Abstract
Lupus is an autoimmune disease that has various manifestations in various organs. One of the manifestations of lupus is lupus nephritis (LN), which often causes kidney failure and death. Cytokines play an essential role in the pathogenesis of LN and might be helpful for LN biomarkers. This study aimed to evaluate urine TNF-like weak inducer of apoptosis (TWEAK) for detecting LN since this is not an invasive procedure and is more cost-effective. The gold standard procedure for diagnosing LN needs a biopsy of the kidney. However, the procedure is invasive, high cost, and takes time. Thus, a biomarker from urine is needed for early diagnosis of LN. This research conducted was cross-sectional. The total participants were 57, consisting of 29 lupus nephritis and 28 lupus without nephritis. TWEAK levels were determined by ELISA method; urine protein, urine erythrocyte, and leukocyte were examined by a urine autoanalyzer. Statistical analysis using Mann-Whitney, Spearman correlation, Kruskal-Wallis, ROC curve analysis, and a 2 × 2 contingency table. This study showed a significant difference in TWEAK levels between lupus nephritis and lupus without nephritis (p < 0.05), but no significant difference between TWEAK level and renal domain scores of SLEDAI. There were significant correlations between TWEAK level and urine erythrocyte and urine protein, but there was no significant correlation with urine leukocytes. The sensitivity and specificity of TWEAK for determining LN were 72.4% and 72.5%, respectively, with AUC 0.77. TWEAK had a good diagnostic test for detecting lupus nephritis and substantially correlated with urine erythrocyte and urine protein.