Objective Lupus nephritis (LN) is a significant consequence of systemic lupus erythematosus (SLE). To the best of our knowledge, this is the first work that focuses on evaluation of serum interleukin (IL-) 21 as a diagnostic biomarker of LN activity, compared to B lymphocyte stimulator (BlyS), tumor necrosis factor ligand superfamily member 13 (TNF-SF13), and traditional techniques of active LN attempting to compare their diagnostic usefulness. Methods Serum levels of IL-21, BlyS, and TNF-SF13 during LN were investigated. Twenty-five biopsy-proven, active LN female patients and 15 SLE patients without active LN and 20 healthy controls (HCs) joined this work. Results Serum IL-21 level was significantly higher in active LN group than in inactive LN group. Correlation analysis showed that serum IL-21 levels were significantly correlated with total SLEDAI (r = 0.41, p = 0.03), renal-SLEDAI (r = 0.48, p = 0.04), renal activity index (AI) (r = 0.93; p < 0.001), and 24-h proteinuria (r = 0.51; p > 0.008). Receiver operating characteristic curve (ROC) revealed the ability of serum IL-21 to discriminate between active and inactive LN with 70% sensitivity at >240 pg/ml cutoff point (AUC 0.809). Conclusion For Egyptian SLE patients, serum levels of IL-21 were superior to TNF-SF13 and BlyS and correlated significantly with the activity indexes of LN, indicating a promising role as a potential biomarker of active LN.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.