAL/Cr were observed to be significantly higher than control (44.18, 38.45pg/ml, p<0.005) and lower than those of active LN. Values of UMCP1/Cr and UNGAL/Cr were found to be in close correlation with mean rSLEDAI scores of active LN (10) and inactive LN (3.6).

Conclusions Levels of urinary biomarkers UMCP1 and UNGAL were significantly elevated in active lupus nephritis and found to have excellent correlation with disease activity index and rSLEDAI scores.