Background and aims Treatment of LN requires an accurate assessment of disease activity.

This study aims to assess the correlation of urinary biomarkers MCP1 and NGAL with the disease activity in LN.

Methods Materials and Methods: Prospective study conducted in a tertiary care centre. 60 patients with SLE were recruited and divided into 3 groups: one with Active LN (n=22), another with Inactive LN (n=20) and third formed of SLE patients with no renal involvement (n=18). Active LN patients underwent renal biopsy. For comparison another group of age and sex matched controls was taken (n=20). Disease activity was correlated with biopsy and baseline characteristics. Urinary MCP1 and NGAL were measured and its correlation with disease activity was analysed.

Results In patients with active LN, both UMCP1/Cr and UNGAL/Cr were significantly elevated (92.78, 76.11 pg/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, 22.22 pg/ml in control and 24.3, 22.80 pg/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, 38.45 pg/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) and disease activity as per histopathology.

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