Urine Monocyte Chemoattractant Protein-1(UMCP-1) as a Biomarker of Renal Involvement in Systemic Lupus Erythematosus

OBJECTIVE(S): Lupus nephritis (LN) is frequently associated with a poor long-term prognosis. Renal biopsy is the diagnostic method of choice in this condition. Urine biomarkers have been mentioned in the diagnosis of LN. The study(,)s purpose was to evaluate the performance of urinary monocyte chemoattractant protein 1(UMCP-1) as a biomarker of renal involvement in systemic lupus erythematosus. MATERIALS AND METHODS: Forty-one recently diagnosed systemic lupus erythematosus patients (8 male and 33 female) without renal involvement (group 1) and twenty six patients (8 male and 18 female) with LN (group 2), proven by biopsy, were recruited to this study. UMCP-1 sensitivity and specificity for identifying biopsy-proven nephritis were calculated, and a receiver operating characteristic (ROC) curve was constructed to quantify how definitely UMCP-1 distinguishes between patients with and without LN. RESULTS: The mean value of UMCP-1 levels were 733.07 pg/ml ± 1282.54 and 144.16 pg/ml ± 137.90 in patients with and without LN respectively. The UMCP-1 level was significantly higher in group 2 than group 1. There was no significant correlation between UMCP-1 and 24-hour urine protein (r = 0.031, P= 0.874). The area under the ROC curve was 0.727 with a CI 95% of 0.597 to 0.857 (P=0.002). Using a cut-off value of 82 pg/ml,UMCP-1 had a sensitivity of 88.5% and a specificity of 46.3% for identifying LN. CONCLUSION: UMCP-1 can serve as a biomarker of LN although further longitudinal studies of these biomarkers are required in LN.