Combined detection of uMCP-1 and uTWEAK for rapid discrimination of severe lupus nephritis

Abstract

Reliable markers for the rapid discrimination of severe renal damage remain a vital concern for lupus nephritis (LN). To determine a better tool for kidney damage detection, the present study compared the evaluation ability of novel urinary cytokines and chemokines (namely urinary monocyte chemoattractant protein 1 (uMCP-1), tumor necrosis factor-like weak inducer of apoptosis (uTWEAK)) with traditional serum or urinary markers (namely urinary alpha 1-microgrobulin (uα1-MG), beta 2-microglobulin (uβ2-MG) and serum complement C3 (C3), complement C4 (C4), creatinine (Cr), blood urea nitrogen (BUN) and cystatin C (Cys C)) in discriminating LN renal damage. Correlations between markers with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) renal SLEDAI scores, biopsy activity index (BAI) and biopsy chronicity index (BCI) scores were evaluated. Receiver operating characteristic (ROC) curves were generated to evaluate a single or combined model in discriminating active renal involvement (rSLEDAI scores > 0) and patients with poor pathological outcome (BAI scores ≥ 7). uMCP-1 and uTWEAK possess higher correlation coefficients with renal damage and larger areas under ROC curves (AUCs) than other markers. A combined model of uMCP-1 and uTWEAK showed an AUC of 0.887, sensitivity of 86.67% and specificity of 80.00% to discriminate active LN, and an AUC of 0.778, sensitivity of 75.00% and specificity of 81.82% to discriminate LN with poor outcome, which are better than the utility of any markers individually.